diff --git a/build.gradle.kts b/build.gradle.kts
index 38f831241..50e9196ca 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,6 @@ import dev.detekt.gradle.Detekt
 import dev.detekt.gradle.extensions.DetektExtension
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 import org.gradle.api.tasks.testing.logging.TestLogEvent
-import org.gradle.kotlin.dsl.withType
 
 plugins {
   alias(libs.plugins.kotlin.jvm)
@@ -46,12 +45,13 @@ dependencies {
   kover(project(kotestModule))
 }
 
-dokka {
-  moduleName.set("ReadingBat")
-  pluginsConfiguration.html {
-    homepageLink.set(repoUrl)
-    footerMessage.set(projectName)
-  }
+// Dokka config is root-level (aggregate docs); the plugin is applied via the plugins {} block
+// above. It can't go in allprojects {} — subprojects don't have the Dokka plugin applied until
+// the subprojects {} block below runs, so the `dokka` extension wouldn't exist yet there.
+configureDokka()
+
+allprojects {
+  configureVersions()
 }
 
 subprojects {
@@ -68,7 +68,6 @@ subprojects {
   configureKotlinter()
   configureDetekt()
   configureSecrets()
-  configureVersions()
 }
 
 fun Project.configureKotlin() {
@@ -83,6 +82,15 @@ fun Project.configureKotlin() {
   kotlin {
     jvmToolchain(jvmTargetVersion.toInt())
 
+    // Collection literals (`val x: List<Int> = [1, 2, 3]`) are an experimental Kotlin 2.4
+    // feature gated behind this flag. Removing it breaks every `[...]` literal in the
+    // sources. Note this flag applies to project sources only -- it is NOT in effect for
+    // the JSR-223 script engine that evaluates the content DSL at runtime, so DSL content
+    // files must keep using listOf()/mutableListOf().
+    compilerOptions {
+      freeCompilerArgs.add("-Xcollection-literals")
+    }
+
     sourceSets.all {
       listOf(
         "kotlin.ExperimentalStdlibApi",
@@ -202,6 +210,16 @@ fun Project.configureTesting() {
   }
 }
 
+fun Project.configureDokka() {
+  dokka {
+    moduleName.set("ReadingBat")
+    pluginsConfiguration.html {
+      homepageLink.set(repoUrl)
+      footerMessage.set(projectName)
+    }
+  }
+}
+
 fun Project.configureVersions() {
   // A pre-release qualifier is a `.` or `-` delimiter followed by a known unstable
   // keyword. `m\d` matches milestones (`-M1`/`.M2`) without catching stable classifiers
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 23057f0f4..0697cb738 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -6,24 +6,24 @@ jvm = "17"
 # Plugin versions
 buildconfig = "6.0.10"
 detekt = "2.0.0-alpha.5"
-kotlin = "2.4.0"
-kotlinter = "5.5.0"
-kover = "0.9.8"
+kotlin = "2.4.10"
+kotlinter = "5.6.0"
+kover = "0.9.9"
 dokka = "2.2.0"
 maven-publish = "0.37.0"
 versions = "0.54.0"
 
 # Library versions
-cloud = "1.28.6"
+cloud = "1.29.0"
 commons = "1.15.0"
 exposed = "1.3.1"
 flexmark = "0.64.8"
-flyway = "12.11.0"
+flyway = "13.0.0"
 github-api = "1.330"
 hikari = "7.1.0"
 java-scriptengine = "2.0.0"
 khealth = "3.0.1"
-kotest = "6.2.2"
+kotest = "6.2.3"
 ktor = "3.5.1"
 logback = "1.5.38"
 logging = "7.0.12"
@@ -31,12 +31,12 @@ pgjdbc = "0.8.9"
 playwright = "1.61.0"
 postgres = "42.7.13"
 prometheus = "0.16.0"
-prometheus-proxy = "3.2.0"
+prometheus-proxy = "4.0.0"
 python = "2.7.4"
 resend = "4.13.0"
 serialization = "1.11.0"
 testcontainers = "1.21.4"
-utils = "3.1.0"
+utils = "3.2.1"
 
 [libraries]
 # Serialization
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/common/FunctionInfo.kt b/readingbat-core/src/main/kotlin/com/readingbat/common/FunctionInfo.kt
index ceab37503..b498c4678 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/common/FunctionInfo.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/common/FunctionInfo.kt
@@ -289,7 +289,7 @@ class FunctionInfo(
      */
     internal fun splitTopLevelCommas(csv: String): List<String> {
       if (csv.isBlank()) return emptyList()
-      val elements = mutableListOf<String>()
+      val elements: MutableList<String> = []
       val current = StringBuilder()
       var quoteChar: Char? = null
       for (c in csv) {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/common/Metrics.kt b/readingbat-core/src/main/kotlin/com/readingbat/common/Metrics.kt
index 5d4da0dab..cc4b7dac5 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/common/Metrics.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/common/Metrics.kt
@@ -199,80 +199,80 @@ class Metrics {
     SamplerGaugeCollector(
       "request_timing_map_size",
       "Request timing map size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { requestTimingMap.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "geo_map_size",
       "IP Geo map size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { geoInfoMap.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "content_map_size",
       "Content map size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { contentSource().contentMap.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "user_id_cache_size",
       "User ID cache size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { userIdCache.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "user_email_cache_size",
       "User email cache size size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { emailCache.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "sources_cache_size",
       "Sources cache size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { contentSource().functionInfoMap.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "websocket_connection_list_size",
       "Websocket connection list size",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { answerWsConnections.size.toDouble() },
     )
 
     SamplerGaugeCollector(
       "active_users_1min_count",
       "Active users in last 1 min count",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { activeSessions(1.minutes).toDouble() },
     )
 
     SamplerGaugeCollector(
       "active_users_15mins_count",
       "Active users in last 15 mins count",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { activeSessions(15.minutes).toDouble() },
     )
 
     SamplerGaugeCollector(
       "active_users_60mins_count",
       "Active users in last 60 mins count",
-      labelNames = listOf(AGENT_ID),
-      labelValues = listOf(agentLaunchId()),
+      labelNames = [AGENT_ID],
+      labelValues = [agentLaunchId()],
       data = { activeSessions(1.hours).toDouble() },
     )
   }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/common/Property.kt b/readingbat-core/src/main/kotlin/com/readingbat/common/Property.kt
index 3cd589afa..376cfe39d 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/common/Property.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/common/Property.kt
@@ -133,7 +133,7 @@ open class KtorProperty(
   companion object {
     private val logger = KotlinLogging.logger {}
     private val initialized = AtomicBoolean(false)
-    private val instances = mutableListOf<KtorProperty>()
+    private val instances: MutableList<KtorProperty> = []
     internal val configStore = java.util.concurrent.ConcurrentHashMap<String, String>()
 
     // Names of properties that have individually had a value assigned via setProperty. Lets the
@@ -466,7 +466,7 @@ sealed class Property(
 
     /** Returns the ordered list of properties that should be initialized at application startup. */
     fun initProperties() =
-      listOf(
+      [
         DSL_FILE_NAME,
         DSL_VARIABLE_NAME,
         PROXY_HOSTNAME,
@@ -503,6 +503,6 @@ sealed class Property(
         GOOGLE_OAUTH_CLIENT_ID,
         GOOGLE_OAUTH_CLIENT_SECRET,
         SESSION_SECRET,
-      )
+      ]
   }
 }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ChallengeGroup.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ChallengeGroup.kt
index 62aeec4c0..0e1c911e3 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ChallengeGroup.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ChallengeGroup.kt
@@ -67,7 +67,7 @@ class ChallengeGroup<T : Challenge>(
   internal val groupNameSuffix: GroupName,
 ) {
   /** The ordered list of challenges in this group. */
-  val challenges = mutableListOf<T>()
+  val challenges: MutableList<T> = []
 
   private val groupPrefix by lazy { pathOf(languageName, groupName) }
   private val srcPath get() = languageGroup.srcPath
@@ -149,7 +149,7 @@ class ChallengeGroup<T : Challenge>(
   var includeFilesWithType by IncludeFilesWithType(this, languageType)
 
   private class IncludeFiles<T : Challenge>(val group: ChallengeGroup<T>, val languageType: LanguageType) {
-    val includeList = mutableListOf<PatternReturnType>()
+    val includeList: MutableList<PatternReturnType> = []
 
     operator fun getValue(thisRef: Any?, property: KProperty<*>) = includeList.toString()
 
