[flutter_tool] Make CommandHelp context free (#48584)

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

@@ -4,34 +4,125 @@
 
 import 'dart:math' as math;
 
-import '../globals.dart' as globals;
+import 'package:meta/meta.dart';
+import 'package:platform/platform.dart';
+
+import 'logger.dart';
 import 'terminal.dart';
 
+// ignore_for_file: non_constant_identifier_names
+
 const String fire = '🔥';
 const int maxLineWidth = 84;
 
-/// Encapsulates the help text construction and printing
+/// Encapsulates the help text construction and printing.
 class CommandHelp {
+  CommandHelp({
+    @required Logger logger,
+    @required AnsiTerminal terminal,
+    @required Platform platform,
+    @required OutputPreferences outputPreferences,
+  }) : _logger = logger,
+       _terminal = terminal,
+       _platform = platform,
+       _outputPreferences = outputPreferences;
+
+  final Logger _logger;
+
+  final AnsiTerminal _terminal;
+
+  final Platform _platform;
+
+  final OutputPreferences _outputPreferences;
+
+  CommandHelpOption _L;
+  CommandHelpOption get L => _L ??= _makeOption('L', 'Dump layer tree to the console.', 'debugDumpLayerTree');
+
+  CommandHelpOption _P;
+  CommandHelpOption get P => _P ??= _makeOption('P', 'Toggle performance overlay.', 'WidgetsApp.showPerformanceOverlay');
+
+  CommandHelpOption _R;
+  CommandHelpOption get R => _R ??= _makeOption('R', 'Hot restart.');
+
+  CommandHelpOption _S;
+  CommandHelpOption get S => _S ??= _makeOption('S', 'Dump accessibility tree in traversal order.', 'debugDumpSemantics');
+
+  CommandHelpOption _U;
+  CommandHelpOption get U => _U ??= _makeOption('U', 'Dump accessibility tree in inverse hit test order.', 'debugDumpSemantics');
+
+  CommandHelpOption _a;
+  CommandHelpOption get a => _a ??= _makeOption('a', 'Toggle timeline events for all widget build methods.', 'debugProfileWidgetBuilds');
+
+  CommandHelpOption _d;
+  CommandHelpOption get d => _d ??= _makeOption('d', 'Detach (terminate "flutter run" but leave application running).');
+
+  CommandHelpOption _h;
+  CommandHelpOption get h => _h ??= _makeOption('h', 'Repeat this help message.');
+
+  CommandHelpOption _i;
+  CommandHelpOption get i => _i ??= _makeOption('i', 'Toggle widget inspector.', 'WidgetsApp.showWidgetInspectorOverride');
+
+  CommandHelpOption _o;
+  CommandHelpOption get o => _o ??= _makeOption('o', 'Simulate different operating systems.', 'defaultTargetPlatform');
+
+  CommandHelpOption _p;
+  CommandHelpOption get p => _p ??= _makeOption('p', 'Toggle the display of construction lines.', 'debugPaintSizeEnabled');
+
+  CommandHelpOption _q;
+  CommandHelpOption get q => _q ??= _makeOption('q', 'Quit (terminate the application on the device).');
+
+  CommandHelpOption _r;
+  CommandHelpOption get r => _r ??= _makeOption('r', 'Hot reload. $fire$fire$fire');
+
+  CommandHelpOption _s;
+  CommandHelpOption get s => _s ??= _makeOption('s', 'Save a screenshot to flutter.png.');
+
+  CommandHelpOption _t;
+  CommandHelpOption get t => _t ??= _makeOption('t', 'Dump rendering tree to the console.', 'debugDumpRenderTree');
+
+  CommandHelpOption _w;
+  CommandHelpOption get w => _w ??= _makeOption('w', 'Dump widget hierarchy to the console.', 'debugDumpApp');
+
+  CommandHelpOption _z;
+  CommandHelpOption get z => _z ??= _makeOption('z', 'Toggle elevation checker.');
+
+  CommandHelpOption _makeOption(String key, String description, [
+    String inParenthesis = '',
+  ]) {
+    return CommandHelpOption(
+      key,
+      description,
+      inParenthesis: inParenthesis,
+      logger: _logger,
+      terminal: _terminal,
+      platform: _platform,
+      outputPreferences: _outputPreferences,
+    );
+  }
+}
+
+/// Encapsulates printing help text for a single option.
+class CommandHelpOption {
+  CommandHelpOption(
+    this.key,
+    this.description, {
+    this.inParenthesis = '',
+    @required Logger logger,
+    @required AnsiTerminal terminal,
+    @required Platform platform,
+    @required OutputPreferences outputPreferences,
+  }) : _logger = logger,
+       _terminal = terminal,
+       _platform = platform,
+       _outputPreferences = outputPreferences;
+
+  final Logger _logger;
+
+  final AnsiTerminal _terminal;
+
+  final Platform _platform;
 
