feat: make install command the default when no arguments provided

Changes:
- When running commit-msg without arguments, automatically run the
  install command instead of showing help
- Updated README.md to document this behavior
- Updated tests to reflect the new behavior

This makes it easier for users to install the hook by simply running
`npx commit-msg` without any arguments.

Change-Id: I8593343a0f4080c4c6554b0920254cd1f4a8561e
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>

Author: jiangxin

README.md

@@ -31,6 +31,14 @@ npx commit-msg install
 This will install the commit-msg hook in your repository's `.git/hooks` directory,
 or in the hook path defined by `core.hooksPath` config variables.
 
+If you run `commit-msg` without any arguments, it will automatically run the `install` command:
+
+```bash
+npx commit-msg
+```
+
+This is equivalent to running `npx commit-msg install`.
+
 ### Development
 
 For development, you can run the tool directly with ts-node:
@@ -83,6 +91,8 @@ When building the project, only the production files are compiled to the `dist`
 - `install` - Install the commit-msg hook in the current Git repository
 - `exec` - Execute the commit-msg hook logic (used internally by the hook)
 
+If no command is specified, the `install` command will be run by default.
+
 ## Configuration
 
 The tool follows these Git configuration options:

src/bin/commit-msg.dev.ts

@@ -203,14 +203,16 @@ async function main() {
       }
     });
 
-  // Add default command to handle commit message file directly
+  // Add default command to handle commit message file directly or run install when no args
   program
     .description('CLI tool for managing Git commit-msg hooks')
     .arguments('[message-file]')
     .action(async (messageFile, options) => {
-      // If no message file is provided, show help
+      const verbose = getVerboseMode({ ...program.opts(), ...options });
+
+      // If no message file is provided, run install command
       if (!messageFile) {
-        program.help();
+        await handleInstallCommand(verbose, install, checkAndUpgrade);
         return;
       }
 
@@ -220,7 +222,6 @@ async function main() {
         throw new CleanError(`Command or file not found: ${messageFile}`);
       }
 
-      const verbose = getVerboseMode({ ...program.opts(), ...options });
       await handleExecCommand(messageFile, verbose, exec, checkAndUpgrade);
     });
 

src/bin/commit-msg.ts

@@ -203,14 +203,16 @@ async function main() {
       }
     });
 
-  // Add default command to handle commit message file directly
+  // Add default command to handle commit message file directly or run install when no args
   program
     .description('CLI tool for managing Git commit-msg hooks')
     .arguments('[message-file]')
     .action(async (messageFile, options) => {
-      // If no message file is provided, show help
+      const verbose = getVerboseMode({ ...program.opts(), ...options });
+
+      // If no message file is provided, run install command
       if (!messageFile) {
-        program.help();
+        await handleInstallCommand(verbose, install, checkAndUpgrade);
         return;
       }
 
@@ -220,7 +222,6 @@ async function main() {
         throw new CleanError(`Command or file not found: ${messageFile}`);
       }
 
-      const verbose = getVerboseMode({ ...program.opts(), ...options });
       await handleExecCommand(messageFile, verbose, exec, checkAndUpgrade);
     });
 

test/direct-hook.test.ts

@@ -87,7 +87,7 @@ describe('direct commit-msg hook execution tests', () => {
       );
     });
 
-    it('should show help when executed without arguments', () => {
+    it('should run install command when executed without arguments', () => {
       // Execute commit-msg directly without arguments
       const result = spawnSync(
         'node',
@@ -100,9 +100,9 @@ describe('direct commit-msg hook execution tests', () => {
       );
 
       expect(result.status).toBe(0);
-      expect(result.stdout).toContain('Usage: commit-msg');
+      expect(result.stdout).toContain('Installing commit-msg hook...');
       expect(result.stdout).toContain(
-        'CLI tool for managing Git commit-msg hooks'
+        'Commit-msg hook installed successfully!'
       );
     });