Merge subcircuit codegen into the main Circuit processor

CHANGELOG.md

@@ -14,6 +14,12 @@ Unreleased
   - See the [circuit-retained README](https://github.com/slackhq/circuit/tree/main/circuit-retained) for more details.
   - **NOTE:** This is phase one of a multi-phase migration to the first-party API.
 
+### Changed
+
+- **SubCircuit:** `@SubCircuitInject` is now handled by the main `circuit-codegen` processor.
+  `circuitx-subcircuit-codegen` is now a relocation pointer to `circuit-codegen`, but prefer
+  depending on `circuit-codegen` directly.
+
 ### Fixed
 
 - **SubCircuit:** Fix `subcircuit-codegen` Metro mode (`subcircuit.codegen.mode=metro`). It previously

build-logic/src/main/kotlin/circuit.publish.gradle.kts

@@ -49,7 +49,7 @@ configure<DokkaExtension> {
 
 // Dependency guard configuration
 configure<DependencyGuardPluginExtension> {
-  if (project.name == "circuit-codegen" || project.name == "subcircuit-codegen") {
+  if (project.name == "circuit-codegen") {
     configuration("runtimeClasspath") {
       baselineMap = {
         // Remove the version

circuit-codegen/build.gradle.kts

@@ -23,6 +23,7 @@ dependencies {
   testImplementation(libs.kct)
   testImplementation(libs.kct.ksp)
   testImplementation(libs.kotlin.compilerEmbeddable)
+  testImplementation(libs.kotlin.test)
   testImplementation(libs.ksp)
   testImplementation(libs.ksp.api)
   testImplementation(libs.metro)

circuit-codegen/src/main/kotlin/com/slack/circuit/codegen/CircuitNames.kt

@@ -31,6 +31,21 @@ internal object CircuitNames {
   val SCREEN = ClassName(CIRCUIT_RUNTIME_SCREEN_PACKAGE, "Screen")
   val NAVIGATOR = ClassName(CIRCUIT_RUNTIME_BASE_PACKAGE, "Navigator")
   val CIRCUIT_CONTEXT = ClassName(CIRCUIT_RUNTIME_BASE_PACKAGE, "CircuitContext")
+
+  // SubCircuit target. Referenced by string only so circuit-codegen keeps no compile dependency on
+  // the circuitx-subcircuit runtime; these types are resolved from the consumer's classpath when a
+  // `@SubCircuitInject` is present.
+  const val SUB_CIRCUIT_PACKAGE = "com.slack.circuit.subcircuit"
+  val SUB_CIRCUIT_INJECT_ANNOTATION = ClassName(SUB_CIRCUIT_PACKAGE, "SubCircuitInject")
+  val SUB_PRESENTER = ClassName(SUB_CIRCUIT_PACKAGE, "SubPresenter")
+  val SUB_PRESENTER_FACTORY = ClassName(SUB_CIRCUIT_PACKAGE, "SubPresenterFactory")
+  val SUB_UI = ClassName(SUB_CIRCUIT_PACKAGE, "SubUi")
+  val SUB_UI_FACTORY = ClassName(SUB_CIRCUIT_PACKAGE, "SubUiFactory")
+  val SUB_CIRCUIT_UI_STATE = ClassName(SUB_CIRCUIT_PACKAGE, "SubCircuitUiState")
+  val SUB_SCREEN = ClassName(SUB_CIRCUIT_PACKAGE, "SubScreen")
+  const val SUB_PRESENTER_FACTORY_SUFFIX = "_SubPresenterFactory"
+  const val SUB_UI_FACTORY_SUFFIX = "_SubUiFactory"
+
   val DAGGER_MODULE = ClassName(DAGGER_PACKAGE, "Module")
   val DAGGER_BINDS = ClassName(DAGGER_PACKAGE, "Binds")
   val DAGGER_INSTALL_IN = ClassName(DAGGER_HILT_PACKAGE, "InstallIn")

circuit-codegen/src/main/kotlin/com/slack/circuit/codegen/CircuitOptions.kt

@@ -14,12 +14,17 @@ internal data class CircuitOptions(
     const val LENIENT = "circuit.codegen.lenient"
     const val USE_JAVAX_ONLY = "circuit.codegen.useJavaxOnly"
 
+    // `subcircuit.codegen.*` fallbacks for the SubCircuit target; the keys above take precedence.
+    private const val LEGACY_MODE = "subcircuit.codegen.mode"
+    private const val LEGACY_LENIENT = "subcircuit.codegen.lenient"
+    private const val LEGACY_USE_JAVAX_ONLY = "subcircuit.codegen.useJavaxOnly"
+
     internal val UNKNOWN =
       CircuitOptions(CodegenMode.UNKNOWN, lenient = false, useJavaxOnly = false)
 
     fun load(options: Map<String, String>, logger: KSPLogger): CircuitOptions {
       val mode =
-        options[MODE].let { mode ->
+        (options[MODE] ?: options[LEGACY_MODE]).let { mode ->
           if (mode == null) {
             CodegenMode.ANVIL
           } else {
@@ -36,8 +41,9 @@ internal data class CircuitOptions(
         return UNKNOWN
       }
 
-      val lenient = options[LENIENT]?.toBoolean() ?: false
-      val useJavaxOnly = options[USE_JAVAX_ONLY]?.toBoolean() ?: false
+      val lenient = (options[LENIENT] ?: options[LEGACY_LENIENT])?.toBoolean() ?: false
+      val useJavaxOnly =
+        (options[USE_JAVAX_ONLY] ?: options[LEGACY_USE_JAVAX_ONLY])?.toBoolean() ?: false
       return CircuitOptions(mode = mode, lenient = lenient, useJavaxOnly = useJavaxOnly)
     }
   }