add failing test

Author: AmirSa12

tests/completion-exec.test.ts

@@ -0,0 +1,77 @@
+import { exec } from 'node:child_process';
+import { describe, it, expect } from 'vitest';
+
+// Verifies the command that generated completion scripts invoke to request
+// suggestions. Completion is triggered by the shell only once the command name
+// is resolvable (via PATH, an alias, or a shell function), so the script should
+// invoke the CLI by its plain program name rather than a reconstructed,
+// runtime-specific launch path. Baking in a launch path makes the script
+// depend on how the CLI happened to be started, which does not hold across
+// runtimes (e.g. compiled single-file binaries).
+
+function run(command: string): Promise<string> {
+  return new Promise((resolve, reject) => {
+    exec(command, { cwd: process.cwd() }, (error, stdout, stderr) => {
+      if (error) reject(new Error(stderr || String(error)));
+      else resolve(stdout);
+    });
+  });
+}
+
+// Pull out the command the generated script will exec to request completions
+// (the value baked in as `requestComp` / `$RequestComp`), across every shell.
+function extractExecCommand(shell: string, script: string): string | null {
+  let match: RegExpMatchArray | null = null;
+  switch (shell) {
+    case 'zsh':
+    case 'bash':
+      match = script.match(/requestComp="(.+?) complete --/);
+      break;
+    case 'fish':
+      match = script.match(/set -l requestComp "(.+?) complete --/);
+      break;
+    case 'powershell':
+      match = script.match(/\$RequestComp = "& (.+?) complete '--'/);
+      break;
+  }
+  return match ? match[1] : null;
+}
+
+const adapters = [
+  { adapter: 'commander', programName: 'myapp' },
+  { adapter: 'cac', programName: 'vite' },
+  { adapter: 'citty', programName: 'vite' },
+] as const;
+
+const shells = ['zsh', 'bash', 'fish', 'powershell'] as const;
+
+describe('generated completion scripts invoke the CLI by program name', () => {
+  for (const { adapter, programName } of adapters) {
+    describe(`${adapter} adapter`, () => {
+      for (const shell of shells) {
+        it(`${shell}: requestComp uses the program name, not a runtime launch path`, async () => {
+          const script = await run(
+            `pnpm tsx examples/demo.${adapter}.ts complete ${shell}`
+          );
+
+          const execCommand = extractExecCommand(shell, script);
+          expect(
+            execCommand,
+            `could not locate requestComp in generated ${shell} script`
+          ).not.toBeNull();
+
+          // The command baked into the script must be exactly the program name.
+          expect(execCommand).toBe(programName);
+
+          // A bare program name never contains any of these substrings, so
+          // their presence signals a runtime-specific launch path leaking in.
+          expect(execCommand).not.toContain('/');
+          expect(execCommand).not.toContain('node');
+          expect(execCommand).not.toContain('tsx');
+          expect(execCommand).not.toContain('$bunfs');
+          expect(execCommand).not.toContain('.ts');
+        });
+      }
+    });
+  }
+});