test(exoflex): make tests even FASTER, BLAZING FAST ⚡️ ⚡️ ⚡️

packages/exoflex/babel.config.js

@@ -1,3 +1,3 @@
 module.exports = {
-  presets: ['module:metro-react-native-babel-preset'],
+  presets: ['module:metro-react-native-babel-preset', '@babel/typescript'],
 };

packages/exoflex/jest.config.js

@@ -1,18 +1,6 @@
-const { defaults: tsjPreset } = require('ts-jest/presets');
-
 module.exports = {
-  ...tsjPreset,
   setupFiles: ['<rootDir>/test/modules-mock'],
   preset: './jestPresets/jest-preset',
-  transform: {
-    ...tsjPreset.transform,
-    '\\.js$': '<rootDir>/node_modules/react-native/jest/preprocessor.js',
-  },
-  globals: {
-    'ts-jest': {
-      babelConfig: true,
-    },
-  },
   modulePathIgnorePatterns: ['<rootDir>/lib/', '<rootDir>/example/'],
   transformIgnorePatterns: [
     'node_modules/(?!(react-native|react-native-paper|react-native-safe-area-view|react-native-animation-hooks|react-native-svg|react-native-calendars|react-native-multi-slider|react-native-collapsible|react-native-modal-datetime-picker|react-native-vector-icons)/)',

packages/exoflex/package.json

@@ -18,7 +18,8 @@
     "lint": "eslint --max-warnings 0 \"src/**/*.{ts,tsx}\"",
     "typecheck": "tsc --noEmit -p .",
     "jest": "jest --coverage --passWithNoTests",
-    "test": "yarn format:check && yarn lint && yarn typecheck && yarn jest"
+    "test": "yarn format:check && yarn lint && yarn typecheck && yarn jest",
+    "postinstall": "patch-package"
   },
   "peerDependencies": {
     "expo-font": "*",
@@ -36,6 +37,7 @@
     "react-native-paper": "^2.16.0"
   },
   "devDependencies": {
+    "@babel/preset-typescript": "^7.6.0",
     "@react-native-community/bob": "^0.6.1",
     "@testing-library/react": "^9.1.1",
     "@testing-library/react-hooks": "^2.0.3",
@@ -59,6 +61,8 @@
     "jest-watch-select-projects": "^1.0.0",
     "jest-watch-typeahead": "^0.4.0",
     "jest-with-platform": "^0.0.3",
+    "patch-package": "^6.2.0",
+    "postinstall-postinstall": "^2.0.0",
     "prettier": "^1.18.2",
     "react": "^16.9.0",
     "react-dom": "^16.9.0",
@@ -70,7 +74,6 @@
     "react-test-renderer": "^16.9.0",
     "regenerator-runtime": "^0.13.3",
     "release-it": "^12.3.6",
-    "ts-jest": "^24.0.2",
     "typescript": "^3.5.3"
   },
   "@react-native-community/bob": {

packages/exoflex/patches/@jest+transform+24.9.0.patch

@@ -0,0 +1,34 @@
+diff --git a/node_modules/@jest/transform/build/ScriptTransformer.js b/node_modules/@jest/transform/build/ScriptTransformer.js
+index 0dbc1d7..b595ec6 100644
+--- a/node_modules/@jest/transform/build/ScriptTransformer.js
++++ b/node_modules/@jest/transform/build/ScriptTransformer.js
+@@ -207,7 +207,7 @@ const _require = require('../package.json'),
+ // we need to transform a file. Since ScriptTransformer is instantiated for each
+ // file we need to keep this object in the local scope of this module.
+
+-const projectCaches = new WeakMap(); // To reset the cache for specific changesets (rather than package version).
++const projectCaches = new Map(); // To reset the cache for specific changesets (rather than package version).
+
+ const CACHE_VERSION = '1';
+
+@@ -239,16 +239,17 @@ class ScriptTransformer {
+     this._config = config;
+     this._transformCache = new Map();
+     this._transformConfigCache = new Map();
+-    let projectCache = projectCaches.get(config);
++    const configString = (0, _fastJsonStableStringify().default)(this._config);
++    let projectCache = projectCaches.get(configString);
+
+     if (!projectCache) {
+       projectCache = {
+-        configString: (0, _fastJsonStableStringify().default)(this._config),
++        configString,
+         ignorePatternsRegExp: calcIgnorePatternRegExp(this._config),
+         transformRegExp: calcTransformRegExp(this._config),
+         transformedFiles: new Map()
+       };
+-      projectCaches.set(config, projectCache);
++      projectCaches.set(configString, projectCache);
+     }
+
+     this._cache = projectCache;