[flutter_tools] use ProcessManager.canRun instead of checking for ArgumentErrors (#83845)

packages/flutter_tools/lib/src/base/os.dart

@@ -222,13 +222,7 @@ class _PosixUtils extends OperatingSystemUtils {
   // unzip -o -q zipfile -d dest
   @override
   void unzip(File file, Directory targetDirectory) {
-    try {
-      _processUtils.runSync(
-        <String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
-        throwOnError: true,
-        verboseExceptions: true,
-      );
-    } on ArgumentError {
+    if (!_processManager.canRun('unzip')) {
       // unzip is not available. this error message is modeled after the download
       // error in bin/internal/update_dart_sdk.sh
       String message = 'Please install unzip.';
@@ -241,6 +235,11 @@ class _PosixUtils extends OperatingSystemUtils {
         'Missing "unzip" tool. Unable to extract ${file.path}.\n$message'
       );
     }
+    _processUtils.runSync(
+      <String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
+      throwOnError: true,
+      verboseExceptions: true,
+    );
   }
 
   // tar -xzf tarball -C dest
@@ -454,11 +453,7 @@ class _WindowsUtils extends OperatingSystemUtils {
 
   @override
   List<File> _which(String execName, { bool all = false }) {
-    // `where` always returns all matches, not just the first one.
-    ProcessResult result;
-    try {
-      result = _processManager.runSync(<String>['where', execName]);
-    } on ArgumentError {
+    if (!_processManager.canRun('where')) {
       // `where` could be missing if system32 is not on the PATH.
       throwToolExit(
         'Cannot find the executable for `where`. This can happen if the System32 '
@@ -467,6 +462,8 @@ class _WindowsUtils extends OperatingSystemUtils {
         'the terminal and/or IDE.'
       );
     }
+    // `where` always returns all matches, not just the first one.
+    final ProcessResult result = _processManager.runSync(<String>['where', execName]);
     if (result.exitCode != 0) {
       return const <File>[];
     }

packages/flutter_tools/test/general.shard/base/os_test.dart

@@ -81,16 +81,8 @@ void main() {
   });
 
   group('which on Windows', () {
-    testWithoutContext('throws tool exit if where throws an argument error', () async {
-      fakeProcessManager.addCommand(
-        FakeCommand(
-          command: const <String>[
-            'where',
-            kExecutable,
-          ],
-          exception: ArgumentError('Cannot find executable for where'),
-        ),
-      );
+    testWithoutContext('throws tool exit if where.exe cannot be run', () async {
+      fakeProcessManager.excludedExecutables.add('where');
 
       final OperatingSystemUtils utils = OperatingSystemUtils(
         fileSystem: MemoryFileSystem.test(),
@@ -544,17 +536,10 @@ void main() {
     );
   });
 
-  group('display an install message when unzip throws an ArgumentError', () {
+  group('display an install message when unzip cannot be run', () {
     testWithoutContext('Linux', () {
       final FileSystem fileSystem = MemoryFileSystem.test();
-      fakeProcessManager.addCommand(
-        FakeCommand(
-          command: <String>[
-            'unzip', '-o', '-q', 'foo.zip', '-d', fileSystem.currentDirectory.path,
-          ],
-          exception: ArgumentError(),
-        ),
-      );
+      fakeProcessManager.excludedExecutables.add('unzip');
 
       final OperatingSystemUtils linuxOsUtils = OperatingSystemUtils(
         fileSystem: fileSystem,
@@ -573,14 +558,7 @@ void main() {
 
     testWithoutContext('macOS', () {
       final FileSystem fileSystem = MemoryFileSystem.test();
-      fakeProcessManager.addCommand(
-        FakeCommand(
-          command: <String>[
-            'unzip', '-o', '-q', 'foo.zip', '-d', fileSystem.currentDirectory.path,
-          ],
-          exception: ArgumentError(),
-        ),
-      );
+      fakeProcessManager.excludedExecutables.add('unzip');
 
       final OperatingSystemUtils macOSUtils = OperatingSystemUtils(
         fileSystem: fileSystem,
@@ -590,7 +568,7 @@ void main() {
       );
 
       expect(
-            () => macOSUtils.unzip(fileSystem.file('foo.zip'), fileSystem.currentDirectory),
+        () => macOSUtils.unzip(fileSystem.file('foo.zip'), fileSystem.currentDirectory),
         throwsToolExit
           (message: 'Missing "unzip" tool. Unable to extract foo.zip.\n'
             'Consider running "brew install unzip".'),
@@ -599,14 +577,7 @@ void main() {
 
     testWithoutContext('unknown OS', () {
       final FileSystem fileSystem = MemoryFileSystem.test();
-      fakeProcessManager.addCommand(
-        FakeCommand(
-          command: <String>[
-            'unzip', '-o', '-q', 'foo.zip', '-d', fileSystem.currentDirectory.path,
-          ],
-          exception: ArgumentError(),
-        ),
-      );
+      fakeProcessManager.excludedExecutables.add('unzip');
 
       final OperatingSystemUtils unknownOsUtils = OperatingSystemUtils(
         fileSystem: fileSystem,