Add spaces after flow control statements (#126320)

dev/bots/analyze.dart

@@ -112,6 +112,9 @@ Future<void> run(List<String> arguments) async {
   printProgress('Trailing spaces...');
   await verifyNoTrailingSpaces(flutterRoot); // assumes no unexpected binaries, so should be after verifyNoBinaries
 
+  printProgress('Spaces after flow control statements...');
+  await verifySpacesAfterFlowControlStatements(flutterRoot);
+
   printProgress('Deprecations...');
   await verifyDeprecations(flutterRoot);
 
@@ -1040,6 +1043,38 @@ Future<void> verifyNoTrailingSpaces(String workingDirectory, { int minimumMatche
   }
 }
 
+final RegExp _flowControlStatementWithoutSpace = RegExp(r'(^|[ \t])(if|switch|for|do|while|catch)\(', multiLine: true);
+
+Future<void> verifySpacesAfterFlowControlStatements(String workingDirectory, { int minimumMatches = 4000 }) async {
+  const Set<String> extensions = <String>{
+    '.dart',
+    '.java',
+    '.js',
+    '.kt',
+    '.swift',
+    '.c',
+    '.cc',
+    '.cpp',
+    '.h',
+    '.m',
+  };
+  final List<File> files = await _allFiles(workingDirectory, null, minimumMatches: minimumMatches)
+    .where((File file) => extensions.contains(path.extension(file.path)))
+    .toList();
+  final List<String> problems = <String>[];
+  for (final File file in files) {
+    final List<String> lines = file.readAsLinesSync();
+    for (int index = 0; index < lines.length; index += 1) {
+      if (lines[index].contains(_flowControlStatementWithoutSpace)) {
+        problems.add('${file.path}:${index + 1}: no space after flow control statement');
+      }
+    }
+  }
+  if (problems.isNotEmpty) {
+    foundError(problems);
+  }
+}
+
 String _bullets(String value) => ' * $value';
 
 Future<void> verifyIssueLinks(String workingDirectory) async {

dev/bots/test/analyze-test-input/root/packages/foo/spaces_after_flow.dart

@@ -0,0 +1,37 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// ignore_for_file: type=lint
+
+bool isThereMeaningOfLife = true;
+
+void main() {
+  if (isThereMeaningOfLife) {}
+  if(isThereMeaningOfLife) {}
+  //^
+
+  switch (isThereMeaningOfLife) {
+    case false:
+    case true:
+  }
+  switch(isThereMeaningOfLife) {
+  //    ^
+    case false:
+    case true:
+  }
+
+  for (int index = 0; index < 10; index++) {}
+  for(int index = 0; index < 10; index++) {}
+  // ^
+
+  while (isThereMeaningOfLife) {}
+  while(isThereMeaningOfLife) {}
+  //   ^
+
+  try {
+  } catch (e) {}
+  try {
+  } catch(e) {}
+  //     ^
+}

dev/bots/test/analyze_test.dart

@@ -124,6 +124,24 @@ void main() {
     );
   });
 
+  test('analyze.dart - verifySpacesAfterFlowControlStatements', () async {
+    final String result = await capture(() => verifySpacesAfterFlowControlStatements(testRootPath, minimumMatches: 2), shouldHaveErrors: true);
+    final String lines = <String>[
+        '║ test/analyze-test-input/root/packages/foo/spaces_after_flow.dart:11: no space after flow control statement',
+        '║ test/analyze-test-input/root/packages/foo/spaces_after_flow.dart:18: no space after flow control statement',
+        '║ test/analyze-test-input/root/packages/foo/spaces_after_flow.dart:25: no space after flow control statement',
+        '║ test/analyze-test-input/root/packages/foo/spaces_after_flow.dart:29: no space after flow control statement',
+        '║ test/analyze-test-input/root/packages/foo/spaces_after_flow.dart:35: no space after flow control statement',
+      ]
+      .map((String line) => line.replaceAll('/', Platform.isWindows ? r'\' : '/'))
+      .join('\n');
+    expect(result,
+      '╔═╡ERROR╞═══════════════════════════════════════════════════════════════════════\n'
+      '$lines\n'
+      '╚═══════════════════════════════════════════════════════════════════════════════\n'
+    );
+  });
+
   test('analyze.dart - verifyNoBinaries - positive', () async {
     final String result = await capture(() => verifyNoBinaries(
       testRootPath,