Jest support (#351)

* Adds WIP core and tests for jest support * Adds functional way to generalize all test cases and file names * Fixes eslint errors and adds support for 'transform' config objects * Adds support for option values types 'string' and 'array' * Adds support for removing 'node_modules' from [moduleName, options] type * Reworks 'testJest()' to ignore array order of dependencies * Adds more tests for modules with options or referenced files * Removes unnecessary conditionals for technically invalid jest configs * Adds test to get code coverage to 100% * Adds entry for jest to 'Special' section in README * Fixes linting error in test/special/jest * 0.9.0 * Revert "0.9.0" This reverts commit 849a844.
depcheck · May 25, 2019 · 13bd6e8 · 13bd6e8
1 parent eb69af9
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diff --git a/README.md b/README.md
@@ -48,6 +48,7 @@ The *special* component is used to recognize the dependencies that are not gener
 - [Grunt](https://www.npmjs.com/package/grunt) plugins
 - `feross-standard` - [Feross standard](https://www.npmjs.com/package/standard) format parser
 - `mocha` - [Mocha](https://www.npmjs.com/package/mocha) explicit required dependencies
+- `jest` - [Jest](https://www.npmjs.com/package/jest) properties in [Jest Configuration](https://jestjs.io/docs/en/configuration)
 - `commitizen` - [Commitizen](https://www.npmjs.com/package/commitizen) configuration adaptor
 - `gulp-load-plugins` - [Gulp-load-plugins](https://www.npmjs.com/package/gulp-load-plugins) lazy loaded plugins
 - `gatsby` - [Gatsby](https://www.npmjs.com/package/gatsby) configuration parser

diff --git a/src/special/jest.js b/src/special/jest.js
@@ -0,0 +1,116 @@
+import path from 'path';
+import lodash from 'lodash';
+
+const _ = lodash;
+
+const jestConfigRegex = /jest.conf(ig|).js(on|)$/;
+const supportedProperties = [
+  'dependencyExtractor',
+  'preset',
+  'prettierPath',
+  'reporters',
+  'runner',
+  'setupFiles',
+  'setupFilesAfterEnv',
+  'snapshotResolver',
+  'snapshotSerializers',
+  'testEnvironment',
+  'testResultsProcessor',
+  'testRunner',
+  'transform',
+  'watchPlugins',
+];
+
+function parse(content) {
+  try {
+    return JSON.parse(content);
+  } catch (error) {
+    return {}; // ignore parse error silently
+  }
+}
+
+function contain(array, dep, prefix) {
+  if (!array) {
+    return false;
+  }
+
+  if (typeof array === 'string') {
+    return contain([array], dep, prefix);
+  }
+
+  // extract name if wrapping with options
+  const names = array.map(item => (lodash.isString(item) ? item : item[0]));
+  if (names.indexOf(dep) !== -1) {
+    return true;
+  }
+
+  if (prefix && dep.indexOf(prefix) === 0) {
+    return contain(array, dep.substring(prefix.length), false);
+  }
+
+  return false;
+}
+
+function removeNodeModuleRelativePaths(filepath) {
+  if (Array.isArray(filepath)) {
+    return removeNodeModuleRelativePaths(filepath[0]);
+  }
+  return filepath.replace(/^.*node_modules\//, '').replace(/\/.*/, '');
+}
+
+function filter(deps, options) {
+  const runner = deps.filter(dep => (
+    contain(options.runner, dep, 'jest-runner-')
+  ));
+
+  const watchPlugins = deps.filter(dep => (
+    contain(options.watchPlugins, dep, 'jest-watch-')
+  ));
+
+  const otherProps = lodash(options)
+    .entries()
+    .map(([prop, value]) => {
+      if (prop === 'transform') {
+        return _.values(value).map(removeNodeModuleRelativePaths);
+      }
+      if (Array.isArray(value)) {
+        return value.map(removeNodeModuleRelativePaths);
+      }
+      return removeNodeModuleRelativePaths(value);
+    })
+    .flatten()
+    .intersection(deps)
+    .value();
+
+  return _.uniq(runner.concat(watchPlugins).concat(otherProps));
+}
+
+function checkOptions(deps, options = {}) {
+  const pickedOptions = lodash(options)
