feat: Add illegal flag verification

packages/cli/src/args.ts

@@ -25,6 +25,15 @@ interface FlagSchema {
   arrays: Set<string>;
 }
 
+function buildAllowedFlagKeys(options: OptionDef[]): Set<string> {
+  const keys = new Set<string>();
+  for (const opt of options) {
+    const key = flagKey(opt);
+    if (key) keys.add(key);
+  }
+  return keys;
+}
+
 function buildSchema(options: OptionDef[]): FlagSchema {
   const booleans = new Set<string>();
   const numbers = new Set<string>();
@@ -91,6 +100,7 @@ export function scanCommandPath(argv: string[], globalOptions: OptionDef[] = [])
  *   - default: string
  */
 export function parseFlags(argv: string[], options: OptionDef[]): GlobalFlags {
+  const allowedKeys = buildAllowedFlagKeys(options);
   const schema = buildSchema(options);
   const flags: GlobalFlags = {
     quiet: false,
@@ -130,6 +140,13 @@ export function parseFlags(argv: string[], options: OptionDef[]): GlobalFlags {
 
       const camelKey = kebabToCamel(key);
 
+      if (!allowedKeys.has(camelKey)) {
+        throw new BailianError(
+          `Unknown flag "--${key}". Run with --help to see available options.`,
+          ExitCode.USAGE,
+        );
+      }
+
       if (schema.booleans.has(camelKey)) {
         (flags as Record<string, unknown>)[camelKey] = true;
         i++;

packages/cli/tests/args.test.ts

@@ -0,0 +1,40 @@
+import { expect, test } from "vite-plus/test";
+import { ExitCode, GLOBAL_OPTIONS } from "bailian-cli-core";
+import { parseFlags } from "../src/args.ts";
+
+const IMAGE_GENERATE_OPTIONS = [
+  { flag: "--prompt <text>", description: "Image description", required: true },
+  { flag: "--model <model>", description: "Model ID" },
+  { flag: "--watermark <bool>", description: "Enable watermark (true/false). Default: true." },
+];
+
+test("parseFlags rejects unknown long flags", () => {
+  expect(() =>
+    parseFlags(["--prompt", "cat", "--xxxx", "a"], [...GLOBAL_OPTIONS, ...IMAGE_GENERATE_OPTIONS]),
+  ).toThrowError(
+    expect.objectContaining({
+      name: "BailianError",
+      exitCode: ExitCode.USAGE,
+      message: expect.stringContaining('Unknown flag "--xxxx"'),
+    }),
+  );
+});
+
+test("parseFlags rejects unknown flags with = syntax", () => {
+  expect(() =>
+    parseFlags(
+      ["--prompt=cat", "--unknown-flag=yes"],
+      [...GLOBAL_OPTIONS, ...IMAGE_GENERATE_OPTIONS],
+    ),
+  ).toThrow(/Unknown flag "--unknown-flag"/);
+});
+
+test("parseFlags accepts defined command and global flags", () => {
+  const flags = parseFlags(
+    ["--quiet", "--prompt", "cat", "--watermark", "false"],
+    [...GLOBAL_OPTIONS, ...IMAGE_GENERATE_OPTIONS],
+  );
+  expect(flags.quiet).toBe(true);
+  expect(flags.prompt).toBe("cat");
+  expect(flags.watermark).toBe("false");
+});