chore: simplify jest config test helper + moves test utils

- removes complex jest-config test helpers and simplify the tool
- removes unused (anymore) rootDir() related code
- improves readability of html-transform test
- moves `test-utils.ts` into `__helpers__` dir

scripts/tests.js

@@ -13,11 +13,19 @@ function getDirectories(rootDir) {
   });
 }
 
+function isJestFolder(basename) {
+  return basename.startsWith('__') && basename.endsWith('__');
+}
+
+// TODO: later we could add a `.test-case-keep` empty file in each folder?
+// ...or move all into a `test-cases` dedicated directory
+function isTestCaseFolder(basename) {
+  return !isJestFolder(basename);
+}
+
 function createIntegrationMock() {
   const testsRoot = 'tests';
-  const testCaseFolders = getDirectories(testsRoot).filter(function(testDir) {
-    return !/^(?:utils|__.+__)$/.test(testDir);
-  });
+  const testCaseFolders = getDirectories(testsRoot).filter(isTestCaseFolder);
 
   testCaseFolders.forEach(directory => {
     const testCaseNodeModules = path.join(testsRoot, directory, 'node_modules');
@@ -41,9 +49,6 @@ function createIntegrationMock() {
 
 createIntegrationMock();
 
-// HACK: allow us to change the `startDir()` during tests
-process.env.__RUNNING_TS_JEST_TESTS = Date.now();
-
 const argv = process.argv.slice(2);
 argv.push('--no-cache');
 argv.push('--testPathPattern', '^(?!(.*watch.spec.ts$)).*');

src/preprocess.ts

@@ -22,7 +22,11 @@ export default function preprocess(
   const isHtmlFile = /\.html$/.test(filePath);
 
   // This is to support angular 2. See https://github.com/kulshekhar/ts-jest/pull/145
-  if (isHtmlFile && (jestConfig.globals as any).__TRANSFORM_HTML__) {
+  if (
+    isHtmlFile &&
+    jestConfig.globals &&
+    (jestConfig.globals as any).__TRANSFORM_HTML__
+  ) {
     src = 'module.exports=' + JSON.stringify(src) + ';';
   }
 

src/utils/get-ts-config.ts

@@ -95,19 +95,6 @@ function readCompilerOptions(configPath: string): CompilerOptions {
   return options;
 }
 
-// function getStartDir(jestConfig: jest.ProjectConfig): string {
-//   // This is needed because of the way our tests are structured.
-//   // If this is being executed as a library (under node_modules)
-//   // we want to start with the project directory that's three
-//   // levels above.
-//   // If this is being executed from the test suite, we want to start
-//   // in the directory of the test
-
-//   // TODO: shouldn't we use the path of jest config here instead of '.' ?
-//   // return process.env.__RUNNING_TS_JEST_TESTS ? process.cwd() : '.';
-//   return process.env.__RUNNING_TS_JEST_TESTS ? process.cwd() : (jestConfig.rootDir || process.cwd());
-// }
-
 // we don't need any data, just its full path
 const tsConfigReader = { basename: TSCONFIG_FILENAME, read: () => 0 };
 

tests/__helpers__/mock-jest-config.ts

@@ -0,0 +1,26 @@
+import { TsJestConfig } from '../../dist/types';
+
+const { resolve } = require.requireActual('path');
+
+/**
+ * Mock a jest config object for the test case in given folder
+ *
+ * Basically it defines `rootDir` and `cwd` properties to the full path of that
+ * test case, as Jest would do.
+ *
+ * Accepts an optional config object, which will be defined on `globals.ts-jest`
+ */
+export default function mockJestConfig(
+  testCaseFolder: string,
+  tsJest: TsJestConfig | null = null,
+): jest.ProjectConfig {
+  // resolves the path since jest would give a resolved path
+  const rootDir = resolve(__dirname, '..', testCaseFolder);
+  // create base jest config object
+  let options: any = { rootDir, cwd: rootDir };
+  // adds TS Jest options if any given
+  if (tsJest != null) {
+    options.globals = { 'ts-jest': tsJest };
+  }
+  return options;
+}