@@ -166,7 +166,7 @@ class ChallengeGroup<T : Challenge>(
   }
 
   private class IncludeFilesWithType<T : Challenge>(val group: ChallengeGroup<T>, val languageType: LanguageType) {
-    val includeList = mutableListOf<PatternReturnType>()
+    val includeList: MutableList<PatternReturnType> = []
 
     operator fun getValue(thisRef: Any?, property: KProperty<*>): PatternReturnType = PatternReturnType("", Runtime)
 
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ContentDsl.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ContentDsl.kt
index 36696f675..1cddc6f49 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ContentDsl.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ContentDsl.kt
@@ -198,7 +198,7 @@ internal fun evalContentDsl(
  */
 internal fun addImports(code: String, variableName: String): String {
   val classImports =
-    listOf(ReadingBatServer::class, GitHubContent::class)
+    [ReadingBatServer::class, GitHubContent::class]
       // .onEach { println("Checking for ${it.javaObjectType.name}") }
       .filter { code.contains("${it.javaObjectType.simpleName}(") }   // See if the class is referenced
       .map { "import ${it.javaObjectType.name}" }                           // Convert to import stmt
@@ -206,14 +206,14 @@ internal fun addImports(code: String, variableName: String): String {
       .joinToString("\n")                                          // Turn into String
 
   val funcImports =
-    listOf(::readingBatContent)
+    [::readingBatContent]
       // .onEach { println("Checking for ${it.name}") }
       .filter { code.contains("${it.name}(") }  // See if the function is referenced
       .map { "import ${it.fqMethodName}" }            // Convert to import stmt
       .filterNot { code.contains(it) }                // Do not include is import already present
       .joinToString("\n")                    // Turn into String
 
-  val imports = listOf(classImports, funcImports).filter { it.isNotBlank() }.joinToString("\n")
+  val imports = [classImports, funcImports].filter { it.isNotBlank() }.joinToString("\n")
   return """
       $imports${if (imports.isBlank()) "" else "\n\n"}$code
       $variableName
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageGroup.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageGroup.kt
index f202c4726..b7adf80b7 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageGroup.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageGroup.kt
@@ -48,7 +48,7 @@ class LanguageGroup<T : Challenge>(
   val contentRoot get() = languageType.contentRoot
 
   /** The ordered list of challenge groups in this language. */
-  val challengeGroups = mutableListOf<ChallengeGroup<T>>()
+  val challengeGroups: MutableList<ChallengeGroup<T>> = []
 
   /**
    * The content source for this language's challenge files. Inherits the parent
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageType.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageType.kt
index d27f15865..1efead6c1 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageType.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/LanguageType.kt
@@ -47,7 +47,7 @@ enum class LanguageType(val useDoubleQuotes: Boolean, val suffix: String, val sr
 
   companion object {
     val defaultLanguageType = Java
-    val languageTypeList = listOf(Java, Python, Kotlin)
+    val languageTypeList = [Java, Python, Kotlin]
 
     /** Returns all language types, optionally reordered to put [defaultLanguage] first. */
     fun languageTypes(defaultLanguage: LanguageType? = null): List<LanguageType> =
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ReadingBatContent.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ReadingBatContent.kt
index a5dc884c7..e2312d59c 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/ReadingBatContent.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/ReadingBatContent.kt
@@ -77,7 +77,7 @@ import kotlin.time.measureTimedValue
 @ReadingBatDslMarker
 class ReadingBatContent {
   internal val timeStamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("M/d/y H:m:ss"))
-  private val languageList by lazy { listOf(java, python, kotlin) }
+  private val languageList by lazy { [java, python, kotlin] }
   private val languageMap by lazy { languageList.associateBy { it.languageType } }
 
   // contentMap will prevent reading the same content multiple times
@@ -96,7 +96,7 @@ class ReadingBatContent {
   /** Language group for Kotlin challenges. Accessible in the DSL as a property or block receiver. */
   val kotlin by lazy { LanguageGroup<KotlinChallenge>(this, Kotlin) }
 
-  val languages by lazy { listOf(python, java, kotlin) }
+  val languages by lazy { [python, java, kotlin] }
 
   val cacheChallenges get() = isProduction() || isTesting()
 
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/challenge/Challenge.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/challenge/Challenge.kt
index 46cda8ba6..9e43773df 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/challenge/Challenge.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/challenge/Challenge.kt
@@ -95,7 +95,6 @@ sealed class Challenge(
 
   // Allow description updates only if not found in the Content.kt decl
   private val isDescriptionSetInDsl by lazy { description.isNotBlank() }
-  internal val gitpodUrl by lazy { pathOf(repo.sourcePrefix, "blob/$branchName", srcPath, fqName) }
   internal val parsedDescription by lazy { MarkdownParser.toHtml(description) }
   internal val path by lazy { pathOf(languageName, groupName, challengeName) }
 
@@ -308,7 +307,7 @@ class KotlinChallenge(
     val funcCode = "\n${extractKotlinFunction(lines)}\n\n"
     val invocations = extractKotlinInvocations(lines, KotlinParse.funMainRegex, KotlinParse.kotlinEndRegex)
     val script = convertToKotlinScript(lines).also { logger.debug { "Kotlin: $it" } }
-    val correctAnswers = mutableListOf<Any>()
+    val correctAnswers: MutableList<Any> = []
 
     logger.debug { "$challengeName return type: $returnType script: \n${script.withLineNumbers()}" }
 
@@ -360,7 +359,7 @@ class PythonChallenge(
     val funcCode = extractPythonFunction(lines)
     val invocations = extractPythonInvocations(lines, PythonParse.defMainRegex, PythonParse.ifMainEndRegex)
     val script = convertToPythonScript(lines)
-    val correctAnswers = mutableListOf<Any>()
+    val correctAnswers: MutableList<Any> = []
 
     logger.debug { "$challengeName return type: $returnType script: \n${script.withLineNumbers()}" }
 
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/dsl/parse/JavaParse.kt b/readingbat-core/src/main/kotlin/com/readingbat/dsl/parse/JavaParse.kt
index 1231b91ea..c4aa8a918 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/dsl/parse/JavaParse.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/dsl/parse/JavaParse.kt
@@ -48,15 +48,15 @@ internal object JavaParse {
   internal val svmRegex = Regex("""\s*static\s+void\s+main\(""")
 
   private val prefixRegex =
-    listOf(
+    [
       Regex("""System\.out\.println\("""),
       Regex("""ArrayUtils\.arrayPrint\("""),
       Regex("""ListUtils\.listPrint\("""),
       Regex("""arrayPrint\("""),
       Regex("""listPrint\("""),
-    )
+    ]
   private val prefixes =
-    listOf("System.out.println", "ArrayUtils.arrayPrint", "ListUtils.listPrint", "arrayPrint", "listPrint")
+    ["System.out.println", "ArrayUtils.arrayPrint", "ListUtils.listPrint", "arrayPrint", "listPrint"]
 
   /**
    * Derives the return type of a Java challenge function by locating the first `static` method
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/ChallengePage.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/ChallengePage.kt
index 12cd8a7a0..50c9f8407 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/ChallengePage.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/ChallengePage.kt
@@ -706,11 +706,9 @@ internal object ChallengePage {
     val groupName = challenge.groupName
     val challengeName = challenge.challengeName
 
-    p(classes = TwClasses.EXPERIMENT) {
-      +"Experiment with this code on "
-      this@otherLinks.addLink("Gitpod.io", "https://gitpod.io/#${challenge.gitpodUrl}", true)
-      if (languageType.isKotlin) {
-        +" or as a "
+    if (languageType.isKotlin) {
+      p(classes = TwClasses.EXPERIMENT) {
+        +"Experiment with this code as a "
         this@otherLinks.addLink("Kotlin Playground", pathOf(PLAYGROUND_ROOT, groupName, challengeName), false)
       }
     }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/HelpAndLogin.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/HelpAndLogin.kt
index 8cc3843c2..ea3fa0d3a 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/HelpAndLogin.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/HelpAndLogin.kt
@@ -56,7 +56,7 @@ import kotlinx.html.tr
  * (about, help, admin, prefs), teacher/student mode toggle, and the OAuth sign-in modal.
  */
 internal object HelpAndLogin {
-  private val rootVals = listOf("", "/")
+  private val rootVals = ["", "/"]
 
