feat: suggest sub commands (#22)

example/lib/src/command_runner.dart

@@ -21,10 +21,13 @@ class ExampleCommandRunner extends CompletionCommandRunner<int> {
   })  : _logger = logger ?? Logger(),
         super(executableName, description) {
     // Add root options and flags
-    argParser.addFlag(
-      'rootFlag',
-      help: 'A flag in the root command',
-    );
+    argParser
+      ..addFlag(
+        'rootFlag',
+        abbr: 'f',
+        help: 'A flag: in the root command',
+      )
+      ..addOption('rootOption');
 
     // Add sub commands
     addCommand(SomeCommand(_logger));

example/lib/src/commands/some_commmand.dart

@@ -23,6 +23,7 @@ class SomeCommand extends Command<int> {
         },
         mandatory: true,
       )
+      ..addSeparator('yay')
       ..addOption(
         'hidden',
         hide: true,

example/test/integrated/completion_integrated_test.dart → example/test/integration/completion_integration_test.dart

@@ -17,27 +17,25 @@ void main() {
         'some_other_command': 'This is help for some_other_command',
         '--help': 'Print this usage information.',
         '--rootFlag': r'A flag\: in the root command',
+        '--rootOption': null,
       };
 
       testCompletion(
         'basic usage',
         forLine: 'example_cli',
         suggests: allRootOptionsAndSubcommands,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'leading whitespaces',
         forLine: '   example_cli',
         suggests: allRootOptionsAndSubcommands,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'trailing whitespaces',
         forLine: 'example_cli   ',
         suggests: allRootOptionsAndSubcommands,
-        skip: notImplemmentedYet,
       );
     });
 
@@ -49,6 +47,7 @@ void main() {
           suggests: {
             '--help': 'Print this usage information.',
             '--rootFlag': r'A flag\: in the root command',
+            '--rootOption': null,
           },
           skip: notImplemmentedYet,
         );
@@ -58,6 +57,7 @@ void main() {
           forLine: 'example_cli --r',
           suggests: {
             '--rootFlag': r'A flag\: in the root command',
+            '--rootOption': null,
           },
           skip: notImplemmentedYet,
         );
@@ -67,6 +67,7 @@ void main() {
           forLine: 'example_cli -h --r',
           suggests: {
             '--rootFlag': r'A flag\: in the root command',
+            '--rootOption': null,
           },
           skip: notImplemmentedYet,
         );
@@ -108,7 +109,6 @@ void main() {
             'some_command': 'This is help for some_command',
             'some_other_command': 'This is help for some_other_command',
           },
-          skip: notImplemmentedYet,
         );
 
         testCompletion(
@@ -118,7 +118,6 @@ void main() {
             'some_command': 'This is help for some_command',
             'some_other_command': 'This is help for some_other_command',
           },
-          skip: notImplemmentedYet,
         );
 
         testCompletion(
@@ -127,7 +126,6 @@ void main() {
           suggests: {
             'some_command': 'This is help for some_command',
           },
-          skip: notImplemmentedYet,
         );
       });
 
@@ -138,7 +136,6 @@ void main() {
           suggests: {
             'melon': 'This is help for some_command',
           },
-          skip: notImplemmentedYet,
         );
 
         testCompletion(
@@ -147,7 +144,6 @@ void main() {
           suggests: {
             r'disguised\:some_commmand': 'This is help for some_command',
           },
-          skip: notImplemmentedYet,
         );
       });
 
@@ -172,55 +168,50 @@ void main() {
       '--continuous': r'A continuous option\: any value is allowed',
       '--multi-d': 'An discrete option that can be passed multiple times ',
       '--multi-c': 'An continuous option that can be passed multiple times',
-      '--flag': '',
+      '--flag': null,
       '--inverseflag': 'A flag that the default value is true',
       '--trueflag': 'A flag that cannot be negated'
     };
 
-    final allAbbreviationssInThisLevel = <String, String>{
+    final allAbbreviationssInThisLevel = <String, String?>{
       '-h': 'Print this usage information.',
       '-d': 'A discrete option with "allowed" values (mandatory)',
       '-m': 'An discrete option that can be passed multiple times ',
       '-n': 'An continuous option that can be passed multiple times',
-      '-f': '',
+      '-f': null,
       '-i': 'A flag that the default value is true',
       '-t': 'A flag that cannot be negated'
     };
 
-    group('empty', () {
+    group('empty ', () {
       testCompletion(
         'basic usage',
         forLine: 'example_cli some_command',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'leading spaces',
         forLine: '   example_cli some_command',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'trailing spaces',
         forLine: 'example_cli some_command     ',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'options in between',
-        forLine: 'example_cli -f some_command',
+        forLine: 'example_cli -f --rootOption yay some_command',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'lots of spaces in between',
         forLine: 'example_cli      some_command',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
     });
 
@@ -229,14 +220,12 @@ void main() {
         'shows same options for alias sub command',
         forLine: 'example_cli melon',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
 
       testCompletion(
         'shows same options for alias sub command 2',
         forLine: 'example_cli disguised:some_commmand',
         suggests: allOptionsInThisLevel,
-        skip: notImplemmentedYet,
       );
     });
 
