[ci] refactor: Cleanup tooling for handling arch build output <= Flutter v3.13.x

packages/pigeon/tool/shared/test_suites.dart

@@ -4,6 +4,7 @@
 
 // ignore_for_file: avoid_print
 
+import 'dart:ffi';
 import 'dart:io' show Directory, File;
 
 import 'package:meta/meta.dart';
@@ -411,17 +412,31 @@ Future<int> _runLinuxUnitTests({bool ciMode = false}) async {
 
   const buildDirBase = '$examplePath/build/linux';
   const buildRelativeBinaryPath = 'debug/plugins/test_plugin/test_plugin_test';
-  const arm64Path = '$buildDirBase/arm64/$buildRelativeBinaryPath';
-  const x64Path = '$buildDirBase/x64/$buildRelativeBinaryPath';
-  final testBinary = File(arm64Path).existsSync() ? arm64Path : x64Path;
+
+  final abi = Abi.current();
+  final String? arch = switch (abi) {
+    Abi.linuxArm64 => 'arm64',
+    Abi.linuxX64 => 'x64',
+    Abi.linuxRiscv64 => 'riscv64',
+    _ => null,
+  };
+
+  if (arch == null) {
+    print(
+      'The host platform and architecture "$abi" is not supported for Linux test suite.',
+    );
+    return 1;
+  }
+
+  final binaryPath = '$buildDirBase/$arch/$buildRelativeBinaryPath';
   if (ciMode) {
     // To avoid having all custom tests in the repo run under xvfb, xvfb-run is
     // done here rather than at the CI config level. Ideally, Pigeon tests
     // should be incorporated into the repo tooling's standard runs, at which
     // point this won't be necessary.
-    return runProcess('xvfb-run', <String>[testBinary]);
+    return runProcess('xvfb-run', <String>[binaryPath]);
   } else {
-    return runProcess(testBinary, <String>[]);
+    return runProcess(binaryPath, <String>[]);
   }
 }
 
@@ -446,25 +461,26 @@ Future<int> _runWindowsUnitTests({bool ciMode = false}) async {
     return compileCode;
   }
 
-  // Depending on the Flutter version, the build output path may be different.
-  // To handle both master and stable, and to future-proof against the changes
-  // that will happen in https://github.com/flutter/flutter/issues/129807
-  // - Try arm64, to future-proof against arm64 support.
-  // - Try x64, to cover pre-arm64 support on arm64 hosts, as well as x64 hosts.
-  // TODO(stuartmorgan): Remove all this when these tests no longer need to
-  // support a version of Flutter without
-  // https://github.com/flutter/flutter/issues/129807, and just construct the
-  // version of the path with the current architecture.
   const buildDirBase = '$examplePath/build/windows';
   const buildRelativeBinaryPath =
       'plugins/test_plugin/Debug/test_plugin_test.exe';
-  const arm64Path = '$buildDirBase/arm64/$buildRelativeBinaryPath';
-  const x64Path = '$buildDirBase/x64/$buildRelativeBinaryPath';
-  if (File(arm64Path).existsSync()) {
-    return runProcess(arm64Path, <String>[]);
-  } else {
-    return runProcess(x64Path, <String>[]);
+
+  final abi = Abi.current();
+  final String? arch = switch (abi) {
+    Abi.windowsArm64 => 'arm64',
+    Abi.windowsX64 => 'x64',
+    _ => null,
+  };
+
+  if (arch == null) {
+    print(
+      'The host platform and architecture "$abi" is not supported for Windows test suite.',
+    );
+    return 1;
   }
+
+  final binaryPath = '$buildDirBase/$arch/$buildRelativeBinaryPath';
+  return runProcess(binaryPath, <String>[]);
 }
 
 Future<int> _runWindowsIntegrationTests({bool ciMode = false}) async {

script/tool/lib/src/common/cmake.dart

@@ -20,7 +20,7 @@ class CMakeProject {
     required this.buildMode,
     this.processRunner = const ProcessRunner(),
     this.platform = const LocalPlatform(),
-    this.arch,
+    required this.arch,
   });
 
   /// The directory of a Flutter project to run Gradle commands in.
@@ -33,13 +33,11 @@ class CMakeProject {
   final Platform platform;
 
   /// The architecture subdirectory of the build.
-  // TODO(stuartmorgan): Make this non-nullable once Flutter 3.13 is no longer
-  // supported, since at that point there will always be a subdirectory.
-  final String? arch;
+  final String arch;
 
   /// The build mode (e.g., Debug, Release).
   ///
-  /// This is a constructor paramater because on Linux many properties depend
+  /// This is a constructor parameter because on Linux many properties depend
   /// on the build mode since it uses a single-configuration generator.
   final String buildMode;
 
@@ -52,10 +50,8 @@ class CMakeProject {
   Directory get buildDirectory {
     Directory buildDir = flutterProject
         .childDirectory('build')
-        .childDirectory(_platformDirName);
-    if (arch != null) {
-      buildDir = buildDir.childDirectory(arch!);
-    }
+        .childDirectory(_platformDirName)
+        .childDirectory(arch);
     if (platform.isLinux) {
       // Linux uses a single-config generator, so the base build directory
       // includes the configuration.

script/tool/lib/src/native_test_command.dart

@@ -677,51 +677,29 @@ this command.
     final testBinaries = <File>[];
     var hasMissingBuild = false;
     var buildFailed = false;
-    String? arch;
-    const x64DirName = 'x64';
-    const arm64DirName = 'arm64';
-    if (platform.isWindows) {
-      arch = _abi == Abi.windowsX64 ? x64DirName : arm64DirName;
-    } else if (platform.isLinux) {
-      // TODO(stuartmorgan): Support arm64 if that ever becomes a supported
-      // CI configuration for the repository.
-      arch = 'x64';
+
+    final String? arch = switch (_abi) {
+      Abi.windowsX64 || Abi.linuxX64 => 'x64',
+      Abi.windowsArm64 || Abi.linuxArm64 => 'arm64',
+      _ => null,
+    };
+
+    if (arch == null) {
+      return _PlatformResult(
+        RunState.failed,
+        error:
+            'Testing on platform and architecture "$_abi" as CMakeProjects is not supported.',
+      );
     }
+
     for (final RepositoryPackage example in plugin.getExamples()) {
-      var project = CMakeProject(
+      final project = CMakeProject(
         example.directory,
         buildMode: buildMode,
         processRunner: processRunner,
         platform: platform,
         arch: arch,
       );
-      if (platform.isWindows) {
-        if (arch == arm64DirName && !project.isConfigured()) {
-          // Check for x64, to handle builds newer than 3.13, but that don't yet
-          // have https://github.com/flutter/flutter/issues/129807.
-          // TODO(stuartmorgan): Remove this when CI no longer supports a
-          // version of Flutter without the issue above fixed.
-          project = CMakeProject(
-            example.directory,
-            buildMode: buildMode,
-            processRunner: processRunner,
-            platform: platform,
-            arch: x64DirName,
-          );
-        }
-        if (!project.isConfigured()) {
-          // Check again without the arch subdirectory, since 3.13 doesn't
-          // have it yet.
-          // TODO(stuartmorgan): Remove this when CI no longer supports Flutter
-          // 3.13.
-          project = CMakeProject(
-            example.directory,
-            buildMode: buildMode,
-            processRunner: processRunner,
-            platform: platform,
-          );
-        }
-      }
       if (!project.isConfigured()) {
         printError(
           'ERROR: Run "flutter build" on ${example.displayName}, '