Update

Author: simonespa

.gitignore

@@ -1,4 +1,4 @@
 .coverage
-.jest_cache
+.jest
 build
 node_modules

jest.config.ts

@@ -1,17 +1,61 @@
-export default {
-  roots: [
-    '<rootDir>/test'
-  ],
-  testMatch: [
-    '**/?(*.)+(spec|test).+(ts|tsx)'
-  ],
-  transform: {
-    '^.+\\.(ts|tsx)$': 'ts-jest'
-  },
+/**
+ * @see https://jestjs.io/docs/configuration
+ */
+ const config = {
+  // The directory where Jest should store its cached dependency information.
+  cacheDirectory: '.jest',
+
+  /**
+   * Automatically clears all information stored in the mockFn.mock.calls, mockFn.mock.instances and mockFn.mock.results arrays before every test.
+   * Often this is useful when you want to clean up a mocks usage data between two assertions.
+   * Beware that this will replace mockFn.mock, not just these three properties!
+   * You should, therefore, avoid assigning mockFn.mock to other variables, temporary or not, to make sure you don't access stale data.
+   *
+   * @see https://jestjs.io/docs/configuration#clearmocks-boolean
+   * @see https://jestjs.io/docs/jest-object#jestclearallmocks
+   * @see https://jestjs.io/docs/mock-function-api#mockfnmockclear
+   */
+  clearMocks: true,
+
+  // Indicates whether the coverage information should be collected while executing the test
   collectCoverage: true,
+
+  // The directory where Jest should output its coverage files
   coverageDirectory: '.coverage',
-  coverageProvider: 'v8',
-  coveragePathIgnorePatterns: ['/node_modules/'],
+
+  // A list of reporter names that Jest uses when writing coverage reports. Any istanbul reporter can be used.
   coverageReporters: ['text', 'lcov'],
-  cacheDirectory: '.jest_cache'
-}
+
+  /**
+   * This will be used to configure minimum threshold enforcement for coverage results.
+   * Thresholds can be specified as global, as a glob, and as a directory or file path.
+   * If thresholds aren't met, jest will fail.
+   * Thresholds specified as a positive number are taken to be the minimum percentage required.
+   * Thresholds specified as a negative number represent the maximum number of uncovered entities allowed.
+   */
+  coverageThreshold: {
+    global: {
+      branches: 80,
+      functions: 80,
+      lines: 80,
+      statements: -10,
+    },
+  },
+
+  moduleNameMapper: {
+    'src/(.*)': '<rootDir>/src/$1',
+  },
+
+  // A preset that is used as a base for Jest's configuration.
+  preset: 'ts-jest',
+
+  // A list of paths to directories that Jest should use to search for files in.
+  roots: ['<rootDir>/test'],
+
+  // The glob patterns Jest uses to detect test files.
+  testMatch: ['**/?(*.)+(test).+(ts|tsx)'],
+
+  verbose: true,
+};
+
+export default config;

src/index.ts

@@ -1,4 +1,4 @@
-import sum from '../src/sum';
+import sum from 'src/sum';
 
 test('basic', () => {
   const a = 3;

test/sum.test.ts

@@ -1,4 +1,3 @@
-// "outDir": "build",                                   /* Specify an output folder for all emitted files. */
 {
   "compilerOptions": {
     "baseUrl": "./",
@@ -11,7 +10,8 @@
     "skipLibCheck": true,
     "strict": false,
     "forceConsistentCasingInFileNames": true,
-    "noEmit": true,
+    "outDir": "build",
+    "noEmit": false,
     "esModuleInterop": true,
     "module": "esnext",
     "moduleResolution": "node",