Update the tool to know about all our new platforms (#132423)

...and add a test so we remember to keep it in sync.

dev/bots/analyze.dart

@@ -87,6 +87,9 @@ Future<void> run(List<String> arguments) async {
     foundError(<String>['The analyze.dart script must be run with --enable-asserts.']);
   }
 
+  printProgress('TargetPlatform tool/framework consistency');
+  await verifyTargetPlatform(flutterRoot);
+
   printProgress('No Double.clamp');
   await verifyNoDoubleClamp(flutterRoot);
 
@@ -266,6 +269,84 @@ class _DoubleClampVisitor extends RecursiveAstVisitor<CompilationUnit> {
   }
 }
 
+Future<void> verifyTargetPlatform(String workingDirectory) async {
+  final File framework = File('$workingDirectory/packages/flutter/lib/src/foundation/platform.dart');
+  final Set<String> frameworkPlatforms = <String>{};
+  List<String> lines = framework.readAsLinesSync();
+  int index = 0;
+  while (true) {
+    if (index >= lines.length) {
+      foundError(<String>['${framework.path}: Can no longer find TargetPlatform enum.']);
+      return;
+    }
+    if (lines[index].startsWith('enum TargetPlatform {')) {
+      index += 1;
+      break;
+    }
+    index += 1;
+  }
+  while (true) {
+    if (index >= lines.length) {
+      foundError(<String>['${framework.path}: Could not find end of TargetPlatform enum.']);
+      return;
+    }
+    String line = lines[index].trim();
+    final int comment = line.indexOf('//');
+    if (comment >= 0) {
+      line = line.substring(0, comment);
+    }
+    if (line == '}') {
+      break;
+    }
+    if (line.isNotEmpty) {
+      if (line.endsWith(',')) {
+        frameworkPlatforms.add(line.substring(0, line.length - 1));
+      } else {
+        foundError(<String>['${framework.path}:$index: unparseable line when looking for TargetPlatform values']);
+      }
+    }
+    index += 1;
+  }
+  final File tool = File('$workingDirectory/packages/flutter_tools/lib/src/resident_runner.dart');
+  final Set<String> toolPlatforms = <String>{};
+  lines = tool.readAsLinesSync();
+  index = 0;
+  while (true) {
+    if (index >= lines.length) {
+      foundError(<String>['${tool.path}: Can no longer find nextPlatform logic.']);
+      return;
+    }
+    if (lines[index].trim().startsWith('const List<String> platforms = <String>[')) {
+      index += 1;
+      break;
+    }
+    index += 1;
+  }
+  while (true) {
+    if (index >= lines.length) {
+      foundError(<String>['${tool.path}: Could not find end of nextPlatform logic.']);
+      return;
+    }
+    final String line = lines[index].trim();
+    if (line.startsWith("'") && line.endsWith("',")) {
+      toolPlatforms.add(line.substring(1, line.length - 2));
+    } else if (line == '];') {
+      break;
+    } else {
+      foundError(<String>['${tool.path}:$index: unparseable line when looking for nextPlatform values']);
+    }
+    index += 1;
+  }
+  final Set<String> frameworkExtra = frameworkPlatforms.difference(toolPlatforms);
+  if (frameworkExtra.isNotEmpty) {
+    foundError(<String>['TargetPlatform has some extra values not found in the tool: ${frameworkExtra.join(", ")}']);
+  }
+  final Set<String> toolExtra = toolPlatforms.difference(frameworkPlatforms);
+  if (toolExtra.isNotEmpty) {
+    foundError(<String>['The nextPlatform logic in the tool has some extra values not found in TargetPlatform: ${toolExtra.join(", ")}']);
+  }
+}
+
 /// Verify that we use clampDouble instead of Double.clamp for performance reasons.
 ///
 /// We currently can't distinguish valid uses of clamp from problematic ones so

packages/flutter/lib/src/foundation/binding.dart

@@ -561,33 +561,22 @@ abstract class BindingBase {
         name: FoundationServiceExtensions.platformOverride.name,
         callback: (Map<String, String> parameters) async {
           if (parameters.containsKey('value')) {
-            switch (parameters['value']) {
-              case 'android':
-                debugDefaultTargetPlatformOverride = TargetPlatform.android;
-              case 'fuchsia':
-                debugDefaultTargetPlatformOverride = TargetPlatform.fuchsia;
-              case 'iOS':
-                debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
-              case 'linux':
-                debugDefaultTargetPlatformOverride = TargetPlatform.linux;
-              case 'macOS':
-                debugDefaultTargetPlatformOverride = TargetPlatform.macOS;
-              case 'windows':
-                debugDefaultTargetPlatformOverride = TargetPlatform.windows;
-              case 'default':
-              default:
-                debugDefaultTargetPlatformOverride = null;
+            final String value = parameters['value']!;
+            debugDefaultTargetPlatformOverride = null;
+            for (final TargetPlatform candidate in TargetPlatform.values) {
+              if (candidate.name == value) {
+                debugDefaultTargetPlatformOverride = candidate;
+                break;
+              }
             }
             _postExtensionStateChangedEvent(
               FoundationServiceExtensions.platformOverride.name,
-              defaultTargetPlatform.toString().substring('$TargetPlatform.'.length),
+              defaultTargetPlatform.name,
             );
             await reassembleApplication();
           }
           return <String, dynamic>{
-            'value': defaultTargetPlatform
-                     .toString()
-                     .substring('$TargetPlatform.'.length),
+            'value': defaultTargetPlatform.name,
           };
         },
       );