   // Google "G" logo — official colors, 18x18
   @Suppress("ktlint:standard:max-line-length")
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/LanguageGroupPage.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/LanguageGroupPage.kt
index 098e020fe..a9f43fb52 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/LanguageGroupPage.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/LanguageGroupPage.kt
@@ -124,7 +124,7 @@ internal object LanguageGroupPage {
         head { headDefault() }
 
         body {
-          val oauthError = queryParam(OAUTH_ERROR).takeIf { it in listOf("github", "google") } ?: ""
+          val oauthError = queryParam(OAUTH_ERROR).takeIf { it in ["github", "google"] } ?: ""
           val msg =
             if (oauthError.isNotBlank())
               Message("Sign-in with ${oauthError.toCapitalized()} failed. Please try again.", isError = true)
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/PageUtils.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/PageUtils.kt
index 8b123687c..56c946d3e 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/PageUtils.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/PageUtils.kt
@@ -324,7 +324,7 @@ internal object PageUtils {
 
   fun BODY.displayMessage(msg: Message) = if (msg.isNotBlank) +(msg.toString()) else rawHtml(nbsp.text)
 
-  private val rootVals = listOf("", "/", Java.contentRoot, Python.contentRoot, Kotlin.contentRoot)
+  private val rootVals = ["", "/", Java.contentRoot, Python.contentRoot, Kotlin.contentRoot]
 
   fun BODY.backLink(vararg pathElems: String = arrayOf("/")) {
     if (pathElems.size == 1 && pathElems[0] in rootVals)
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/SessionsPage.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/SessionsPage.kt
index effaf361e..dbbe483a4 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/SessionsPage.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/SessionsPage.kt
@@ -72,13 +72,13 @@ internal object SessionsPage {
           h2 { +"ReadingBat Sessions" }
 
           val activeUserCounts =
-            listOf(
+            [
               1.minutes to "minute",
               15.minutes to "15 minutes",
               1.hours to "hour",
               24.hours to "24 hours",
               7.days to "week",
-            )
+            ]
               .map { (duration, label) -> label to activeSessions(duration) }
 
           h3 { +"Active Users" }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/pages/SystemConfigurationPage.kt b/readingbat-core/src/main/kotlin/com/readingbat/pages/SystemConfigurationPage.kt
index 58c805660..5f9aa4c3c 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/pages/SystemConfigurationPage.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/pages/SystemConfigurationPage.kt
@@ -166,13 +166,13 @@ internal object SystemConfigurationPage {
             h3 { +"System Maps" }
             div(classes = TwClasses.INDENT_1EM) {
               table {
-                listOf(
+                [
                   "Request timing map size" to requestTimingMap,
                   "IP Geo map size" to geoInfoMap,
                   "Content map size" to content.contentMap,
                   "User ID cache size" to userIdCache,
                   "User email cache size" to emailCache,
-                )
+                ]
                   .forEach {
                     tr {
                       td { +it.first }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/posts/ChallengePost.kt b/readingbat-core/src/main/kotlin/com/readingbat/posts/ChallengePost.kt
index 70a02db43..7f9e9d0bc 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/posts/ChallengePost.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/posts/ChallengePost.kt
@@ -130,7 +130,7 @@ data class ChallengeHistory(
   var invocation: Invocation,
   var correct: Boolean = false,
   var incorrectAttempts: Int = 0,
-  @Required val answers: MutableList<String> = mutableListOf(),
+  @Required val answers: MutableList<String> = [],
 ) {
   fun markCorrect(userResponse: String) {
     correct = true
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/ConfigureOAuth.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/ConfigureOAuth.kt
index 73d443bb4..afd83d312 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/ConfigureOAuth.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/ConfigureOAuth.kt
@@ -82,7 +82,7 @@ internal object ConfigureOAuth {
           requestMethod = HttpMethod.Post,
           clientId = clientId,
           clientSecret = clientSecret,
-          defaultScopes = listOf("user:email"),
+          defaultScopes = ["user:email"],
         )
       }
       client = httpClient
@@ -115,7 +115,7 @@ internal object ConfigureOAuth {
           requestMethod = HttpMethod.Post,
           clientId = clientId,
           clientSecret = clientSecret,
-          defaultScopes = listOf("openid", "profile", "email"),
+          defaultScopes = ["openid", "profile", "email"],
         )
       }
       client = httpClient
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/GeoInfo.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/GeoInfo.kt
index 8ba0b09fb..ebf3061b1 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/GeoInfo.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/GeoInfo.kt
@@ -91,7 +91,7 @@ class GeoInfo(val requireDbmsLookUp: Boolean, val dbmsId: Long, val remoteHost:
   fun summary() =
     if (valid)
       try {
-        listOf(city, state_prov, country_name, organization).joinToString(", ")
+        [city, state_prov, country_name, organization].joinToString(", ")
       } catch (_: NoSuchElementException) {
         "Missing Geo data"
       }
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/Installs.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/Installs.kt
index 57734b8ed..9f8bc4c9b 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/Installs.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/Installs.kt
@@ -87,7 +87,7 @@ import kotlin.time.Duration.Companion.seconds
  */
 object Installs {
   private val logger = KotlinLogging.logger {}
-  private val excludedEndpoints = listOf("/$STATIC/", "$WS_ROOT/")
+  private val excludedEndpoints = ["/$STATIC/", "$WS_ROOT/"]
 
   /**
    * Paths excluded from rate limiting: static assets, WebSocket upgrades, and health pings.
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/Intercepts.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/Intercepts.kt
index ab088b408..daf929575 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/Intercepts.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/Intercepts.kt
@@ -123,10 +123,10 @@ internal object Intercepts {
     )
 
   val publicPrefixes =
-    listOf(
+    [
       "$OAUTH_PREFIX/",
       "/$STATIC/",
-    )
+    ]
 
   // Paths that must remain available before the DSL content has finished loading.
   // Anything else gets a 503 + ContentLoadingPage until ReadingBatServer.isContentReady is true.
@@ -139,9 +139,9 @@ internal object Intercepts {
     )
 
   val readinessAllowedPrefixes =
-    listOf(
+    [
       "/$STATIC/",
-    )
+    ]
 
   @Suppress("unused")
   val timer =
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/Locations.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/Locations.kt
index c881402fb..748407fe3 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/Locations.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/Locations.kt
@@ -174,7 +174,7 @@ class PlaygroundRequest(val groupName: String, val challengeName: String)
 /** Inline value class wrapping a language name string (e.g., "java", "python", "kotlin"). */
 @JvmInline
 value class LanguageName(val value: String) {
-  val isJvm get() = value in listOf("kotlin", "java") // jmvLanguages
+  val isJvm get() = value in ["kotlin", "java"] // jmvLanguages
 
   fun toLanguageType() =
     try {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/PostgresTables.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/PostgresTables.kt
index 64b2c9637..4a9d4c39f 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/PostgresTables.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/PostgresTables.kt
@@ -29,22 +29,22 @@ import org.jetbrains.exposed.v1.datetime.timestamp
 
 /** Unique index on (session_ref, user_ref) for the user_sessions table. */
 val userSessionIndex =
-  Index(listOf(UserSessionsTable.sessionRef, UserSessionsTable.userRef), true, "user_sessions_unique")
+  Index([UserSessionsTable.sessionRef, UserSessionsTable.userRef], true, "user_sessions_unique")
 
 val userChallengeInfoIndex =
-  Index(listOf(UserChallengeInfoTable.userRef, UserChallengeInfoTable.md5), true, "user_challenge_info_unique")
+  Index([UserChallengeInfoTable.userRef, UserChallengeInfoTable.md5], true, "user_challenge_info_unique")
 
 val userAnswerHistoryIndex =
   Index(
-    listOf(UserAnswerHistoryTable.userRef, UserAnswerHistoryTable.md5, UserAnswerHistoryTable.invocation),
+    [UserAnswerHistoryTable.userRef, UserAnswerHistoryTable.md5, UserAnswerHistoryTable.invocation],
     true,
     "user_answer_history_unique",
   )
 
 val oauthLinksProviderIndex =
-  Index(listOf(OAuthLinksTable.provider, OAuthLinksTable.providerId), true, "oauth_links_provider_unique")
+  Index([OAuthLinksTable.provider, OAuthLinksTable.providerId], true, "oauth_links_provider_unique")
 
-val geoInfosUnique = Index(listOf(GeoInfosTable.ip), true, "geo_info_unique")
+val geoInfosUnique = Index([GeoInfosTable.ip], true, "geo_info_unique")
 
 /** Tracks anonymous browser sessions identified by a random session ID cookie. */
 object BrowserSessionsTable : LongIdTable("browser_sessions") {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/routes/SysAdminRoutes.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/routes/SysAdminRoutes.kt
index 12ff7bcb6..2cf36f07b 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/routes/SysAdminRoutes.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/routes/SysAdminRoutes.kt
@@ -98,11 +98,11 @@ fun Routing.sysAdminRoutes(metrics: Metrics, resetContentFunc: (String) -> Unit)
         }
     }
 
