migrate comparison tests to Jest snapshot tests

.github/workflows/push.yml

@@ -16,8 +16,8 @@ jobs:
       - name: build
         run: yarn build
 
-      - name: install typescript
-        run: yarn add typescript@3.9.3
+      - name: snapshot test
+        run: yarn jest --color --testTimeout=8000
 
       - name: test
         run: sudo yarn comparison-tests
@@ -43,8 +43,8 @@ jobs:
         run: yarn build
         working-directory: C:\source\ts-loader
 
-      - name: install typescript
-        run: yarn add typescript@3.9.3
+      - name: snapshot test
+        run: yarn jest --color --testTimeout=8000 --testPathIgnorePatterns=issue441 --maxWorkers=1
         working-directory: C:\source\ts-loader
 
       - name: test

jest.config.json

@@ -0,0 +1,14 @@
+{
+  "preset": "ts-jest",
+  "testRunner": "jest-circus/runner",
+  "testEnvironment": "node",
+  "modulePathIgnorePatterns": [
+    "<rootDir>/examples/.*",
+    "<rootDir>/test/execution-tests/.*"
+  ],
+  "globals": {
+    "ts-jest": {
+      "isolatedModules": true
+    }
+  }
+}

package.json

@@ -61,6 +61,8 @@
     "semver": "^6.0.0"
   },
   "devDependencies": {
+    "@types/fs-extra": "^9.0.1",
+    "@types/jest": "^26.0.4",
     "@types/micromatch": "^3.1.0",
     "@types/node": "*",
     "@types/semver": "^6.0.0",
@@ -84,6 +86,8 @@
     "html-webpack-plugin": "^3.2.0",
     "husky": "^2.0.0",
     "jasmine-core": "^3.0.0",
+    "jest": "^26.1.0",
+    "jest-circus": "^26.1.0",
     "karma": "^4.0.0",
     "karma-chrome-launcher": "^2.2.0",
     "karma-jasmine": "^2.0.0",
@@ -92,10 +96,13 @@
     "karma-webpack": "^4.0.0-rc.5",
     "lint-staged": "^8.0.0",
     "markdown-toc": "^1.2.0",
+    "memfs": "^3.2.0",
     "mkdirp": "^0.5.1",
     "mocha": "^6.0.0",
     "prettier": "^2.0.5",
     "rimraf": "^2.6.2",
+    "rxjs": "^6.6.0",
+    "ts-jest": "^26.1.3",
     "typescript": "^3.6.2",
     "webpack": "^4.5.0",
     "webpack-cli": "^3.1.1"

src/tsconfig.json

@@ -4,6 +4,7 @@
     "noImplicitReturns": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
+    "skipLibCheck": true,
     "suppressImplicitAnyIndexErrors": true,
     "strict": true,
     "module": "commonjs",