-  const CommandHelp._(this.key, this.description, [this.inParenthesis = '']);
-
-  static const CommandHelp L = CommandHelp._('L', 'Dump layer tree to the console.', 'debugDumpLayerTree');
-  static const CommandHelp P = CommandHelp._('P', 'Toggle performance overlay.', 'WidgetsApp.showPerformanceOverlay');
-  static const CommandHelp R = CommandHelp._('R', 'Hot restart.');
-  static const CommandHelp S = CommandHelp._('S', 'Dump accessibility tree in traversal order.', 'debugDumpSemantics');
-  static const CommandHelp U = CommandHelp._('U', 'Dump accessibility tree in inverse hit test order.', 'debugDumpSemantics');
-  static const CommandHelp a = CommandHelp._('a', 'Toggle timeline events for all widget build methods.', 'debugProfileWidgetBuilds');
-  static const CommandHelp d = CommandHelp._('d', 'Detach (terminate "flutter run" but leave application running).');
-  static const CommandHelp h = CommandHelp._('h', 'Repeat this help message.');
-  static const CommandHelp i = CommandHelp._('i', 'Toggle widget inspector.', 'WidgetsApp.showWidgetInspectorOverride');
-  static const CommandHelp o = CommandHelp._('o', 'Simulate different operating systems.', 'defaultTargetPlatform');
-  static const CommandHelp p = CommandHelp._('p', 'Toggle the display of construction lines.', 'debugPaintSizeEnabled');
-  static const CommandHelp q = CommandHelp._('q', 'Quit (terminate the application on the device).');
-  static const CommandHelp r = CommandHelp._('r', 'Hot reload. $fire$fire$fire');
-  static const CommandHelp s = CommandHelp._('s', 'Save a screenshot to flutter.png.');
-  static const CommandHelp t = CommandHelp._('t', 'Dump rendering tree to the console.', 'debugDumpRenderTree');
-  static const CommandHelp w = CommandHelp._('w', 'Dump widget hierarchy to the console.', 'debugDumpApp');
-  static const CommandHelp z = CommandHelp._('z', 'Toggle elevation checker.');
+  final OutputPreferences _outputPreferences;
 
   /// The key associated with this command
   final String key;
@@ -47,12 +138,12 @@ class CommandHelp {
   @override
   String toString() {
     final StringBuffer message = StringBuffer();
-    message.writeAll(<String>[globals.terminal.bolden(key), description], ' ');
+    message.writeAll(<String>[_terminal.bolden(key), description], ' ');
 
     if (_hasTextInParenthesis) {
       bool wrap = false;
-      final int maxWidth = math.max(outputPreferences.wrapColumn ?? 0,  maxLineWidth);
-      int width = maxWidth - (globals.platform.stdoutSupportsAnsi ? _rawMessageLength + 1 : message.length);
+      final int maxWidth = math.max(_outputPreferences.wrapColumn ?? 0,  maxLineWidth);
+      int width = maxWidth - (_platform.stdoutSupportsAnsi ? _rawMessageLength + 1 : message.length);
       final String parentheticalText = '($inParenthesis)';
       if (width < parentheticalText.length) {
         width = maxWidth;
@@ -65,12 +156,12 @@ class CommandHelp {
       // pad according to the raw text
       message.write(''.padLeft(width - parentheticalText.length));
 
-      message.write(globals.terminal.color(parentheticalText, TerminalColor.grey));
+      message.write(_terminal.color(parentheticalText, TerminalColor.grey));
     }
     return message.toString();
   }
 
   void print() {
-    globals.printStatus(toString());
+    _logger.printStatus(toString());
   }
 }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -15,6 +15,7 @@ import 'base/file_system.dart';
 import 'base/io.dart' as io;
 import 'base/logger.dart';
 import 'base/signals.dart';
+import 'base/terminal.dart' show outputPreferences;
 import 'base/utils.dart';
 import 'build_info.dart';
 import 'codegen.dart';
@@ -607,7 +608,13 @@ abstract class ResidentRunner {
        artifactDirectory = dillOutputPath == null
           ? globals.fs.systemTempDirectory.createTempSync('flutter_tool.')
           : globals.fs.file(dillOutputPath).parent,
-       assetBundle = AssetBundleFactory.instance.createBundle() {
+       assetBundle = AssetBundleFactory.instance.createBundle(),
+       commandHelp = CommandHelp(
+         logger: globals.logger,
+         terminal: globals.terminal,
+         platform: globals.platform,
+         outputPreferences: outputPreferences,
+       ) {
     if (!artifactDirectory.existsSync()) {
       artifactDirectory.createSync(recursive: true);
     }
@@ -640,6 +647,8 @@ abstract class ResidentRunner {
   final String mainPath;
   final AssetBundle assetBundle;
 
