feat: add --json flag to list scripts in json format (#953)

<!--
  Thanks for contributing!

Provide a description of your changes below and a general summary in the
title

Please look at the following checklist to ensure that your PR can be
accepted quickly:
-->

Closes #435 

## Description

Adds a --json flag to the run command that makes it possible to list all
scripts defined in the melos workspace config in json format. This flag
only works in combination with the --list flag and if no script name is
defined.

Added --list and --json to the documentation

## Type of Change

<!--- Put an `x` in all the boxes that apply: -->

- [x] ✨ `feat` -- New feature (non-breaking change which adds
functionality)
- [ ] 🛠️ `fix` -- Bug fix (non-breaking change which fixes an issue)
- [ ] ❌ `!` -- Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] 🧹 `refactor` -- Code refactor
- [ ] ✅ `ci` -- Build configuration change
- [x] 📝 `docs` -- Documentation
- [ ] 🗑️ `chore` -- Chore

Author: ARau87

docs/commands/run.mdx

@@ -21,3 +21,18 @@ applied.
 ```bash
 melos run <name> --no-select
 ```
+
+## --list
+
+Displays all scripts defined in the Melos workspace.
+
+```bash
+melos run --list
+```
+
+Use `--json` to output the list in JSON format.
+
+```bash
+melos run --list --json
+```
+

packages/melos/lib/src/command_runner/run.dart

@@ -16,6 +16,14 @@ class RunCommand extends MelosCommand {
       negatable: false,
       help: 'Lists all scripts defined in the melos.yaml config file.',
     );
+
+    argParser.addFlag(
+      'json',
+      negatable: false,
+      help:
+          'Lists all scripts defined in the melos.yaml config file with '
+          'description in json format.',
+    );
   }
 
   @override
@@ -38,6 +46,7 @@ class RunCommand extends MelosCommand {
         ? argResults!.rest.skip(1).toList()
         : <String>[];
     final listScripts = argResults!['list'] as bool;
+    final listScriptsAsJson = argResults!['json'] as bool;
 
     try {
       return await melos.run(
@@ -46,6 +55,7 @@ class RunCommand extends MelosCommand {
         noSelect: noSelect,
         extraArgs: extraArgs,
         listScripts: listScripts,
+        listScriptsAsJson: listScriptsAsJson,
       );
     } on NoPackageFoundScriptException catch (err) {
       logger.warning(err.toString(), label: false);

packages/melos/lib/src/commands/run.dart

@@ -7,14 +7,14 @@ mixin _RunMixin on _Melos {
     String? scriptName,
     bool noSelect = false,
     bool listScripts = false,
+    bool listScriptsAsJson = false,
     List<String> extraArgs = const [],
   }) async {
     if (listScripts && scriptName == null) {
-      logger.command('melos run --list');
-      logger.newLine();
-      config.scripts.forEach((_, script) => logger.log(script.name));
+      _handleListScripts(listAsJson: listScriptsAsJson);
       return;
     }
+
     if (config.scripts.keys.isEmpty) {
       throw NoScriptException._();
     }
@@ -91,6 +91,18 @@ mixin _RunMixin on _Melos {
     }
   }
 
+  void _handleListScripts({bool listAsJson = false}) {
+    if (listAsJson) {
+      logger.command('melos run --list --json');
+      logger.newLine();
+      logger.log(json.encode(config.scripts));
+    } else {
+      logger.command('melos run --list');
+      logger.newLine();
+      config.scripts.forEach((_, script) => logger.log(script.name));
+    }
+  }
+
   /// Detects recursive script calls within the provided [script].
   ///
   /// This method recursively traverses the steps of the script to check

packages/melos/test/commands/run_test.dart

@@ -968,5 +968,67 @@ SUCCESS
         );
       },
     );
+
+    test(
+      'verifies that the --list flag in combination with '
+      '--json lists all scripts in the config in json format',
+      () async {
+        final workspaceDir = await createTemporaryWorkspace(
+          configBuilder: (path) => MelosWorkspaceConfig(
+            path: path,
+            name: 'test_package',
+            packages: [
+              createGlob('packages/**', currentDirectoryPath: path),
+            ],
+            scripts: const Scripts({
+              'test_script_1': Script(
+                name: 'test_script',
+                steps: [
+                  'absolute_bogus_command',
+                  'echo "test_script_2"',
+                ],
+              ),
+              'test_script_2': Script(
+                name: 'test_script',
+                steps: [
+                  'absolute_bogus_command',
+                  'echo "test_script_2"',
+                ],
+              ),
+              'test_script_3': Script(
+                name: 'test_script',
+                steps: [
+                  'absolute_bogus_command',
+                  'echo "test_script_2"',
+                ],
+              ),
+            }),
+          ),
+          workspacePackages: ['a'],
+        );
+
+        await createProject(workspaceDir, Pubspec('a'));
+
+        final logger = TestLogger();
+        final config = await MelosWorkspaceConfig.fromWorkspaceRoot(
+          workspaceDir,
+        );
+        final melos = Melos(
+          logger: logger,
+          config: config,
+        );
+
+        await melos.run(listScripts: true, listScriptsAsJson: true);
+
+        expect(
+          logger.output.normalizeLines().split('\n'),
+          containsAllInOrder([
+            'melos run --list --json',
+            '',
+            r'{"test_script_1":{"name":"test_script_1","run":null,"steps":["absolute_bogus_command","echo \"test_script_2\""]},"test_script_2":{"name":"test_script_2","run":null,"steps":["absolute_bogus_command","echo \"test_script_2\""]},"test_script_3":{"name":"test_script_3","run":null,"steps":["absolute_bogus_command","echo \"test_script_2\""]}}',
+          ]),
+        );
+      },
+    );
   });
 }