#353·wtfjs

CLI crashes on launch with `TypeError: meow is not a function` due to ESM/CJS mismatch

Author: codeCraft-RitikCreated Sep 14, 2026Updated Sep 14, 2026

Issue : CLI crashes on launch with `TypeError: meow is not a function` due to ESM/CJS mismatch

Severity & Impact

Severity: Critical / Blocker
Impact: The executable CLI binary (wtfjs) crashes immediately upon execution. Any user who installs wtfjs globally via npm install -g wtfjs and runs wtfjs is greeted with a fatal crash. The package's core executable functionality is completely broken.

Affected Files

wtfjs.js (Line 8–14)
package.json (Dependencies)

Root Cause Analysis

In package.json, several dependencies were bumped to major versions that are pure ES Modules (ESM):

"meow": "^10.1.4" (v10+ is ESM-only)
"chalk": "^5.0.1" (v5+ is ESM-only)
"boxen": "^7.0.0" (v7+ is ESM-only)
"update-notifier": "^6.0.2" (v6+ is ESM-only)

However, package.json does not specify "type": "module", and wtfjs.js still uses CommonJS:

javascript

const boxen = require("boxen");
const chalk = require("chalk");
const updateNotifier = require("update-notifier");
const pkg = require("./package.json");
const meow = require("meow");

const cli = meow(...);

On Node < 22 (e.g. Node 16, 18, 20): Node throws Error [ERR_REQUIRE_ESM]: require() of ES Module ... not supported.
On Node 22+: Node's CJS loader loads the ESM module as a namespace object ({ __esModule: true, default: [Function: meow] }). Consequently, const meow = require("meow") assigns the namespace object, and invoking meow(...) immediately throws:
```
TypeError: meow is not a function
```

The same issue applies to updateNotifier and boxen.

Minimal Reproducible Example

bash

$ node wtfjs.js

Actual Output

C:\Users\...\wtfjs\wtfjs.js:14
const cli = meow(
            ^

TypeError: meow is not a function
    at Object.<anonymous> (C:\Users\...\wtfjs\wtfjs.js:14:13)

Expected Output

The CLI runs smoothly, parses arguments, and pipes the manual into the pager.

Proposed Fix

There are two recommended approaches:

Option A: Modernize `wtfjs.js` to pure ESM (Recommended)

Add "type": "module" to package.json and convert wtfjs.js to use import:

diff

--- a/package.json
+++ b/package.json
@@ -3,4 +3,5 @@
   "version": "1.22.8",
+  "type": "module",
   "description": "A list of funny and tricky JavaScript examples",

diff

--- a/wtfjs.js
+++ b/wtfjs.js
@@ -1,13 +1,15 @@
 #!/usr/bin/env node
 
-const fs = require("fs");
-const obj = require("through2").obj;
-const pager = require("default-pager");
-const msee = require("msee");
-const join = require("path").join;
-const boxen = require("boxen");
-const chalk = require("chalk");
-const updateNotifier = require("update-notifier");
-const pkg = require("./package.json");
-const meow = require("meow");
+import fs from "node:fs";
+import { createRequire } from "node:module";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+import boxen from "boxen";
+import chalk from "chalk";
+import pager from "default-pager";
+import meow from "meow";
+import msee from "msee";
+import updateNotifier from "update-notifier";
+
+const require = createRequire(import.meta.url);
+const pkg = require("./package.json");
+const __dirname = dirname(fileURLToPath(import.meta.url));

Option B: Revert dependencies to CommonJS versions

Pin dependencies to their latest CommonJS releases:

json

"dependencies": {
  "boxen": "^5.1.2",
  "chalk": "^4.1.2",
  "default-pager": "^1.1.0",
  "meow": "^9.0.0",
  "msee": "^0.3.3",
  "through2": "^4.0.2",
  "update-notifier": "^5.1.0"
}

Source: denysdovhan/wtfjs

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