+  final CommandHelp commandHelp;
+
   bool _exited = false;
   Completer<int> _finished = Completer<int>();
   bool hotMode;
@@ -1005,29 +1014,29 @@ abstract class ResidentRunner {
 
   void printHelpDetails() {
     if (flutterDevices.any((FlutterDevice d) => d.device.supportsScreenshot)) {
-      CommandHelp.s.print();
+      commandHelp.s.print();
     }
     if (supportsServiceProtocol) {
-      CommandHelp.w.print();
-      CommandHelp.t.print();
+      commandHelp.w.print();
+      commandHelp.t.print();
       if (isRunningDebug) {
-        CommandHelp.L.print();
-        CommandHelp.S.print();
-        CommandHelp.U.print();
-        CommandHelp.i.print();
-        CommandHelp.p.print();
-        CommandHelp.o.print();
-        CommandHelp.z.print();
+        commandHelp.L.print();
+        commandHelp.S.print();
+        commandHelp.U.print();
+        commandHelp.i.print();
+        commandHelp.p.print();
+        commandHelp.o.print();
+        commandHelp.z.print();
       } else {
-        CommandHelp.S.print();
-        CommandHelp.U.print();
+        commandHelp.S.print();
+        commandHelp.U.print();
       }
       // `P` should precede `a`
-      CommandHelp.P.print();
-      CommandHelp.a.print();
+      commandHelp.P.print();
+      commandHelp.a.print();
     }
     if (flutterDevices.any((FlutterDevice d) => d.device.supportsScreenshot)) {
-      CommandHelp.s.print();
+      commandHelp.s.print();
     }
   }
 

packages/flutter_tools/lib/src/run_cold.dart

@@ -6,7 +6,6 @@ import 'dart:async';
 
 import 'package:meta/meta.dart';
 
-import 'base/command_help.dart';
 import 'base/file_system.dart';
 import 'device.dart';
 import 'globals.dart' as globals;
@@ -186,11 +185,11 @@ class ColdRunner extends ResidentRunner {
         printHelpDetails();
       }
     }
-    CommandHelp.h.print();
+    commandHelp.h.print();
     if (_didAttach) {
-      CommandHelp.d.print();
+      commandHelp.d.print();
     }
-    CommandHelp.q.print();
+    commandHelp.q.print();
     for (final FlutterDevice device in flutterDevices) {
       final String dname = device.device.name;
       if (device.vmService != null) {

packages/flutter_tools/lib/src/run_hot.dart

@@ -11,7 +11,6 @@ import 'package:meta/meta.dart';
 import 'package:pool/pool.dart';
 import 'base/async_guard.dart';
 
-import 'base/command_help.dart';
 import 'base/context.dart';
 import 'base/file_system.dart';
 import 'base/logger.dart';
@@ -1046,15 +1045,15 @@ class HotRunner extends ResidentRunner {
   @override
   void printHelp({ @required bool details }) {
     globals.printStatus('Flutter run key commands.');
-    CommandHelp.r.print();
+    commandHelp.r.print();
     if (canHotRestart) {
-      CommandHelp.R.print();
+      commandHelp.R.print();
     }
-    CommandHelp.h.print();
+    commandHelp.h.print();
     if (_didAttach) {
-      CommandHelp.d.print();
+      commandHelp.d.print();
     }
-    CommandHelp.q.print();
+    commandHelp.q.print();
     if (details) {
       printHelpDetails();
     }

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

@@ -364,6 +364,8 @@ void main() {
 
     residentRunner.printHelp(details: true);
 
+    final CommandHelp commandHelp = residentRunner.commandHelp;
+
     // supports service protocol
     expect(residentRunner.supportsServiceProtocol, true);
     // isRunningDebug
@@ -372,23 +374,23 @@ void main() {
     expect(testLogger.statusText, equals(
         <dynamic>[
           'Flutter run key commands.',
-          CommandHelp.r,
-          CommandHelp.R,
-          CommandHelp.h,
-          CommandHelp.q,
-          CommandHelp.s,
-          CommandHelp.w,
-          CommandHelp.t,
-          CommandHelp.L,
-          CommandHelp.S,
-          CommandHelp.U,
-          CommandHelp.i,
-          CommandHelp.p,
-          CommandHelp.o,
-          CommandHelp.z,
-          CommandHelp.P,
-          CommandHelp.a,
-          CommandHelp.s,
+          commandHelp.r,
+          commandHelp.R,
+          commandHelp.h,
+          commandHelp.q,
+          commandHelp.s,
+          commandHelp.w,
+          commandHelp.t,
+          commandHelp.L,
+          commandHelp.S,
+          commandHelp.U,
+          commandHelp.i,
+          commandHelp.p,
+          commandHelp.o,
+          commandHelp.z,
+          commandHelp.P,
+          commandHelp.a,
+          commandHelp.s,
           'An Observatory debugger and profiler on null is available at: null',
           ''
         ].join('\n')