+    .pick(supportedProperties)
+    .value();
+  return filter(deps, pickedOptions);
+}
+
+export default function parseJest(content, filePath, deps, rootDir) {
+  const filename = path.basename(filePath);
+  if (jestConfigRegex.test(filename)) {
+    try {
+      // eslint-disable-next-line global-require
+      const options = require(filePath) || {};
+      return checkOptions(deps, options);
+    } catch (error) {
+      return [];
+    }
+  }
+
+  const packageJsonPath = path.resolve(rootDir, 'package.json');
+  const resolvedFilePath = path.resolve(rootDir, filename);
+
+  if (resolvedFilePath === packageJsonPath) {
+    const metadata = parse(content);
+    return checkOptions(deps, metadata.jest);
+  }
+
+  return [];
+}
diff --git a/test/special/jest.js b/test/special/jest.js
@@ -0,0 +1,243 @@
+/* global describe, it */
+
+import 'should';
+import path from 'path';
+import fse from 'fs-extra';
+import jestSpecialParser from '../../src/special/jest';
+
+const configFileNames = [
+  'jest.config.js',
+  'jest.conf.js',
+  'jest.config.json',
+  'jest.conf.json',
+];
+
+const testCases = [
+  {
+    name: 'ignore when the config is the empty object',
+    deps: [],
+    content: {},
+  },
+  {
+    name: 'recognize single short-name jest-runner',
+    deps: ['jest-runner-mocha'],
+    content: { runner: 'mocha' },
+  },
+  {
+    name: 'recognize single long-name jest-runner',
+    deps: ['jest-runner-mocha'],
+    content: { runner: 'jest-runner-mocha' },
+  },
+  {
+    name: 'recognize single short-name jest-watch plugin',
+    deps: ['jest-watch-master'],
+    content: { watchPlugins: ['master'] },
+  },
+  {
+    name: 'recognize single long-name jest-watch plugin',
+    deps: ['jest-watch-master'],
+    content: { watchPlugins: ['jest-watch-master'] },
+  },
+  {
+    name: 'recognize multiple short-name jest-watch plugin',
+    deps: ['jest-watch-master', 'jest-watch-select-projects'],
+    content: { watchPlugins: ['master', 'select-projects'] },
+  },
+  {
+    name: 'recognize module with options',
+    deps: ['jest-watch-master'],
+    content: {
+      watchPlugins: [
+        [
+          'master',
+          {
+            key: 'k',
+            prompt: 'show a custom prompt',
+          },
+        ],
+      ],
+    },
+  },
+  {
+    name: 'recognize transform path with node_modules',
+    deps: ['babel-jest'],
+    content: {
+      transform: {
+        '^.+\\.js$': '<rootDir>/node_modules/babel-jest',
+      },
+    },
+  },
+  {
+    name: 'recognize duplicated transformer',
+    deps: ['babel-jest'],
+    content: {
+      transform: {
+        '^.+\\.js?$': 'babel-jest',
+        '^.+\\.jsx?$': 'babel-jest',
+      },
+    },
+  },
+  {
+    name: 'recognize module when preset is referenced',
+    deps: ['foo-bar'],
+    content: {
+      preset: './node_modules/foo-bar/jest-preset.js',
+    },
+  },
+  {
+    name: 'recognize reporter when defined with options',
+    deps: ['jest-custom-reporter', 'jest-reporter'],
+    content: {
+      reporters: [
+        [
+          'jest-custom-reporter',
+          { foo: 'bar' },
+        ],
+        [
+          '<rootDir>/node_modules/jest-reporter',
+          { jest: 'reporter' },
+        ],
+      ],
+    },
+  },
+  {
+    name: 'recognize array of strings of modules',
+    deps: ['foo', 'bar', 'jest', 'babel-jest'],
+    content: {
+      setupFiles: [
+        '<rootDir>/node_modules/foo',
+        '../node_modules/bar',
+        'jest',
+        './node_modules/babel-jest/custom-setup.js',
+      ],
+    },
+  },
+  {
+    name: 'recognize multiple options',
+    deps: ['babel-jest', 'vue-jest', 'jest-serializer-vue'],
+    content: {
+      transform: {
+        '^.+\\.js$': '<rootDir>/node_modules/babel-jest',
+        '^.+\\.vue$': 'vue-jest',
+      },