-    return listOf(
+    return [
       deleteContentDslCache(),
       deleteSourceCodeCache(),
       deleteDirContentsCache(),
-    ).joinToString(", ")
+    ].joinToString(", ")
   }
 
   post(RESET_CONTENT_DSL_ENDPOINT, metrics) {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ChallengeGroupWs.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ChallengeGroupWs.kt
index 12ac19a4f..9a8a8eb3f 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ChallengeGroupWs.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ChallengeGroupWs.kt
@@ -106,7 +106,7 @@ internal object ChallengeGroupWs {
 
               if (enrollees.isNotEmpty()) {
                 // Reorder challenges to return values left to right
-                val ltor = mutableListOf<Challenge>()
+                val ltor: MutableList<Challenge> = []
                 val rows = challenges.size.rows(Constants.COLUMN_CNT)
                 repeat(rows) { i ->
                   challenges
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ClassSummaryWs.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ClassSummaryWs.kt
index 0dbedea91..340da8aac 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ClassSummaryWs.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/ClassSummaryWs.kt
@@ -108,7 +108,7 @@ internal object ClassSummaryWs {
                   for (enrollee in enrollees) {
                     var incorrectAttempts = 0
 
-                    val results = mutableListOf<String>()
+                    val results: MutableList<String> = []
                     for (invocation in funcInfo.invocations) {
                       val historyMd5 = md5Of(langName, groupName, challengeName, invocation)
                       if (enrollee.historyExists(historyMd5, invocation)) {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/PubSubCommandsWs.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/PubSubCommandsWs.kt
index ebd6072f6..e98732a3a 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/PubSubCommandsWs.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/PubSubCommandsWs.kt
@@ -62,10 +62,10 @@ internal object PubSubCommandsWs {
     @Transient val endPoint: String,
     val languageTypes: List<LanguageType>,
   ) {
-    LOAD_JAVA(LOAD_JAVA_ENDPOINT, listOf(Java)),
-    LOAD_PYTHON(LOAD_PYTHON_ENDPOINT, listOf(Python)),
-    LOAD_KOTLIN(LOAD_KOTLIN_ENDPOINT, listOf(Kotlin)),
-    LOAD_ALL(LOAD_ALL_ENDPOINT, listOf(Java, Python, Kotlin)),
+    LOAD_JAVA(LOAD_JAVA_ENDPOINT, [Java]),
+    LOAD_PYTHON(LOAD_PYTHON_ENDPOINT, [Python]),
+    LOAD_KOTLIN(LOAD_KOTLIN_ENDPOINT, [Kotlin]),
+    LOAD_ALL(LOAD_ALL_ENDPOINT, [Java, Python, Kotlin]),
     ;
 
     fun toJson() = Json.encodeToString(serializer(), this)
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/StudentSummaryWs.kt b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/StudentSummaryWs.kt
index 5e319b760..6233107e2 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/server/ws/StudentSummaryWs.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/server/ws/StudentSummaryWs.kt
@@ -106,7 +106,7 @@ internal object StudentSummaryWs {
                   var incorrectAttempts = 0
                   var attempted = 0
 
-                  val results = mutableListOf<String>()
+                  val results: MutableList<String> = []
                   for (invocation in funcInfo.invocations) {
                     val historyMd5 = md5Of(languageName, groupName, challengeName, invocation)
                     if (student.historyExists(historyMd5, invocation)) {
diff --git a/readingbat-core/src/main/kotlin/com/readingbat/utils/ScriptTest.kt b/readingbat-core/src/main/kotlin/com/readingbat/utils/ScriptTest.kt
index ad922fd0e..0a7458309 100644
--- a/readingbat-core/src/main/kotlin/com/readingbat/utils/ScriptTest.kt
+++ b/readingbat-core/src/main/kotlin/com/readingbat/utils/ScriptTest.kt
@@ -52,7 +52,7 @@ fun main() {
 
 @Suppress("unused")
 fun javaTest() {
-  val correctAnswers = mutableListOf<Any>()
+  val correctAnswers: MutableList<Any> = []
   val script =
     """
       public class LessThan {
@@ -97,7 +97,7 @@ fun javaTest() {
 
 @Suppress("unused")
 fun pythonTest() {
-  val correctAnswers = mutableListOf<Any>()
+  val correctAnswers: MutableList<Any> = []
 
   val script =
     """
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerHistoryBulkEquivalenceTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerHistoryBulkEquivalenceTest.kt
index 844f5a13e..b1dabfcda 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerHistoryBulkEquivalenceTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerHistoryBulkEquivalenceTest.kt
@@ -70,7 +70,7 @@ class AnswerHistoryBulkEquivalenceTest : StringSpec() {
           }
         }
 
-        val bulk = user.answerHistoryBulk(listOf("md5-a", "md5-b", "md5-c"))
+        val bulk = user.answerHistoryBulk(["md5-a", "md5-b", "md5-c"])
 
         // Present for exactly the md5s with stored history (== historyExists), absent otherwise.
         bulk.keys shouldBe setOf("md5-a", "md5-b")
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerPublisherTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerPublisherTest.kt
index f8b3384f1..1f5f4118e 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerPublisherTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/common/AnswerPublisherTest.kt
@@ -30,11 +30,11 @@ class AnswerPublisherTest : StringSpec() {
     // The teacher dashboard renders this string via innerHTML over a WebSocket, so student
     // answers must be HTML-escaped to prevent stored XSS, while the <br> separators stay literal.
     "formatDashboardAnswers reverses, limits, and joins answers with <br>" {
-      AnswerPublisher.formatDashboardAnswers(listOf("a", "b", "c"), 2) shouldBe "c<br>b"
+      AnswerPublisher.formatDashboardAnswers(["a", "b", "c"], 2) shouldBe "c<br>b"
     }
 
     "formatDashboardAnswers leaves a plain answer unchanged" {
-      AnswerPublisher.formatDashboardAnswers(listOf("42"), 10) shouldBe "42"
+      AnswerPublisher.formatDashboardAnswers(["42"], 10) shouldBe "42"
     }
 
     "formatDashboardAnswers returns empty string for no answers" {
@@ -42,13 +42,13 @@ class AnswerPublisherTest : StringSpec() {
     }
 
     "formatDashboardAnswers HTML-escapes a script-injection answer" {
-      val result = AnswerPublisher.formatDashboardAnswers(listOf("<img src=x onerror=alert(1)>"), 10)
+      val result = AnswerPublisher.formatDashboardAnswers(["<img src=x onerror=alert(1)>"], 10)
       result shouldNotContainSubstring "<img"
       result shouldContainSubstring "&lt;img"
     }
 
     "formatDashboardAnswers keeps the <br> separator literal between escaped answers" {
-      val result = AnswerPublisher.formatDashboardAnswers(listOf("<b>x", "<b>y"), 10)
+      val result = AnswerPublisher.formatDashboardAnswers(["<b>x", "<b>y"], 10)
       result shouldBe "&lt;b&gt;y<br>&lt;b&gt;x"
     }
 
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/common/PythonListTokenizerTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/common/PythonListTokenizerTest.kt
index ff7611d56..4e1c1325b 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/common/PythonListTokenizerTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/common/PythonListTokenizerTest.kt
@@ -30,15 +30,15 @@ import io.kotest.matchers.shouldBe
 class PythonListTokenizerTest : StringSpec() {
   init {
     "splitTopLevelCommas keeps commas inside single-quoted elements together" {
-      splitTopLevelCommas("'a,b', 'c'").map { it.trim() } shouldBe listOf("'a,b'", "'c'")
+      splitTopLevelCommas("'a,b', 'c'").map { it.trim() } shouldBe ["'a,b'", "'c'"]
     }
 
     "splitTopLevelCommas keeps commas inside double-quoted elements together" {
-      splitTopLevelCommas(""""a,b", "c"""").map { it.trim() } shouldBe listOf("\"a,b\"", "\"c\"")
+      splitTopLevelCommas(""""a,b", "c"""").map { it.trim() } shouldBe ["\"a,b\"", "\"c\""]
     }
 
     "splitTopLevelCommas splits unquoted top-level elements" {
-      splitTopLevelCommas("1, 2, 3").map { it.trim() } shouldBe listOf("1", "2", "3")
+      splitTopLevelCommas("1, 2, 3").map { it.trim() } shouldBe ["1", "2", "3"]
     }
 
