test: add jest config and tests on locked code

FixJSDOMEnvironment.js

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+import { TestEnvironment } from 'jest-environment-jsdom'
+
+class FixJSDOMEnvironment extends TestEnvironment {
+  constructor(...args) {
+    super(...args);
+
+    // FIXME https://github.com/jsdom/jsdom/issues/3363
+    this.global.structuredClone = structuredClone;
+  }
+}
+
+// https://github.com/facebook/jest/blob/v29.4.3/website/versioned_docs/version-29.4/Configuration.md#testenvironment-string
+export default FixJSDOMEnvironment

babel.test.config.cjs

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+module.exports = {
+  plugins: [
+    ['@babel/plugin-transform-modules-commonjs', {
+      importInterop: 'babel'
+    }],
+    'babel-plugin-transform-import-meta'
+  ],
+  presets: [
+    '@babel/preset-env',
+    '@babel/preset-typescript'
+  ]
+}

browserMock.js

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+/* eslint-disable no-undef */
+/* eslint-disable @typescript-eslint/no-useless-constructor */
+/* eslint-disable @typescript-eslint/no-unused-vars */
+import { fetch as fetchPolyfill } from 'whatwg-fetch'
+import fs from 'fs/promises'
+import { performance } from 'perf_hooks'
+
+Object.defineProperty(document, 'queryCommandSupported', {
+  value: jest.fn().mockImplementation(() => true)
+})
+
+window.process = undefined
+
+Object.defineProperty(window, 'matchMedia', {
+  writable: true,
+  value: jest.fn().mockImplementation(query => ({
+    matches: false,
+    media: query,
+    onchange: null,
+    addListener: jest.fn(), // Deprecated
+    removeListener: jest.fn(), // Deprecated
+    addEventListener: jest.fn(),
+    removeEventListener: jest.fn(),
+    dispatchEvent: jest.fn()
+  }))
+})
+
+Object.defineProperty(window, 'fetch', {
+  value: jest.fn(async (url, options) => {
+    // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
+    if (url.startsWith('file:')) {
+      const content = await fs.readFile(new URL(url).pathname)
+      return {
+        json: async () => JSON.stringify(JSON.parse(content.toString())),
+        arrayBuffer: async () => content.buffer.slice(content.byteOffset, content.byteOffset + content.byteLength),
+        status: 200
+      }
+    } else {
+      return fetchPolyfill(url, options)
+    }
+  })
+})
+
+Object.defineProperty(URL, 'createObjectURL', {
+  value: jest.fn((blob) => {
+    return 'blob:not-working'
+  })
+})
+
+Object.defineProperty(window, 'Worker', {
+  value: class Worker {
+    constructor (stringUrl) {}
+    postMessage (msg) {}
+    terminate () {}
+    removeEventListener () {}
+  }
+})
+
+Object.defineProperty(window, 'ResizeObserver', {
+  value: class ResizeObserver {
+    constructor (stringUrl) {}
+    observe () {}
+  }
+})
+
+// These 2 classes come from https://gist.github.com/Yaffle/5458286
+Object.defineProperty(window, 'TextEncoder', {
+  value: class TextEncoder {
+    encode (string) {
+      const octets = []
+      const length = string.length
+      let i = 0
+      while (i < length) {
+        const codePoint = string.codePointAt(i)
+        let c = 0
+        let bits = 0
+        if (codePoint <= 0x0000007F) {
+          c = 0
+          bits = 0x00
+        } else if (codePoint <= 0x000007FF) {
+          c = 6
+          bits = 0xC0
+        } else if (codePoint <= 0x0000FFFF) {
+          c = 12
+          bits = 0xE0
+        } else if (codePoint <= 0x001FFFFF) {
+          c = 18
+          bits = 0xF0
+        }
+        octets.push(bits | (codePoint >> c))
+        c -= 6
+        while (c >= 0) {
+          octets.push(0x80 | ((codePoint >> c) & 0x3F))
+          c -= 6
+        }
+        i += codePoint >= 0x10000 ? 2 : 1
+      }
+      return Uint8Array.from(octets)
+    }
+  }
+})
+Object.defineProperty(window, 'TextDecoder', {
+  value: class TextDecoder {
+    decode (octets) {
+      if (octets == null) {
+        return ''
+      }
+      let string = ''
+      let i = 0
+      while (i < octets.length) {
+        let octet = octets[i]
+        let bytesNeeded = 0
+        let codePoint = 0
+        if (octet <= 0x7F) {
+          bytesNeeded = 0
+          codePoint = octet & 0xFF
+        } else if (octet <= 0xDF) {
+          bytesNeeded = 1
+          codePoint = octet & 0x1F
+        } else if (octet <= 0xEF) {
+          bytesNeeded = 2
+          codePoint = octet & 0x0F
+        } else if (octet <= 0xF4) {
+          bytesNeeded = 3
+          codePoint = octet & 0x07
+        }
+        if (octets.length - i - bytesNeeded > 0) {
+          let k = 0
+          while (k < bytesNeeded) {
+            octet = octets[i + k + 1]
+            codePoint = (codePoint << 6) | (octet & 0x3F)
+            k += 1
+          }
+        } else {
+          codePoint = 0xFFFD
+          bytesNeeded = octets.length - i
+        }
+        string += String.fromCodePoint(codePoint)
+        i += bytesNeeded + 1
+      }
+      return string
+    }
+  }
+})
+
+Object.defineProperty(window, 'Buffer', {
+  value: undefined
+})
+
+// Force override performance, for some reason the implementation is empty otherwise
+const _performance = performance
+Object.defineProperty(global, 'performance', {
+  get () { return _performance },
+  set (v) {
+    // ignore
+  }
+})
+
+global.CSS = {
+  escape: v => v
+}
+
+Element.prototype.scrollIntoView = jest.fn()

jest/cssTransform.cjs

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+'use strict'
+
+// This is a custom Jest transformer turning style imports into empty objects.
+// http://facebook.github.io/jest/docs/en/webpack.html
+
+module.exports = {
+  process () {
+    return { code: 'module.exports = {};' }
+  },
+  getCacheKey () {
+    // The output is always the same.
+    return 'cssTransform'
+  }
+}

jest/fileTransform.cjs

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+module.exports = {
+  process(src, filename) {
+    const assetFilename = JSON.stringify(filename);
+
+    return { code: `module.exports = ${assetFilename};` };
+  },
+};

jest/resolver.cjs

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+const browserResolve = require('browser-resolve')
+
+module.exports = (path, options) => {
+  try {
+    return browserResolve.sync(path, options)
+  } catch (error) {
+    return options.defaultResolver(path, options)
+  }
+}