@@ -470,19 +459,19 @@ void main() {
           'subcommand': 'A sub command of some_other_command',
           '--help': 'Print this usage information.',
         },
-        skip: notImplemmentedYet,
       );
     });
+
     group('partially written sub command', () {
       testCompletion(
         'partially written sub command',
         forLine: 'example_cli some_other_command sub',
         suggests: {
           'subcommand': 'A sub command of some_other_command',
         },
-        skip: notImplemmentedYet,
       );
     });
+
     group('subcommand', () {
       final allOptionsInThisLevel = <String, String?>{
         '--help': 'Print this usage information.',
@@ -516,7 +505,6 @@ void main() {
           'basic usage with args in between',
           forLine: 'example_cli some_other_command subcommand_alias',
           suggests: allOptionsInThisLevel,
-          skip: notImplemmentedYet,
         );
       });
     });

example/test/src/command_runner_test.dart

@@ -81,7 +81,8 @@ Usage: example_cli <command> [arguments]
 
 Global options:
 -h, --help             Print this usage information.
-    --[no-]rootFlag    A flag in the root command
+-f, --[no-]rootFlag    A flag: in the root command
+    --rootOption       
 
 Available commands:
   some_command         This is help for some_command

lib/src/command_runner/commands/handle_completion_command.dart

@@ -2,20 +2,21 @@ import 'dart:async';
 
 import 'package:args/command_runner.dart';
 import 'package:cli_completion/src/command_runner/completion_command_runner.dart';
+import 'package:cli_completion/src/handling/completion_level.dart';
 import 'package:cli_completion/src/handling/completion_state.dart';
 import 'package:cli_completion/src/handling/parser.dart';
-import 'package:mason_logger/mason_logger.dart';
 
 /// {@template handle_completion_request_command}
 /// A hidden [Command] added by [CompletionCommandRunner] that handles the
 /// "completion" sub command.
+/// {@endtemplate}
+///
 /// This is called by a shell function when the user presses "tab".
 /// Any output to stdout during this call will be interpreted as suggestions
 /// for completions.
-/// {@endtemplate}
 class HandleCompletionRequestCommand<T> extends Command<T> {
   /// {@macro handle_completion_request_command}
-  HandleCompletionRequestCommand(this.logger);
+  HandleCompletionRequestCommand();
 
   @override
   String get description {
@@ -31,9 +32,6 @@ class HandleCompletionRequestCommand<T> extends Command<T> {
   @override
   bool get hidden => true;
 
-  /// The [Logger] used to display the completion suggestions
-  final Logger logger;
-
   @override
   CompletionCommandRunner<T> get runner {
     return super.runner! as CompletionCommandRunner<T>;
@@ -42,16 +40,38 @@ class HandleCompletionRequestCommand<T> extends Command<T> {
   @override
   FutureOr<T>? run() {
     try {
+      // Get completion request params from the environment
       final completionState = CompletionState.fromEnvironment(
         runner.environmentOverride,
       );
+
+      // If the parameters in the environment are not supported or invalid,
+      // do not proceed with completion complete.
       if (completionState == null) {
         return null;
       }
 
-      final result = CompletionParser(completionState).parse();
+      // Find the completion level
+      final completionLevel = CompletionLevel.find(
+        completionState.args,
+        runner.argParser,
+        runner.commands,
+      );
+
+      // Do not complete if the command structure is not recognized
+      if (completionLevel == null) {
+        return null;
+      }
+
+      // Parse the completion level into completion suggestions
+      final completionResults = CompletionParser(
+        completionLevel: completionLevel,
+      ).parse();
 
-      runner.renderCompletionResult(result);
+      // Render the completion suggestions
+      for (final completionResult in completionResults) {
+        runner.renderCompletionResult(completionResult);
+      }
     } on Exception {
       // Do not output any Exception here, since even error messages are
       // interpreted as completion suggestions

lib/src/command_runner/completion_command_runner.dart

@@ -23,7 +23,7 @@ import 'package:meta/meta.dart';
 abstract class CompletionCommandRunner<T> extends CommandRunner<T> {
   /// {@macro completion_command_runner}
   CompletionCommandRunner(super.executableName, super.description) {
-    addCommand(HandleCompletionRequestCommand<T>(completionLogger));
+    addCommand(HandleCompletionRequestCommand<T>());
     addCommand(InstallCompletionFilesCommand<T>());
   }
 
@@ -93,6 +93,23 @@ abstract class CompletionCommandRunner<T> extends CommandRunner<T> {
     if (systemShell == null) {
       return;
     }
-    completionResult.render(completionLogger, systemShell);
+
+    for (final entry in completionResult.completions.entries) {
+      switch (systemShell) {
+        case SystemShell.zsh:
+          // On zsh, colon acts as delimitation between a suggestion and its
+          // description. Any literal colon should be escaped.
+          final suggestion = entry.key.replaceAll(':', r'\:');
+          final description = entry.value?.replaceAll(':', r'\:');
+
+          completionLogger.info(
+            '$suggestion${description != null ? ':$description' : ''}',
+          );
+          break;
+        case SystemShell.bash:
+          completionLogger.info(entry.key);
+          break;
+      }
+    }
   }
 }