tests/__tests__/get-cache-key.spec.ts

@@ -1,5 +1,5 @@
 import getCacheKey from '../../dist/utils/get-cache-key';
-import cfg from '../__helpers__/jest-config';
+import mockJestConfig from '../__helpers__/mock-jest-config';
 import _getTSConfig from '../../dist/utils/get-ts-config';
 
 jest.mock('../../dist/utils/get-ts-config', () => {
@@ -13,10 +13,11 @@ const getTSConfig: jest.Mock = _getTSConfig as any;
 
 describe('getCacheKey', () => {
   const src = 'console.log(123);';
-  const jestConfig = cfg.simple(null, {
+  const jestConfig = {
+    ...mockJestConfig('simple'),
     transform: { '^.+\\\\.tsx?$': '../../preprocessor.js' },
     testRegex: '(/__tests__/.*|(\\\\.|/)(test|spec))\\\\.(jsx?|tsx?)$',
-  });
+  };
   const filepath = `${jestConfig.rootDir}/some-file.ts`;
   const configStr = JSON.stringify(jestConfig);
   const options = { instrument: false, rootDir: jestConfig.rootDir };

tests/__tests__/html-transform.spec.ts

@@ -1,32 +1,47 @@
 import * as tsJest from '../../dist';
-import jestConfig from '../__helpers__/jest-config';
+import mockJestConfig from '../__helpers__/mock-jest-config';
 
-const config = jestConfig.simple({});
-const filePath = `${config.rootDir}/some-file.html`;
+const TEST_CASE = 'simple';
+const FILENAME = 'some-file.html';
 
-// wrap a transformed source so that we can fake a `require()` on it by calling the returned wrapper
-const wrap = (src: string) =>
-  new Function(`var module={}; ${src} return module.exports;`) as any;
-
-const source = `<div class="html-test">
+const fileContent = `<div class="html-test">
   <span class="html-test__element">This is element</span>
   <code>This is a backtilt \`</code>
 </div>`;
 
 describe('Html transforms', () => {
   it('transforms html if config.globals.__TRANSFORM_HTML__ is set', () => {
+    let jestConfig;
+
     // get the untransformed version
-    const untransformed = tsJest.process(source, filePath, { ...config });
-    // ... then the one which should be transformed
-    (config.globals as any).__TRANSFORM_HTML__ = true;
-    const transformed = tsJest.process(source, filePath, config) as string;
-    // ... finally the result of a `require('module-with-transformed-version')`
-    const exported = wrap(transformed)();
+    jestConfig = mockJestConfig(TEST_CASE);
+    const untransformed = tsJest.process(
+      fileContent,
+      `${jestConfig.rootDir}/${FILENAME}`,
+      jestConfig,
+    );
+    expect(untransformed).toBe(fileContent);
+    expect(untransformed).toMatchSnapshot('untransformed');
 
-    expect(exported).toMatchSnapshot('module');
+    // ... then the one which should be transformed
+    jestConfig = {
+      ...mockJestConfig(TEST_CASE),
+      globals: { __TRANSFORM_HTML__: true },
+    };
+    const transformed = tsJest.process(
+      fileContent,
+      `${jestConfig.rootDir}/${FILENAME}`,
+      jestConfig,
+    ) as string;
+    expect(transformed).not.toBe(fileContent);
     expect(transformed).toMatchSnapshot('source');
-    expect(untransformed).toMatchSnapshot('untransformed');
-    // requiring the transformed version should return the same string as the untransformed version
-    expect(exported).toBe(untransformed);
+
+    // ... finally the result of a `require('module-with-transformed-version')`
+    const value = eval(
+      `(function(){const module={}; ${transformed}; return module.exports;})()`,
+    );
+    expect(value).toMatchSnapshot('module');
+    // the value should be the same string as the source version
+    expect(value).toBe(fileContent);
   });
 });