Emit hygienic generated code and add diagnostics for the content of the .resw files

README.md

@@ -66,6 +66,23 @@ ReswPlus allows multiple variants of a string based on different criteria, such
 
 🗨 [How to Use Variants](https://github.com/reswplus/ReswPlus/wiki/Features:-Variants)
 
+### Resource Diagnostics
+ReswPlus checks the content of your `.resw` files while it generates the code, and reports the inconsistencies that would otherwise only show up at runtime, in a language your team may not read.
+
+| Rule | Description |
+| --- | --- |
+| `RESWP0006` | A translated value drops placeholders its value in the default language uses, silently losing information. |
+| `RESWP0007` | A value uses a placeholder that has no matching parameter in its `#Format` tag. |
+| `RESWP0008` | A pluralized resource is missing the plural forms its language requires, which silently produces grammatically wrong text. |
+| `RESWP0009` | Two resources of the same file conflict with each other, because their names only differ by case or because a plain resource collides with a pluralized one. |
+| `RESWP0010` | A value that is used as a composite format string is malformed. |
+
+These are reported as **warnings**, so that updating the package never breaks a build that already has an inconsistency. Escalate the ones you want to be fatal from your `.editorconfig`:
+
+```ini
+dotnet_diagnostic.RESWP0006.severity = error
+```
+
 ## Tools
 In addition to features to enrich resw files, ReswPlus also provides some interesting tools to improve your productivity or make it easier to use/support resw files in your workflow and localization process.
 

samples/UWP/ReswPlusUWPSample/ReswPlusUWPSample.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <Import Project="..\..\..\nuget\ReswPlus.targets" />
@@ -12,7 +12,7 @@
     <AssemblyName>ReswPlusUWPSample</AssemblyName>
     <DefaultLanguage>en-US</DefaultLanguage>
     <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion Condition=" '$(TargetPlatformVersion)' == '' ">10.0.22000.0</TargetPlatformVersion>
+    <TargetPlatformVersion Condition=" '$(TargetPlatformVersion)' == '' ">10.0.26100.0</TargetPlatformVersion>
     <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
     <MinimumVisualStudioVersion>14</MinimumVisualStudioVersion>
     <FileAlignment>512</FileAlignment>
@@ -21,7 +21,8 @@
     <PackageCertificateThumbprint>
     </PackageCertificateThumbprint>
     <PackageCertificateKeyFile>ReswPlusUWPSample_TemporaryKey.pfx</PackageCertificateKeyFile>
-    <AppxPackageSigningEnabled>True</AppxPackageSigningEnabled>
+    <!-- The temporary certificate of this sample expired, and signing a package is not needed to build it -->
+    <AppxPackageSigningEnabled>False</AppxPackageSigningEnabled>
     <Use64BitCompiler>true</Use64BitCompiler>
     <GenerateAppInstallerFile>False</GenerateAppInstallerFile>
     <AppxPackageSigningTimestampDigestAlgorithm>SHA256</AppxPackageSigningTimestampDigestAlgorithm>

samples/UWP/ReswPlusUWPSample/Strings/fr/Resources.resw

@@ -121,11 +121,11 @@
     <value>Contoso for Android</value>
   </data>
   <data name="AnimalTreat_Variant1_One" xml:space="preserve">
-    <value>Récompensez votre chiot, donnez {0} biscuit à {1} !</value>
+    <value>Récompensez votre chiot, donnez {0} biscuit à {2} !</value>
     <comment>#Format[Plural Double treatNumber, Variant petType, String petName]</comment>
   </data>
   <data name="AnimalTreat_Variant1_Other" xml:space="preserve">
-    <value>Récompensez votre chiot, donnez {0} biscuits à {1} !</value>
+    <value>Récompensez votre chiot, donnez {0} biscuits à {2} !</value>
   </data>
   <data name="AnimalTreat_Variant2_One" xml:space="preserve">
     <value>Récompensez votre chaton, donnez {0} biscuit à votre chat {2} !</value>

samples/UWP/ReswPlusUWPSampleExternalLibrary/ReswPlusUWPSampleExternalLibrary.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <Import Project="..\..\..\nuget\ReswPlus.targets" />
@@ -12,7 +12,7 @@
     <AssemblyName>ReswPlusUWPSampleExternalLibrary</AssemblyName>
     <DefaultLanguage>en</DefaultLanguage>
     <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion Condition=" '$(TargetPlatformVersion)' == '' ">10.0.22000.0</TargetPlatformVersion>
+    <TargetPlatformVersion Condition=" '$(TargetPlatformVersion)' == '' ">10.0.26100.0</TargetPlatformVersion>
     <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
     <MinimumVisualStudioVersion>14</MinimumVisualStudioVersion>
     <FileAlignment>512</FileAlignment>

