"Maximum call stack size exceeded" for assert.fixture()

One of my fixture tests fails because of a Maximum call stack size exceeded error.

OS: MacOS 11.4 Node: v14.15.3 uvu: 0.5.1

// json => readFileSync()
assert.fixture(JSON.stringify(analyze(css), null, 2), json)

This JSON is a 15.000+ lines file.

Workaround

To avoid adding the arr.map() callback to the call stack for every line (15.000+) I’m using a for-loop.

+ // https://github.com/lukeed/uvu/blob/1d753576ffab2dd28b309bb5c296a43d0800321c/src/assert.js#L4-L8
-function dedent(str) {
-	let arr = str.match(/^[ \t]*(?=\S)/gm);
-	let min = !!arr && Math.min(...arr.map(x => x.length));
-	return (!arr || !min) ? str : str.replace(new RegExp(`^[ \\t]{${min}}`, 'gm'), '');
-}
+function dedent(str) {
+	let arr = str.match(/^[ \t]*(?=\S)/gm);
+	if (!Array.isArray(arr) || arr.length === 0) {
+		return str
+	}
+	let min = -1
+       // Workaround for arr.map() to avoid add each map(fn) to call stack
+	for (let index = 0; index < arr.length; index++) {
+		const el = arr[index].length
+		if (el > min) {
+			min = el
+		}
+	}
+	return (!min) ? str : str.replace(new RegExp(`^[ \\t]{${min}}`, 'gm'), '');
+}

Happy to submit a PR if you think this is a suitable solution and worth fixing.

[lukeed]

Ha, literally the one time I use newer syntax instead of a for-loop 🤦

PR would be great! How about this instead, which is only slightly modified & should still work:

function dedent(str) {
  let arr = str.match(/^[ \t]*(?=\S)/gm);
  let i = 0, min = 1/0, len = (arr||[]).length;
  for (; i < len; i++) min = Math.min(min, arr[i].length);
  return len && min ? str.replace(new RegExp(`^[ \\t]{${min}}`, 'gm'), '') : str;
}

Thanks!

[lukeed]

Ah ok cool, thanks! 😃