packages/flutter/lib/src/foundation/platform.dart

@@ -35,7 +35,7 @@ import '_platform_io.dart'
 //
 // When adding support for a new platform (e.g. Windows Phone, Raspberry Pi),
 // first create a new value on the [TargetPlatform] enum, then add a rule for
-// selecting that platform here.
+// selecting that platform in `_platform_io.dart` and `_platform_web.dart`.
 //
 // It would be incorrect to make a platform that isn't supported by
 // [TargetPlatform] default to the behavior of another platform, because doing
@@ -47,6 +47,15 @@ TargetPlatform get defaultTargetPlatform => platform.defaultTargetPlatform;
 /// The platform that user interaction should adapt to target.
 ///
 /// The [defaultTargetPlatform] getter returns the current platform.
+///
+/// When using the "flutter run" command, the "o" key will toggle between
+/// values of this enum when updating [debugDefaultTargetPlatformOverride].
+/// This lets one test how the application will work on various platforms
+/// without having to switch emulators or physical devices.
+//
+// When you add values here, make sure to also add them to
+// nextPlatform() in flutter_tools/lib/src/resident_runner.dart so that
+// the tool can support the new platform for its "o" option.
 enum TargetPlatform {
   /// Android: <https://www.android.com/>
   android,

packages/flutter_tools/lib/src/resident_runner.dart

@@ -1877,19 +1877,17 @@ class DebugConnectionInfo {
 /// These values must match what is available in
 /// `packages/flutter/lib/src/foundation/binding.dart`.
 String nextPlatform(String currentPlatform) {
-  switch (currentPlatform) {
-    case 'android':
-      return 'iOS';
-    case 'iOS':
-      return 'fuchsia';
-    case 'fuchsia':
-      return 'macOS';
-    case 'macOS':
-      return 'android';
-    default:
-      assert(false); // Invalid current platform.
-      return 'android';
-  }
+  const List<String> platforms = <String>[
+    'android',
+    'iOS',
+    'windows',
+    'macOS',
+    'linux',
+    'fuchsia',
+  ];
+  final int index = platforms.indexOf(currentPlatform);
+  assert(index >= 0, 'unknown platform "$currentPlatform"');
+  return platforms[(index + 1) % platforms.length];
 }
 
 /// A launcher for the devtools debugger and analysis tool.

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -2210,9 +2210,11 @@ flutter:
 
   testUsingContext('nextPlatform moves through expected platforms', () {
     expect(nextPlatform('android'), 'iOS');
-    expect(nextPlatform('iOS'), 'fuchsia');
-    expect(nextPlatform('fuchsia'), 'macOS');
-    expect(nextPlatform('macOS'), 'android');
+    expect(nextPlatform('iOS'), 'windows');
+    expect(nextPlatform('windows'), 'macOS');
+    expect(nextPlatform('macOS'), 'linux');
+    expect(nextPlatform('linux'), 'fuchsia');
+    expect(nextPlatform('fuchsia'), 'android');
     expect(() => nextPlatform('unknown'), throwsAssertionError);
   });
 

packages/flutter_tools/test/general.shard/terminal_handler_test.dart

@@ -464,10 +464,10 @@ void main() {
           method: 'ext.flutter.platformOverride',
           args: <String, Object>{
             'isolateId': '1',
-            'value': 'fuchsia',
+            'value': 'windows',
           },
           jsonResponse: <String, Object>{
-            'value': 'fuchsia',
+            'value': 'windows',
           },
         ),
         // Request 2.
@@ -496,7 +496,7 @@ void main() {
       await terminalHandler.processTerminalInput('o');
       await terminalHandler.processTerminalInput('O');
 
-      expect(terminalHandler.logger.statusText, contains('Switched operating system to fuchsia'));
+      expect(terminalHandler.logger.statusText, contains('Switched operating system to windows'));
       expect(terminalHandler.logger.statusText, contains('Switched operating system to iOS'));
     });
 
@@ -518,10 +518,10 @@ void main() {
           method: 'ext.flutter.platformOverride',
           args: <String, Object>{
             'isolateId': '1',
-            'value': 'fuchsia',
+            'value': 'windows',
           },
           jsonResponse: <String, Object>{
-            'value': 'fuchsia',
+            'value': 'windows',
           },
         ),
         // Request 2.
@@ -550,7 +550,7 @@ void main() {
       await terminalHandler.processTerminalInput('o');
       await terminalHandler.processTerminalInput('O');
 
-      expect(terminalHandler.logger.statusText, contains('Switched operating system to fuchsia'));
+      expect(terminalHandler.logger.statusText, contains('Switched operating system to windows'));
       expect(terminalHandler.logger.statusText, contains('Switched operating system to iOS'));
     });