+      snapshotSerializers: ['jest-serializer-vue'],
+    },
+  },
+];
+
+function random() {
+  return Math.random().toString().substring(2);
+}
+
+async function getTempPath(filename, content) {
+  const tempFolder = path.resolve(__dirname, `tmp-${random()}`);
+  const tempPath = path.resolve(tempFolder, filename);
+  await fse.ensureDir(tempFolder);
+  await fse.outputFile(tempPath, content);
+  return tempPath;
+}
+
+async function removeTempFile(filepath) {
+  const fileFolder = path.dirname(filepath);
+  await fse.remove(filepath);
+  await fse.remove(fileFolder);
+}
+
+async function testJest(content, deps, expectedDeps, filename) {
+  const tempPath = await getTempPath(
+    (filename || configFileNames[0]),
+    content,
+  );
+  try {
+    const result = jestSpecialParser(content, tempPath, deps, __dirname);
+    // sort() allows us to ignore order
+    Array.from(result).sort().should.deepEqual(expectedDeps.sort());
+  } finally {
+    await removeTempFile(tempPath);
+  }
+}
+
+describe('jest special parser', () => {
+  it('should ignore when filename is not supported', () => {
+    const result = jestSpecialParser('content', 'jest.js', [], __dirname);
+    result.should.deepEqual([]);
+  });
+
+  it('should handle JSON parse error', () => {
+    const content = '{ this is an invalid JSON string';
+    return testJest(content, [], []);
+  });
+
+  it('should handle parse error for valid JS but invalid JSON', () => {
+    const content = 'module.exports = function() {}';
+    return testJest(content, [], []);
+  });
+
+  it('should ignore unsupported config properties', () => {
+    const content = `module.exports = ${{ unsupported: 'npm-module' }}`;
+    return testJest(content, [], []);
+  });
+
+  it('should recognize unused dependencies in jest config', () => {
+    const config = JSON.stringify(testCases[1].content);
+    const content = `module.exports = ${config}`;
+    const deps = testCases[1].deps.concat(['unused-module']);
+    return testJest(content, deps, testCases[1].deps);
+  });
+
+  it('should handle require call to other modules', () => {
+    const config = JSON.stringify(testCases[1].content);
+    const content = `const fs = require('fs');
+      module.exports = ${config}`;
+    return testJest(content, testCases[1].deps, testCases[1].deps);
+  });
+
+  it('should handle options which are not supported', () => {
+    const result = jestSpecialParser(
+      'module.exports = { automock: true }',
+      'jest.config.js',
+      [],
+      __dirname,
+    );
+    result.should.deepEqual([]);
+  });
+
+  it('should handle JSON parse error when using package.json', () => {
+    const content = '{ this is an invalid JSON string';
+    const result = jestSpecialParser(
+      content,
+      path.resolve(__dirname, 'package.json'),
+      [],
+      __dirname,
+    );
+    result.should.deepEqual([]);
+  });
+
+  it('should handle package.json config', () => {
+    const result = jestSpecialParser(
+      JSON.stringify({ jest: [...testCases].pop().content }),
+      path.resolve(__dirname, 'package.json'),
+      [...testCases].pop().deps,
+      __dirname,
+    );
+    result.sort().should.deepEqual([...testCases].pop().deps.sort());
+  });
+
+  it('should handle if module.exports evaluates to undefined', () => {
+    const content = 'module.exports = undefined';
+    return testJest(content, [], []);
+  });
+
+  configFileNames.forEach(fileName => (
+    testCases.forEach(testCase => (
+      it(`should ${testCase.name} in config file ${fileName}`, () => {
+        const config = JSON.stringify(testCase.content);
+        let content = config;
+        if (fileName.split('.').pop() === 'js') {
+          content = `module.exports = ${config}`;
+        }
+        return testJest(content, testCase.deps, testCase.deps, fileName);
+      })
+    ))
+  ));
+});