Fix: Print help instead of throwing error on unknown commands

original_program.ts

@@ -0,0 +1,17 @@
+// ... (skip down to line 179)
+  program.on('command:*', async function (this: Command, op) {
+    const msg = intl.formatMessage(
+      {
+        defaultMessage: 'Unknown command "clasp {command}"',
+      },
+      {
+        command: op[0],
+      },
+    );
+    this.error(msg as string);
+  });
+
+  program.error;
+
+  return program;
+}

src/commands/program.ts

@@ -179,7 +179,7 @@ export function makeProgram(exitOverride?: (err: CommanderError) => void) {
     cmd.copyInheritedSettings(program);
   }
 
-  program.on('command:*', async function (this: Command, op) {
+  program.on('command:*', function (this: Command, op) {
     const msg = intl.formatMessage(
       {
         defaultMessage: 'Unknown command "clasp {command}"',
@@ -188,10 +188,10 @@ export function makeProgram(exitOverride?: (err: CommanderError) => void) {
         command: op[0],
       },
     );
-    this.error(msg as string);
+    console.error(msg as string);
+    process.exitCode = 1;
+    program.help();
   });
 
-  program.error;
-
   return program;
 }

src/core/clasp.ts

@@ -203,7 +203,8 @@ export async function initClaspInstance(options: InitOptions): Promise<Clasp> {
   const rootDirReal = await fs.realpath(projectRoot.rootDir).catch(() => projectRoot.rootDir);
 
   // Strict validation: resolved path must be rootDir or properly inside it
-  const isValid = contentDir === projectRoot.rootDir ||
+  const isValid =
+    contentDir === projectRoot.rootDir ||
     (contentDir.startsWith(rootDirReal + path.sep) && isInside(projectRoot.rootDir, contentDir));
 
   if (!isValid) {

test/commands/program.ts

@@ -19,6 +19,7 @@ import {expect} from 'chai';
 import {describe, it} from 'mocha';
 
 import {makeProgram} from '../../src/commands/program.js';
+import {runCommand} from './utils.js';
 
 describe('Consistency between imported and registered commands', () => {
   const expectedCommands = [
@@ -67,3 +68,16 @@ describe('Consistency between imported and registered commands', () => {
     expect(program.commands).to.length(expectedCommands.length);
   });
 });
+
+describe('Unknown commands', () => {
+  it('should print help when an unknown command is provided', async () => {
+    const result = await runCommand(['nonexistentcommand'], false);
+
+    expect(result.stderr).to.contain('Unknown command "clasp nonexistentcommand"');
+    expect(result.stdout).to.contain('Usage: clasp <command> [options]');
+
+    // Also the global process.exitCode should be set to 1 by our patch
+    expect(process.exitCode).to.equal(1);
+    process.exitCode = 0; // reset for subsequent tests
+  });
+});