     "splitTopLevelCommas returns an empty list for blank input" {
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/dsl/DirCacheTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/dsl/DirCacheTest.kt
index e5c164496..fa7600e1f 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/dsl/DirCacheTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/dsl/DirCacheTest.kt
@@ -30,14 +30,14 @@ import io.kotest.matchers.shouldBe
 class DirCacheTest : StringSpec() {
   init {
     "readDirCache returns what writeDirCache stored under a consistent key" {
-      ChallengeGroup.writeDirCache("java/Warmup-1", listOf("a.java", "b.java"))
-      ChallengeGroup.readDirCache("java/Warmup-1") shouldBe listOf("a.java", "b.java")
+      ChallengeGroup.writeDirCache("java/Warmup-1", ["a.java", "b.java"])
+      ChallengeGroup.readDirCache("java/Warmup-1") shouldBe ["a.java", "b.java"]
     }
 
     "rewriting the dir cache overwrites instead of accumulating duplicates" {
-      ChallengeGroup.writeDirCache("python/Group-2", listOf("a.py"))
-      ChallengeGroup.writeDirCache("python/Group-2", listOf("a.py", "b.py"))
-      ChallengeGroup.readDirCache("python/Group-2") shouldBe listOf("a.py", "b.py")
+      ChallengeGroup.writeDirCache("python/Group-2", ["a.py"])
+      ChallengeGroup.writeDirCache("python/Group-2", ["a.py", "b.py"])
+      ChallengeGroup.readDirCache("python/Group-2") shouldBe ["a.py", "b.py"]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/dsl/IndicesFilterTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/dsl/IndicesFilterTest.kt
index 9bb6718dd..5a04af5e0 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/dsl/IndicesFilterTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/dsl/IndicesFilterTest.kt
@@ -29,7 +29,7 @@ class IndicesFilterTest : StringSpec() {
   init {
     "extractJavaFunction should find static method body" {
       val code =
-        listOf(
+        [
           "import java.util.*;",
           "",
           "public class Warmup {",
@@ -41,7 +41,7 @@ class IndicesFilterTest : StringSpec() {
           "    System.out.println(sleepIn(false, false));",
           "  }",
           "}",
-        )
+        ]
       val result = extractJavaFunction(ChallengeName("sleepIn"), code)
       result shouldContain "sleepIn"
       result shouldContain "return !weekday || vacation"
@@ -50,13 +50,13 @@ class IndicesFilterTest : StringSpec() {
 
     "extractPythonFunction should find def function body" {
       val code =
-        listOf(
+        [
           "def sleep_in(weekday, vacation):",
           "  return not weekday or vacation",
           "",
           "def main():",
           "  print(sleep_in(False, False))",
-        )
+        ]
       val result = extractPythonFunction(code)
       result shouldContain "sleep_in"
       result shouldContain "return not weekday or vacation"
@@ -64,7 +64,7 @@ class IndicesFilterTest : StringSpec() {
     }
 
     "indices.filter produces same results as mapIndexed for index extraction" {
-      val items = listOf("apple", "banana", "avocado", "cherry", "apricot")
+      val items = ["apple", "banana", "avocado", "cherry", "apricot"]
       val pattern = Regex("^a")
 
       val viaMapIndexed =
@@ -75,7 +75,7 @@ class IndicesFilterTest : StringSpec() {
       val viaIndicesFilter = items.indices.filter { items[it].contains(pattern) }
 
       viaIndicesFilter shouldBe viaMapIndexed
-      viaIndicesFilter shouldBe listOf(0, 2, 4)
+      viaIndicesFilter shouldBe [0, 2, 4]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/dsl/InvokesTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/dsl/InvokesTest.kt
index c0d65cfe1..896e268cf 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/dsl/InvokesTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/dsl/InvokesTest.kt
@@ -50,7 +50,7 @@ class InvokesTest : StringSpec() {
         """.trimIndent()
 
       extractPythonInvocations(s, defMainRegex, ifMainEndRegex).map { it.toString() } shouldBe
-        listOf("simple_choice2(True, True)", "simple_choice2(True, False)")
+        ["simple_choice2(True, True)", "simple_choice2(True, False)"]
     }
 
     "javaInvokesTest" {
@@ -78,10 +78,10 @@ class InvokesTest : StringSpec() {
         """.trimIndent()
 
       extractJavaInvocations(s, psvmRegex, javaEndRegex).map { it.toString() } shouldBe
-        listOf(
+        [
           """joinEnds("Blue zebra")""",
           """joinEnds("Tree")""",
-        )
+        ]
     }
 
     "kotlinInvokesTest" {
@@ -98,10 +98,10 @@ class InvokesTest : StringSpec() {
         """.trimIndent()
 
       extractKotlinInvocations(s, funMainRegex, kotlinEndRegex).map { it.toString() } shouldBe
-        listOf(
+        [
           """listOf("a").combine2()""",
           """listOf("a", "b", "c", "d").combine2()""",
-        )
+        ]
     }
 
     "classImportTest" {
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/dsl/JavaInvocationOrderTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/dsl/JavaInvocationOrderTest.kt
index ce60c8c23..b8a2d5f0f 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/dsl/JavaInvocationOrderTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/dsl/JavaInvocationOrderTest.kt
@@ -44,7 +44,7 @@ class JavaInvocationOrderTest : StringSpec() {
         """.trimIndent()
 
       extractJavaInvocations(code, psvmRegex, javaEndRegex).map { it.toString() } shouldBe
-        listOf("a(1)", "b(2)", "c(3)")
+        ["a(1)", "b(2)", "c(3)"]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/dsl/StripLeadingCommentsTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/dsl/StripLeadingCommentsTest.kt
index 4be60b18b..cd8befc5c 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/dsl/StripLeadingCommentsTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/dsl/StripLeadingCommentsTest.kt
@@ -25,88 +25,88 @@ class StripLeadingCommentsTest : StringSpec() {
   init {
     "strips multi-line copyright block comment" {
       val lines =
-        listOf(
+        [
         "/*",
         " * Copyright © 2023 Paul Ambrose",
         " */",
         "",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "keeps non-copyright multi-line block comment" {
       val lines =
-        listOf(
+        [
         "/* This is a regular comment */",
         "fun hello() = 1",
-      )
+      ]
       stripLeadingComments(lines) shouldBe lines
     }
 
     "strips single-line copyright block comment" {
       val lines =
-        listOf(
+        [
         "/* Copyright 2023 */",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "strips copyright line comment" {
       val lines =
-        listOf(
+        [
         "// Copyright 2023",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "keeps non-copyright line comment" {
       val lines =
-        listOf(
+        [
         "// This is a regular comment",
         "fun hello() = 1",
-      )
+      ]
       stripLeadingComments(lines) shouldBe lines
     }
 
     "strips leading blank lines before code" {
       val lines =
-        listOf(
+        [
         "",
         "",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "strips copyright block followed by blank lines" {
       val lines =
-        listOf(
+        [
         "/*",
         " * Copyright © 2023",
         " */",
         "",
         "",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "keeps non-copyright block comment after copyright block" {
       val lines =
-        listOf(
+        [
         "/* Copyright 2023 */",
         "",
         "/* This describes the function */",
         "fun hello() = 1",
-      )
+      ]
       stripLeadingComments(lines) shouldBe
-        listOf(
+        [
         "/* This describes the function */",
         "fun hello() = 1",
-      )
+      ]
     }
 
     "handles empty input" {
@@ -114,45 +114,45 @@ class StripLeadingCommentsTest : StringSpec() {
     }
 
     "handles all-blank input" {
-      stripLeadingComments(listOf("", "  ", "")) shouldBe emptyList()
+      stripLeadingComments(["", "  ", ""]) shouldBe emptyList()
     }
 
     "copyright check is case-insensitive" {
       val lines =
-        listOf(
+        [
         "/* cOpYrIgHt 2023 */",
         "fun hello() = 1",
-      )
-      stripLeadingComments(lines) shouldBe listOf("fun hello() = 1")
+      ]
+      stripLeadingComments(lines) shouldBe ["fun hello() = 1"]
     }
 
     "keeps multi-line non-copyright block comment" {
       val lines =
-        listOf(
+        [
         "/*",
         " * This is a doc comment",
         " */",
         "fun hello() = 1",
-      )
+      ]
       stripLeadingComments(lines) shouldBe lines
     }
 
     "handles unclosed multi-line copyright block at end of input" {
       val lines =
-        listOf(
+        [
         "/*",
         " * Copyright 2023",
-      )
+      ]
       // The block never closes, but all lines contain copyright — should strip them
       stripLeadingComments(lines) shouldBe emptyList()
     }
 
