fix: replace ReadAllLines with ReadAllText in MigrationChecks.targets…

src/ElectronNET.IntegrationTests/Tests/MigrationChecksTargetsTests.cs

@@ -0,0 +1,111 @@
+using System.Diagnostics;
+
+namespace ElectronNET.IntegrationTests.Tests;
+
+/// <summary>
+/// Unit tests for ElectronNET.MigrationChecks.targets — no Electron runtime required.
+/// Covers GitHub issue #1035: System.IO.File.ReadAllLines is not available as an MSBuild
+/// property function on all platforms (e.g. macOS GitHub Actions), causing MSB4185.
+/// </summary>
+public class MigrationChecksTargetsTests
+{
+    // AppContext.BaseDirectory resolves to:
+    //   src\ElectronNET.IntegrationTests\bin\Debug\net10.0\win-x64\
+    // Five levels up => src\
+    private static readonly string TargetsFilePath = Path.GetFullPath(
+        Path.Combine(
+            AppContext.BaseDirectory,
+            "..", "..", "..", "..", "..",
+            "ElectronNET", "build", "ElectronNET.MigrationChecks.targets"));
+
+    // -----------------------------------------------------------------------
+    // Content-level test (RED before fix, GREEN after fix on ALL platforms)
+    // -----------------------------------------------------------------------
+
+    [Fact]
+    public void MigrationChecksTargets_ShouldNotUseReadAllLines()
+    {
+        // The file must exist — if this fails the path constant above is wrong.
+        File.Exists(TargetsFilePath).Should().BeTrue(
+            $"targets file must exist at '{TargetsFilePath}'");
+
+        var content = File.ReadAllText(TargetsFilePath);
+
+        // System.IO.File::ReadAllLines is not in the MSBuild property-function
+        // whitelist on all platforms (MSB4185 on macOS GitHub Actions, see #1035).
+        // ReadAllText must be used instead.
+        content.Should().NotContain(
+            "::ReadAllLines(",
+            "because ReadAllLines is not available as an MSBuild property function on all " +
+            "platforms. Use ReadAllText instead (GitHub issue #1035).");
+    }
+
+    // -----------------------------------------------------------------------
+    // Functional build test — verifies no MSB4185 at runtime
+    // (RED on platforms where ReadAllLines is restricted, GREEN after fix)
+    // -----------------------------------------------------------------------
+
+    [Fact]
+    public async Task MigrationChecksTargets_BuildWithPackageJsonContainingElectron_ShouldSucceedWithoutMSB4185()
+    {
+        var tempDir = Path.Combine(Path.GetTempPath(), $"electron-net-test-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(tempDir);
+        try
+        {
+            // Create a minimal package.json that contains "electron" so ELECTRON008 fires.
+            await File.WriteAllTextAsync(
+                Path.Combine(tempDir, "package.json"),
+                """{ "devDependencies": { "electron": "^30.0.0" } }""");
+
+            // Create a minimal csproj that only imports the migration checks targets.
+            // We deliberately import just that one targets file to keep the build fast.
+            var targetsPathEscaped = TargetsFilePath.Replace("'", "&apos;");
+            await File.WriteAllTextAsync(
+                Path.Combine(tempDir, "TestApp.csproj"),
+                $"""
+                <Project>
+                  <PropertyGroup>
+                    <MSBuildProjectDirectory>{tempDir}</MSBuildProjectDirectory>
+                  </PropertyGroup>
+                  <Import Project="{targetsPathEscaped}" />
+                  <Target Name="Build" DependsOnTargets="ElectronMigrationChecks" />
+                </Project>
+                """);
+
+            // ACT — run the Build target
+            var (exitCode, output) = await RunDotnetBuildAsync(tempDir);
+
+            // ASSERT — the build must not produce the MSB4185 "unavailable function" error
+            output.Should().NotContain(
+                "MSB4185",
+                $"ReadAllLines must not be used as an MSBuild property function. " +
+                $"Full build output:\n{output}");
+        }
+        finally
+        {
+            Directory.Delete(tempDir, recursive: true);
+        }
+    }
+
+    // -----------------------------------------------------------------------
+    // Helper
+    // -----------------------------------------------------------------------
+
+    private static async Task<(int ExitCode, string Output)> RunDotnetBuildAsync(string workingDirectory)
+    {
+        var psi = new ProcessStartInfo("dotnet", "build --nologo -v:minimal")
+        {
+            WorkingDirectory = workingDirectory,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+        };
+
+        using var process = Process.Start(psi)!;
+        var stdOut = await process.StandardOutput.ReadToEndAsync();
+        var stdErr = await process.StandardError.ReadToEndAsync();
+        await process.WaitForExitAsync();
+
+        return (process.ExitCode, stdOut + stdErr);
+    }
+}

src/ElectronNET/build/ElectronNET.MigrationChecks.targets

@@ -73,12 +73,11 @@ EXCEPTION:
   <Target Name="ElectronCheckRootPackageJsonNoElectron"
           Condition="Exists('$(MSBuildProjectDirectory)\package.json')">
 
-    <ItemGroup>
-      <_RootPackageJsonLines Include="$([System.IO.File]::ReadAllLines('$(MSBuildProjectDirectory)\package.json'))" />
-    </ItemGroup>
-
     <PropertyGroup>
-      <_RootPackageJsonContent>@(_RootPackageJsonLines, ' ')</_RootPackageJsonContent>
+      <!-- ReadAllText is used here instead of ReadAllLines because ReadAllLines is not available
+           as an MSBuild property function on all platforms (e.g. macOS GitHub Actions), which
+           caused MSB4185. ReadAllText is universally supported. See GitHub issue #1035. -->
+      <_RootPackageJsonContent>$([System.IO.File]::ReadAllText('$(MSBuildProjectDirectory)\package.json'))</_RootPackageJsonContent>
       <_RootPackageJsonHasElectron>false</_RootPackageJsonHasElectron>
       <_RootPackageJsonHasElectron Condition="$([System.Text.RegularExpressions.Regex]::IsMatch('$(_RootPackageJsonContent)', 'electron', System.Text.RegularExpressions.RegexOptions.IgnoreCase))">true</_RootPackageJsonHasElectron>
     </PropertyGroup>