doc: refine sample code on tokens of util/parseArgs

Author: imcotton

doc/api/util.md

@@ -1518,25 +1518,22 @@ const options = {
   'logfile': { type: 'string' },
   'no-logfile': { type: 'boolean' },
 };
-const { values, tokens } = parseArgs({ options, tokens: true });
+const { values, tokens = [] } = parseArgs({ options, tokens: true });
 
 // Reprocess the option tokens and overwrite the returned values.
-tokens
-  .filter((token) => token.kind === 'option')
-  .forEach((token) => {
-    if (token.name.startsWith('no-')) {
-      // Store foo:false for --no-foo
-      const positiveName = token.name.slice(3);
-      values[positiveName] = false;
-      delete values[token.name];
-    } else {
-      // Resave value so last one wins if both --foo and --no-foo.
-      values[token.name] = token.value ?? true;
-    }
-  });
+const { color, logfile = 'default.log' } = tokens
+  .filter(({ kind }) => kind === 'option')
+  .reduce((acc, { name, value }) => {
+
+    const { [name]: _, ...rest } = acc;
+
+    const negate = name.startsWith('no-');
+    const k = negate ? name.slice(3) : name;
+    const v = negate ? false : (value ?? true);
+
+    return { ...rest, [k]: v };
 
-const color = values.color;
-const logfile = values.logfile ?? 'default.log';
+  }, values);
 
 console.log({ logfile, color });
 ```
@@ -1550,25 +1547,22 @@ const options = {
   'logfile': { type: 'string' },
   'no-logfile': { type: 'boolean' },
 };
-const { values, tokens } = parseArgs({ options, tokens: true });
+const { values, tokens = [] } = parseArgs({ options, tokens: true });
 
 // Reprocess the option tokens and overwrite the returned values.
-tokens
-  .filter((token) => token.kind === 'option')
-  .forEach((token) => {
-    if (token.name.startsWith('no-')) {
-      // Store foo:false for --no-foo
-      const positiveName = token.name.slice(3);
-      values[positiveName] = false;
-      delete values[token.name];
-    } else {
-      // Resave value so last one wins if both --foo and --no-foo.
-      values[token.name] = token.value ?? true;
-    }
-  });
+const { color, logfile = 'default.log' } = tokens
+  .filter(({ kind }) => kind === 'option')
+  .reduce((acc, { name, value }) => {
+
+    const { [name]: _, ...rest } = acc;
+
+    const negate = name.startsWith('no-');
+    const k = negate ? name.slice(3) : name;
+    const v = negate ? false : (value ?? true);
+
+    return { ...rest, [k]: v };
 
-const color = values.color;
-const logfile = values.logfile ?? 'default.log';
+  }, values);
 
 console.log({ logfile, color });
 ```