     "handles code with no leading comments" {
       val lines =
-        listOf(
+        [
         "fun hello() = 1",
         "fun world() = 2",
-      )
+      ]
       stripLeadingComments(lines) shouldBe lines
     }
   }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/posts/AnswerHistoryPersistenceTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/posts/AnswerHistoryPersistenceTest.kt
index 3de209f24..73283618d 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/posts/AnswerHistoryPersistenceTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/posts/AnswerHistoryPersistenceTest.kt
@@ -79,7 +79,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
               row[UserAnswerHistoryTable.invocation] = invocation.value
               row[correct] = true
               row[incorrectAttempts] = 2
-              row[historyJson] = Json.encodeToString(listOf("wrong1", "wrong2", "right"))
+              row[historyJson] = Json.encodeToString(["wrong1", "wrong2", "right"])
             }
           }
         }
@@ -88,7 +88,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
         val history = user.answerHistory(md5, invocation)
         history.correct shouldBe true
         history.incorrectAttempts shouldBe 2
-        history.answers shouldContainExactly listOf("wrong1", "wrong2", "right")
+        history.answers shouldContainExactly ["wrong1", "wrong2", "right"]
       }
     }
 
@@ -149,7 +149,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
               row[invocation] = "invokeA()"
               row[correct] = true
               row[incorrectAttempts] = 0
-              row[historyJson] = Json.encodeToString(listOf("answerA"))
+              row[historyJson] = Json.encodeToString(["answerA"])
             }
             upsert(conflictIndex = userAnswerHistoryIndex) { row ->
               row[userRef] = user.userDbmsId
@@ -158,12 +158,12 @@ class AnswerHistoryPersistenceTest : StringSpec() {
               row[invocation] = "invokeB()"
               row[correct] = false
               row[incorrectAttempts] = 3
-              row[historyJson] = Json.encodeToString(listOf("wrong1", "wrong2", "wrong3"))
+              row[historyJson] = Json.encodeToString(["wrong1", "wrong2", "wrong3"])
             }
           }
         }
 
-        val bulk = user.answerHistoryBulk(listOf(md5A, md5B, md5Missing))
+        val bulk = user.answerHistoryBulk([md5A, md5B, md5Missing])
         bulk.size shouldBe 2
         bulk[md5A]!!.correct shouldBe true
         bulk[md5B]!!.incorrectAttempts shouldBe 3
@@ -195,7 +195,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
               row[UserAnswerHistoryTable.invocation] = invocation.value
               row[correct] = false
               row[incorrectAttempts] = 1
-              row[historyJson] = Json.encodeToString(listOf("wrong"))
+              row[historyJson] = Json.encodeToString(["wrong"])
             }
           }
         }
@@ -212,7 +212,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
               row[UserAnswerHistoryTable.invocation] = invocation.value
               row[correct] = true
               row[incorrectAttempts] = 1
-              row[historyJson] = Json.encodeToString(listOf("wrong", "right"))
+              row[historyJson] = Json.encodeToString(["wrong", "right"])
             }
           }
         }
@@ -220,7 +220,7 @@ class AnswerHistoryPersistenceTest : StringSpec() {
         val updated = user.answerHistory(md5, invocation)
         updated.correct shouldBe true
         updated.incorrectAttempts shouldBe 1
-        updated.answers shouldContainExactly listOf("wrong", "right")
+        updated.answers shouldContainExactly ["wrong", "right"]
       }
     }
 
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/posts/BoundedResponsesTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/posts/BoundedResponsesTest.kt
index dc9dc7b7d..b49abfb8b 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/posts/BoundedResponsesTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/posts/BoundedResponsesTest.kt
@@ -31,24 +31,24 @@ class BoundedResponsesTest : StringSpec() {
   init {
     "boundedResponses returns one trimmed response per invocation" {
       ChallengePost.boundedResponses(2, mapOf("response0" to " a ", "response1" to "b")) shouldBe
-        listOf("a", "b")
+        ["a", "b"]
     }
 
     "boundedResponses ignores extra response params instead of throwing" {
       ChallengePost.boundedResponses(
         2,
         mapOf("response0" to "a", "response1" to "b", "response2" to "c", "response3" to "d"),
-      ) shouldBe listOf("a", "b")
+      ) shouldBe ["a", "b"]
     }
 
     "boundedResponses treats a missing response as blank (unanswered)" {
       ChallengePost.boundedResponses(3, mapOf("response0" to "a", "response2" to "c")) shouldBe
-        listOf("a", "", "c")
+        ["a", "", "c"]
     }
 
     "boundedResponses ignores non-numeric response keys" {
       ChallengePost.boundedResponses(1, mapOf("response0" to "a", "responseFoo" to "x")) shouldBe
-        listOf("a")
+        ["a"]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/posts/BulkAnswerHistoryTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/posts/BulkAnswerHistoryTest.kt
index 75491055b..b09412d10 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/posts/BulkAnswerHistoryTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/posts/BulkAnswerHistoryTest.kt
@@ -34,7 +34,7 @@ class BulkAnswerHistoryTest : StringSpec() {
     }
 
     "ChallengeHistory with data preserves all fields" {
-      val answers = mutableListOf("wrong1", "wrong2", "correct")
+      val answers: MutableList<String> = ["wrong1", "wrong2", "correct"]
       val history =
         ChallengeHistory(
           invocation = Invocation("foo(2)"),
@@ -44,7 +44,7 @@ class BulkAnswerHistoryTest : StringSpec() {
         )
       history.correct shouldBe true
       history.incorrectAttempts shouldBe 2
-      history.answers shouldContainExactly listOf("wrong1", "wrong2", "correct")
+      history.answers shouldContainExactly ["wrong1", "wrong2", "correct"]
     }
 
     "Bulk result map lookup falls back to default for missing md5" {
@@ -55,13 +55,13 @@ class BulkAnswerHistoryTest : StringSpec() {
               invocation = Invocation("test(1)"),
               correct = true,
               incorrectAttempts = 0,
-              answers = mutableListOf("42"),
+              answers = ["42"],
             ),
         )
 
       val found = historyMap["abc123"] ?: ChallengeHistory(Invocation("test(1)"))
       found.correct shouldBe true
-      found.answers shouldContainExactly listOf("42")
+      found.answers shouldContainExactly ["42"]
 
       val missing = historyMap["xyz789"] ?: ChallengeHistory(Invocation("test(2)"))
       missing.correct shouldBe false
@@ -72,17 +72,17 @@ class BulkAnswerHistoryTest : StringSpec() {
     "Multiple invocations map to distinct entries" {
       val historyMap =
         mapOf(
-          "md5_1" to ChallengeHistory(Invocation("foo(1)"), true, 0, mutableListOf("1")),
-          "md5_2" to ChallengeHistory(Invocation("foo(2)"), false, 3, mutableListOf("a", "b", "c")),
-          "md5_3" to ChallengeHistory(Invocation("foo(3)"), true, 1, mutableListOf("x", "3")),
+          "md5_1" to ChallengeHistory(Invocation("foo(1)"), true, 0, ["1"]),
+          "md5_2" to ChallengeHistory(Invocation("foo(2)"), false, 3, ["a", "b", "c"]),
+          "md5_3" to ChallengeHistory(Invocation("foo(3)"), true, 1, ["x", "3"]),
         )
 
       val invocations =
-        listOf(
+        [
           Invocation("foo(1)") to "md5_1",
           Invocation("foo(2)") to "md5_2",
           Invocation("foo(3)") to "md5_3",
-        )
+        ]
 
       var numCorrect = 0
       val results =
@@ -96,12 +96,12 @@ class BulkAnswerHistoryTest : StringSpec() {
       results.size shouldBe 3
       results[0].second.correct shouldBe true
       results[1].second.incorrectAttempts shouldBe 3
-      results[2].second.answers shouldContainExactly listOf("x", "3")
+      results[2].second.answers shouldContainExactly ["x", "3"]
     }
 
     "Empty history map returns defaults for all invocations" {
       val emptyMap = emptyMap<String, ChallengeHistory>()
-      val invocations = listOf("md5_a", "md5_b", "md5_c")
+      val invocations = ["md5_a", "md5_b", "md5_c"]
 
       val results =
         invocations.map { md5 ->
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/posts/ChallengeHistoryTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/posts/ChallengeHistoryTest.kt
index 51b7a28e2..ed5a55f8f 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/posts/ChallengeHistoryTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/posts/ChallengeHistoryTest.kt
@@ -32,7 +32,7 @@ class ChallengeHistoryTest : StringSpec() {
       history.markCorrect("42")
 
       history.correct shouldBe true
-      history.answers shouldContainExactly listOf("42")
+      history.answers shouldContainExactly ["42"]
       history.incorrectAttempts shouldBe 0
     }
 
@@ -43,7 +43,7 @@ class ChallengeHistoryTest : StringSpec() {
 
       history.correct shouldBe false
       history.incorrectAttempts shouldBe 1
-      history.answers shouldContainExactly listOf("wrong")
+      history.answers shouldContainExactly ["wrong"]
     }
 
