second commit

node_modules/@pkgjs/parseargs/examples/ordered-options.mjs

@@ -0,0 +1,41 @@
+// This is an example of using tokens to add a custom behaviour.
+//
+// This adds a option order check so that --some-unstable-option
+// may only be used after --enable-experimental-options
+//
+// Note: this is not a common behaviour, the order of different options
+// does not usually matter.
+
+import { parseArgs } from '../index.js';
+
+function findTokenIndex(tokens, target) {
+  return tokens.findIndex((token) => token.kind === 'option' &&
+    token.name === target
+  );
+}
+
+const experimentalName = 'enable-experimental-options';
+const unstableName = 'some-unstable-option';
+
+const options = {
+  [experimentalName]: { type: 'boolean' },
+  [unstableName]: { type: 'boolean' },
+};
+
+const { values, tokens } = parseArgs({ options, tokens: true });
+
+const experimentalIndex = findTokenIndex(tokens, experimentalName);
+const unstableIndex = findTokenIndex(tokens, unstableName);
+if (unstableIndex !== -1 &&
+  ((experimentalIndex === -1) || (unstableIndex < experimentalIndex))) {
+  throw new Error(`'--${experimentalName}' must be specified before '--${unstableName}'`);
+}
+
+console.log(values);
+
+/* eslint-disable max-len */
+// Try the following:
+//    node ordered-options.mjs
+//    node ordered-options.mjs --some-unstable-option
+//    node ordered-options.mjs --some-unstable-option --enable-experimental-options
+//    node ordered-options.mjs --enable-experimental-options --some-unstable-option