modernize, switch to ESM, GH Actions, ESLint 9+

.github/workflows/node.yml

@@ -0,0 +1,22 @@
+name: Node
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Setup Node
+      uses: actions/setup-node@v1
+      with:
+        node-version: 18
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Run tests
+      run: npm test
+
+    - name: Run the CLI tool
+      run: node bin/pixelmatch test/fixtures/1a.png test/fixtures/1b.png

bin/pixelmatch

@@ -1,11 +1,8 @@
 #!/usr/bin/env node
-/* eslint-disable no-process-exit */
 
-'use strict';
-
-const PNG = require('pngjs').PNG;
-const fs = require('fs');
-const match = require('../.');
+import {PNG} from 'pngjs';
+import fs from 'fs';
+import match from '../index.js';
 
 if (process.argv.length < 4) {
     console.log('Usage: pixelmatch image1.png image2.png [diff.png] [threshold] [includeAA]');

eslint.config.js

@@ -0,0 +1,8 @@
+import config from 'eslint-config-mourner';
+
+export default [
+    ...config,
+    {
+        files: ['*.js', 'test/test.js', 'bin/pixelmatch']
+    }
+];

index.js

@@ -1,6 +1,3 @@
-'use strict';
-
-module.exports = pixelmatch;
 
 const defaultOptions = {
     threshold: 0.1,         // matching threshold (0 to 1); smaller is more sensitive
@@ -12,7 +9,7 @@ const defaultOptions = {
     diffMask: false         // draw the diff over a transparent background (a mask)
 };
 
-function pixelmatch(img1, img2, output, width, height, options) {
+export default function pixelmatch(img1, img2, output, width, height, options) {
 
     if (!isPixelData(img1) || !isPixelData(img2) || (output && !isPixelData(output)))
         throw new Error('Image data: Uint8Array, Uint8ClampedArray or Buffer expected.');