     "markUnanswered sets correct to false" {
@@ -61,7 +61,7 @@ class ChallengeHistoryTest : StringSpec() {
       history.markIncorrect("wrong")
       history.markIncorrect("wrong")
 
-      history.answers shouldContainExactly listOf("wrong")
+      history.answers shouldContainExactly ["wrong"]
       history.incorrectAttempts shouldBe 1
     }
 
@@ -72,7 +72,7 @@ class ChallengeHistoryTest : StringSpec() {
       history.markIncorrect("second")
       history.markCorrect("correct")
 
-      history.answers shouldContainExactly listOf("first", "second", "correct")
+      history.answers shouldContainExactly ["first", "second", "correct"]
       history.incorrectAttempts shouldBe 2
       history.correct shouldBe true
     }
@@ -93,17 +93,17 @@ class ChallengeHistoryTest : StringSpec() {
     "pre-fetched histories produce correct marking results" {
       // Simulate the pre-fetch pattern: create histories first, then mark them
       val invocations =
-        listOf(
+        [
           Invocation("test(1)"),
           Invocation("test(2)"),
           Invocation("test(3)"),
-        )
+        ]
       val results =
-        listOf(
+        [
           ChallengeResults(invocations[0], userResponse = "42", answered = true, correct = true),
           ChallengeResults(invocations[1], userResponse = "wrong", answered = true, correct = false),
           ChallengeResults(invocations[2], userResponse = "", answered = false, correct = false),
-        )
+        ]
 
       // Pre-fetch: create histories before processing (simulates reading from DB before write tx)
       val histories = invocations.map { ChallengeHistory(it) }
@@ -119,11 +119,11 @@ class ChallengeHistoryTest : StringSpec() {
 
       // Verify results
       histories[0].correct shouldBe true
-      histories[0].answers shouldContainExactly listOf("42")
+      histories[0].answers shouldContainExactly ["42"]
       histories[0].incorrectAttempts shouldBe 0
 
       histories[1].correct shouldBe false
-      histories[1].answers shouldContainExactly listOf("wrong")
+      histories[1].answers shouldContainExactly ["wrong"]
       histories[1].incorrectAttempts shouldBe 1
 
       histories[2].correct shouldBe false
@@ -137,7 +137,7 @@ class ChallengeHistoryTest : StringSpec() {
           invocation = Invocation("test(1)"),
           correct = false,
           incorrectAttempts = 2,
-          answers = mutableListOf("attempt1", "attempt2"),
+          answers = ["attempt1", "attempt2"],
         )
 
       // User now submits the correct answer
@@ -145,7 +145,7 @@ class ChallengeHistoryTest : StringSpec() {
 
       history.correct shouldBe true
       history.incorrectAttempts shouldBe 2 // unchanged
-      history.answers shouldContainExactly listOf("attempt1", "attempt2", "correct_answer")
+      history.answers shouldContainExactly ["attempt1", "attempt2", "correct_answer"]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/posts/UserAnswerQueueTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/posts/UserAnswerQueueTest.kt
index 026a2db25..1b3d394ea 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/posts/UserAnswerQueueTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/posts/UserAnswerQueueTest.kt
@@ -45,7 +45,7 @@ class UserAnswerQueueTest : StringSpec() {
     }
 
     "workerIndex handles negative ids without going out of range" {
-      listOf(-1L, -17L, -1234L).forEach { id ->
+      [-1L, -17L, -1234L].forEach { id ->
         workerIndex(id) shouldBeGreaterThanOrEqual 0
         workerIndex(id) shouldBeLessThan WORKER_COUNT
       }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/AuthorizationCheckTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/AuthorizationCheckTest.kt
index 1a8e56b68..4db450afc 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/AuthorizationCheckTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/AuthorizationCheckTest.kt
@@ -62,13 +62,13 @@ class AuthorizationCheckTest : StringSpec() {
                 .post(CLEAR_CHALLENGE_ANSWERS_ENDPOINT) {
                   header(ContentType, FormUrlEncoded.toString())
                   setBody(
-                    listOf(
+                    [
                       LANGUAGE_NAME_PARAM to "Java",
                       GROUP_NAME_PARAM to TestData.GROUP_NAME,
                       CHALLENGE_NAME_PARAM to "StringArrayTest1",
                       CORRECT_ANSWERS_PARAM to spoofedKey,
                       CHALLENGE_ANSWERS_PARAM to "",
-                    ).formUrlEncode(),
+                    ].formUrlEncode(),
                   )
                 }
             // Should redirect (not crash) — the spoofed key is silently ignored
@@ -92,12 +92,12 @@ class AuthorizationCheckTest : StringSpec() {
                 .post(CLEAR_GROUP_ANSWERS_ENDPOINT) {
                   header(ContentType, FormUrlEncoded.toString())
                   setBody(
-                    listOf(
+                    [
                       LANGUAGE_NAME_PARAM to "Java",
                       GROUP_NAME_PARAM to TestData.GROUP_NAME,
                       CORRECT_ANSWERS_PARAM to "[\"$spoofedKey\"]",
                       CHALLENGE_ANSWERS_PARAM to "[]",
-                    ).formUrlEncode(),
+                    ].formUrlEncode(),
                   )
                 }
             // Should redirect (not crash) — the spoofed keys are silently ignored
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/DeleteFromTableTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/DeleteFromTableTest.kt
index 4dff5c1dd..cbaaf97c7 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/DeleteFromTableTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/DeleteFromTableTest.kt
@@ -63,13 +63,13 @@ class DeleteFromTableTest : StringSpec() {
                 .post(CLEAR_CHALLENGE_ANSWERS_ENDPOINT) {
                   header(ContentType, FormUrlEncoded.toString())
                   setBody(
-                    listOf(
+                    [
                       LANGUAGE_NAME_PARAM to "Java",
                       GROUP_NAME_PARAM to TestData.GROUP_NAME,
                       CHALLENGE_NAME_PARAM to "StringArrayTest1",
                       CORRECT_ANSWERS_PARAM to correctKey,
                       CHALLENGE_ANSWERS_PARAM to challengeKey,
-                    ).formUrlEncode(),
+                    ].formUrlEncode(),
                   )
                 }
             response shouldHaveStatus Found
@@ -90,13 +90,13 @@ class DeleteFromTableTest : StringSpec() {
                 .post(CLEAR_CHALLENGE_ANSWERS_ENDPOINT) {
                   header(ContentType, FormUrlEncoded.toString())
                   setBody(
-                    listOf(
+                    [
                       LANGUAGE_NAME_PARAM to "Java",
                       GROUP_NAME_PARAM to TestData.GROUP_NAME,
                       CHALLENGE_NAME_PARAM to "StringArrayTest1",
                       CORRECT_ANSWERS_PARAM to "",
                       CHALLENGE_ANSWERS_PARAM to "",
-                    ).formUrlEncode(),
+                    ].formUrlEncode(),
                   )
                 }
             response shouldHaveStatus Found
@@ -117,13 +117,13 @@ class DeleteFromTableTest : StringSpec() {
                 .post(CLEAR_CHALLENGE_ANSWERS_ENDPOINT) {
                   header(ContentType, FormUrlEncoded.toString())
                   setBody(
-                    listOf(
+                    [
                       LANGUAGE_NAME_PARAM to "Java",
                       GROUP_NAME_PARAM to TestData.GROUP_NAME,
                       CHALLENGE_NAME_PARAM to "StringArrayTest1",
                       CORRECT_ANSWERS_PARAM to "malformed-key-no-separators",
                       CHALLENGE_ANSWERS_PARAM to "also-malformed",
-                    ).formUrlEncode(),
+                    ].formUrlEncode(),
                   )
                 }
             response shouldHaveStatus Found
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/SerializableTransactionTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/SerializableTransactionTest.kt
index 0c4fa64c4..ef1f9da01 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/SerializableTransactionTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/SerializableTransactionTest.kt
@@ -40,7 +40,7 @@ class SerializableTransactionTest : StringSpec() {
         invocation = Invocation("test()"),
         correct = false,
         incorrectAttempts = 3,
-        answers = mutableListOf("wrong1", "wrong2", "wrong3"),
+        answers = ["wrong1", "wrong2", "wrong3"],
       )
 
       history.markCorrect("right")
@@ -55,13 +55,13 @@ class SerializableTransactionTest : StringSpec() {
         invocation = Invocation("test()"),
         correct = false,
         incorrectAttempts = 2,
-        answers = mutableListOf("wrong1", "wrong2"),
+        answers = ["wrong1", "wrong2"],
       )
 
       history.markIncorrect("wrong3")
       history.correct shouldBe false
       history.incorrectAttempts shouldBe 3
-      history.answers shouldBe mutableListOf("wrong1", "wrong2", "wrong3")
+      history.answers shouldBe ["wrong1", "wrong2", "wrong3"]
     }
 