samples/WinAppSDK/ReswPlusWinAppSDKSample/Strings/fr/Resources.resw

@@ -121,11 +121,11 @@
     <value>Contoso for Android</value>
   </data>
   <data name="AnimalTreat_Variant1_One" xml:space="preserve">
-    <value>Récompensez votre chiot, donnez {0} biscuit à {1} !</value>
+    <value>Récompensez votre chiot, donnez {0} biscuit à {2} !</value>
     <comment>#Format[Plural Double treatNumber, Variant petType, String petName]</comment>
   </data>
   <data name="AnimalTreat_Variant1_Other" xml:space="preserve">
-    <value>Récompensez votre chiot, donnez {0} biscuits à {1} !</value>
+    <value>Récompensez votre chiot, donnez {0} biscuits à {2} !</value>
   </data>
   <data name="AnimalTreat_Variant2_One" xml:space="preserve">
     <value>Récompensez votre chaton, donnez {0} biscuit à votre chat {2} !</value>

src/ReswPlus.SourceGenerator/Analysis/CompositeFormatString.cs

@@ -0,0 +1,169 @@
+using System.Collections.Generic;
+using System.Globalization;
+
+namespace ReswPlus.SourceGenerator.Analysis;
+
+/// <summary>
+/// Parses the composite format strings used by the values of formatted resources.
+/// </summary>
+/// <remarks>
+/// The generated code passes the value of a formatted resource to <see cref="string.Format(string, object[])"/>,
+/// so a value that this parser rejects is guaranteed to throw a <see cref="System.FormatException"/> at runtime.
+/// The parser is deliberately permissive where the runtime is: it accepts anything the runtime accepts, so that
+/// no valid value is ever reported.
+/// </remarks>
+internal static class CompositeFormatString
+{
+    /// <summary>
+    /// Extracts the set of argument indexes referenced by a composite format string.
+    /// </summary>
+    /// <param name="value">The composite format string to parse.</param>
+    /// <param name="indexes">The distinct argument indexes it references, in ascending order.</param>
+    /// <returns>Whether <paramref name="value"/> is a valid composite format string.</returns>
+    public static bool TryGetArgumentIndexes(string value, out SortedSet<int> indexes)
+    {
+        indexes = new SortedSet<int>();
+
+        var position = 0;
+
+        while (position < value.Length)
+        {
+            var character = value[position];
+
+            if (character == '}')
+            {
+                // Outside of a format item, a closing brace only stands for itself when it is doubled.
+                if (position + 1 < value.Length && value[position + 1] == '}')
+                {
+                    position += 2;
+                    continue;
+                }
+
+                return false;
+            }
+
+            if (character != '{')
+            {
+                position++;
+                continue;
+            }
+
+            // A doubled opening brace stands for a literal brace, it doesn't open a format item.
+            if (position + 1 < value.Length && value[position + 1] == '{')
+            {
+                position += 2;
+                continue;
+            }
+
+            if (!TryReadFormatItem(value, ref position, out var index))
+            {
+                return false;
+            }
+
+            _ = indexes.Add(index);
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    /// Reads a single <c>{index[,alignment][:format]}</c> item, starting from its opening brace.
+    /// </summary>
+    private static bool TryReadFormatItem(string value, ref int position, out int index)
+    {
+        index = 0;
+
+        // Skip the opening brace.
+        position++;
+
+        if (!TryReadInteger(value, ref position, out index))
+        {
+            return false;
+        }
+
+        SkipWhiteSpace(value, ref position);
+
+        if (position < value.Length && value[position] == ',')
+        {
+            position++;
+
+            SkipWhiteSpace(value, ref position);
+
+            if (position < value.Length && (value[position] == '-' || value[position] == '+'))
+            {
+                position++;
+            }
+
+            if (!TryReadInteger(value, ref position, out _))
+            {
+                return false;
+            }
+
+            SkipWhiteSpace(value, ref position);
+        }
+
+        if (position < value.Length && value[position] == ':' && !TrySkipFormatSpecifier(value, ref position))
+        {
+            return false;
+        }
+
+        if (position >= value.Length || value[position] != '}')
+        {
+            return false;
+        }
+
+        position++;
+
+        return true;
+    }
+
+    /// <summary>
+    /// Skips the <c>:format</c> part of a format item, stopping on the closing brace of the item.
+    /// </summary>
+    private static bool TrySkipFormatSpecifier(string value, ref int position)
+    {
+        // Skip the colon.
+        position++;
+
+        while (position < value.Length)
+        {
+            var character = value[position];
+
+            if (character is '{' or '}')
+            {
+                // Braces are escaped by doubling them inside a format specifier as well.
+                if (position + 1 < value.Length && value[position + 1] == character)
+                {
+                    position += 2;
+                    continue;
+                }
+
+                return character == '}';
+            }
+
+            position++;
+        }
+
+        return false;
+    }
+
+    private static bool TryReadInteger(string value, ref int position, out int result)
+    {
+        var start = position;
+
+        while (position < value.Length && char.IsDigit(value[position]))
+        {
+            position++;
+        }
+
+        return int.TryParse(value.Substring(start, position - start), NumberStyles.None, CultureInfo.InvariantCulture, out result);
+    }
+
+    private static void SkipWhiteSpace(string value, ref int position)
+    {
+        while (position < value.Length && value[position] == ' ')
+        {
+            position++;
+        }
+    }
+}