fix(args): honor explicit value on boolean flags (--flag=false)

parseFlags set a boolean flag to `true` as soon as it matched the flag,
before inspecting an inline `=value`. So `--flag=false` (or `--flag=0`)
was silently set to `true` -- the opposite of what the user typed -- and
the value was discarded.

Honor an explicit value: `--flag=false`/`0`/`no`/`off` -> false; a bare
`--flag` and `--flag=true` (or any other value) stay true, so there is no
behavior change for existing usage.

Adds parseFlags tests for the bare-flag and explicit-value cases.

Author: Osamaali313

src/args.ts

@@ -114,7 +114,12 @@ export function parseFlags(argv: string[], options: OptionDef[]): GlobalFlags {
       const camelKey = kebabToCamel(key);
 
       if (schema.booleans.has(camelKey)) {
-        (flags as Record<string, unknown>)[camelKey] = true;
+        // A bare boolean flag (`--flag`) is true. Honour an explicit value
+        // such as `--flag=false` / `--flag=0` instead of silently forcing the
+        // flag to true and discarding what the user typed.
+        (flags as Record<string, unknown>)[camelKey] =
+          value === undefined ||
+          !['false', '0', 'no', 'off'].includes(value.trim().toLowerCase());
         i++;
         continue;
       }

test/args.test.ts

@@ -5,6 +5,7 @@ import type { OptionDef } from '../src/command';
 const OPTIONS: OptionDef[] = [
   { flag: '--timeout <seconds>', description: 'Request timeout', type: 'number' },
   { flag: '--message <text>', description: 'Message text', type: 'array' },
+  { flag: '--verbose', description: 'Verbose output' },
 ];
 
 describe('parseFlags', () => {
@@ -25,4 +26,15 @@ describe('parseFlags', () => {
 
     expect(flags.timeout).toBe(1.5);
   });
+
+  it('treats a bare boolean flag as true', () => {
+    expect(parseFlags(['--verbose'], OPTIONS).verbose).toBe(true);
+  });
+
+  it('honours an explicit value on a boolean flag instead of forcing true', () => {
+    // Regression: `--flag=false` / `--flag=0` were silently set to true.
+    expect(parseFlags(['--verbose=false'], OPTIONS).verbose).toBe(false);
+    expect(parseFlags(['--verbose=0'], OPTIONS).verbose).toBe(false);
+    expect(parseFlags(['--verbose=true'], OPTIONS).verbose).toBe(true);
+  });
 });