     "ChallengeHistory markIncorrect does not increment for duplicate answer" {
@@ -70,12 +70,12 @@ class SerializableTransactionTest : StringSpec() {
         invocation = Invocation("test()"),
         correct = false,
         incorrectAttempts = 1,
-        answers = mutableListOf("wrong1"),
+        answers = ["wrong1"],
       )
 
       history.markIncorrect("wrong1")
       history.incorrectAttempts shouldBe 1
-      history.answers shouldBe mutableListOf("wrong1")
+      history.answers shouldBe ["wrong1"]
     }
 
     "ChallengeHistory concurrent mutation scenario shows why isolation matters" {
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/routes/OAuthGitHubEmailTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/routes/OAuthGitHubEmailTest.kt
index c01834cc5..a2915fbd8 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/routes/OAuthGitHubEmailTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/routes/OAuthGitHubEmailTest.kt
@@ -33,24 +33,24 @@ class OAuthGitHubEmailTest : StringSpec() {
 
     "resolveGitHubEmail prefers a primary verified email when the profile email is blank" {
       val emails =
-        listOf(
+        [
           GitHubEmail("secondary@example.com", primary = false, verified = true),
           GitHubEmail("primary@example.com", primary = true, verified = true),
-        )
+        ]
       resolveGitHubEmail(null, emails) shouldBe "primary@example.com"
     }
 
     "resolveGitHubEmail falls back to any verified email" {
       val emails =
-        listOf(
+        [
           GitHubEmail("unverified@example.com", primary = true, verified = false),
           GitHubEmail("verified@example.com", primary = false, verified = true),
-        )
+        ]
       resolveGitHubEmail(null, emails) shouldBe "verified@example.com"
     }
 
     "resolveGitHubEmail returns null when only unverified emails exist" {
-      resolveGitHubEmail(null, listOf(GitHubEmail("x@example.com", primary = true, verified = false))) shouldBe null
+      resolveGitHubEmail(null, [GitHubEmail("x@example.com", primary = true, verified = false)]) shouldBe null
     }
 
     "resolveGitHubEmail returns null when there is no email at all" {
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsConnectionSnapshotTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsConnectionSnapshotTest.kt
index ed053703d..192e73166 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsConnectionSnapshotTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsConnectionSnapshotTest.kt
@@ -47,11 +47,11 @@ class WsConnectionSnapshotTest : StringSpec() {
     }
 
     "snapshotUnderMonitor returns a decoupled copy" {
-      val set = Collections.synchronizedSet(LinkedHashSet<Int>()).apply { addAll(listOf(1, 2, 3)) }
+      val set = Collections.synchronizedSet(LinkedHashSet<Int>()).apply { addAll([1, 2, 3]) }
       val snapshot = set.snapshotUnderMonitor()
       set.add(4)
       set.remove(1)
-      snapshot shouldBe listOf(1, 2, 3)
+      snapshot shouldBe [1, 2, 3]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsProtocolConstantsTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsProtocolConstantsTest.kt
index 0bc5fc9c1..d65f38dc9 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsProtocolConstantsTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/server/ws/WsProtocolConstantsTest.kt
@@ -83,7 +83,7 @@ class WsProtocolConstantsTest : StringSpec() {
         ClassSummary(
         userId = "user1",
         challengeName = "hello",
-        results = listOf("Y", "N"),
+        results = ["Y", "N"],
         stats = "1/2",
         likeDislike = "",
       )
@@ -102,7 +102,7 @@ class WsProtocolConstantsTest : StringSpec() {
         StudentSummary(
         groupName = "Warmup-1",
         challengeName = "hello",
-        results = listOf("Y"),
+        results = ["Y"],
         stats = "1/1",
         likeDislike = "",
       )
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/testcontent/StringListKtTest1.kt b/readingbat-core/src/test/kotlin/com/readingbat/testcontent/StringListKtTest1.kt
index d1b0ca174..8610e5834 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/testcontent/StringListKtTest1.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/testcontent/StringListKtTest1.kt
@@ -17,7 +17,7 @@
 
 package com.readingbat.testcontent
 
-fun combinel(s1: String, s2: String): List<String> = listOf(s1, s2)
+fun combinel(s1: String, s2: String): List<String> = [s1, s2]
 
 fun main() {
   println(combinel("Car", "wash"))
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/utils/ChanceSelectionTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/utils/ChanceSelectionTest.kt
index 442265801..c7916ab2c 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/utils/ChanceSelectionTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/utils/ChanceSelectionTest.kt
@@ -58,7 +58,7 @@ class ChanceSelectionTest : StringSpec() {
       val size = 5
       val current = 2
       val candidates = (0 until size).filter { it != current }
-      candidates shouldBe listOf(0, 1, 3, 4)
+      candidates shouldBe [0, 1, 3, 4]
     }
   }
 }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/utils/ForEachConsistencyTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/utils/ForEachConsistencyTest.kt
index 184b5ad74..136bbead8 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/utils/ForEachConsistencyTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/utils/ForEachConsistencyTest.kt
@@ -23,12 +23,12 @@ import io.kotest.matchers.shouldBe
 class ForEachConsistencyTest : StringSpec() {
   init {
     "forEach with destructuring should process all pairs" {
-      val pairs = listOf("a" to 1, "b" to 2, "c" to 3)
-      val collected = mutableListOf<String>()
+      val pairs = ["a" to 1, "b" to 2, "c" to 3]
+      val collected: MutableList<String> = []
       pairs.forEach { (key, value) ->
         collected += "$key=$value"
       }
-      collected shouldBe listOf("a=1", "b=2", "c=3")
+      collected shouldBe ["a=1", "b=2", "c=3"]
     }
 
     "forEach with destructuring on empty list should be no-op" {
@@ -42,7 +42,7 @@ class ForEachConsistencyTest : StringSpec() {
 
     "forEach with destructuring should maintain order" {
       val pairs = (1..100).map { "key$it" to it }
-      val indices = mutableListOf<Int>()
+      val indices: MutableList<Int> = []
       pairs.forEach { (_, value) ->
         indices += value
       }
diff --git a/readingbat-core/src/test/kotlin/com/readingbat/utils/JsonUtilsTest.kt b/readingbat-core/src/test/kotlin/com/readingbat/utils/JsonUtilsTest.kt
index de75b66e6..37daa00c9 100644
--- a/readingbat-core/src/test/kotlin/com/readingbat/utils/JsonUtilsTest.kt
+++ b/readingbat-core/src/test/kotlin/com/readingbat/utils/JsonUtilsTest.kt
@@ -47,7 +47,7 @@ class JsonUtilsTest : StringSpec() {
     }
 
     "toJson serializes a list of primitives" {
-      listOf(1, 2, 3).toJson() shouldBe "[1,2,3]"
+      [1, 2, 3].toJson() shouldBe "[1,2,3]"
     }
 
     "toJson serializes a map with string keys" {
@@ -56,7 +56,7 @@ class JsonUtilsTest : StringSpec() {
     }
 
     "toJson serializes a nested data class round-trips through Json.decodeFromString" {
-      val original = Wrapper(tag = "t", values = listOf(1, 2, 3), person = Person("Bob", 7))
+      val original = Wrapper(tag = "t", values = [1, 2, 3], person = Person("Bob", 7))
       val encoded = original.toJson()
       Json.decodeFromString<Wrapper>(encoded) shouldBe original
     }
diff --git a/readingbat-kotest/src/main/kotlin/com/readingbat/kotest/TestSupport.kt b/readingbat-kotest/src/main/kotlin/com/readingbat/kotest/TestSupport.kt
index 848a361a8..6e61e30fc 100644
--- a/readingbat-kotest/src/main/kotlin/com/readingbat/kotest/TestSupport.kt
+++ b/readingbat-kotest/src/main/kotlin/com/readingbat/kotest/TestSupport.kt
@@ -91,12 +91,12 @@ object TestSupport {
       functionInfo().block()
     }
 
-  private fun Challenge.formData() =
-    mutableListOf(
+  private fun Challenge.formData(): MutableList<Pair<String, String>> =
+    [
       LANG_SRC to challengeGroup.languageGroup.languageName.value,
       GROUP_SRC to challengeGroup.groupName.value,
       CHALLENGE_SRC to challengeName.value,
-    )
+    ]
 
   private suspend fun Challenge.parseChallengeResults(content: String): List<ChallengeResult> {
     var cnt = 0