Initial commit

.gitignore

@@ -59,3 +59,9 @@ typings/
 
 # next.js build output
 .next
+
+
+# IntelliJ
+
+.idea/*
+*.iml

package.json

@@ -0,0 +1,15 @@
+{
+  "name": "sample-js-codemod",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "jest"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "jscodeshift": "^0.6.3",
+    "jest": "^24.1.0"
+  }
+}

src/__testfixtures__/defaultExportedArrow.input.js

@@ -0,0 +1 @@
+export default (a, b) => a + b;

src/__testfixtures__/defaultExportedArrow.output.js

@@ -0,0 +1,3 @@
+export default function (a, b) {
+  return a + b;
+}

src/__tests__/arrow-to-function.test.js

@@ -0,0 +1,6 @@
+jest.autoMockOff();
+const defineTest = require('../../src/testUtils').defineTest;
+
+describe('arrow-to-function', () => {
+    defineTest(__dirname, 'arrow-to-function', null, 'defaultExportedArrow');
+});

src/arrow-to-function.js

@@ -0,0 +1,15 @@
+module.exports = function transform(file, api) {
+  const j = api.jscodeshift;
+
+  return j(file.source)
+    .find(j.ArrowFunctionExpression)
+    .replaceWith(
+      p => {
+        const nodeValue = p.value;
+        return j.functionDeclaration(j.identifier(''), nodeValue.params,
+            j.blockStatement([j.returnStatement(nodeValue.body)])
+            );
+      }
+    )
+    .toSource();
+};

src/testUtils.js

@@ -0,0 +1,103 @@
+/**
+ *  Copyright (c) 2016-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+/* global expect, describe, it */
+
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+function runInlineTest(module, options, input, expectedOutput) {
+    // Handle ES6 modules using default export for the transform
+    const transform = module.default ? module.default : module;
+
+    // Jest resets the module registry after each test, so we need to always get
+    // a fresh copy of jscodeshift on every test run.
+    let jscodeshift = require('jscodeshift');
+    if (module.parser) {
+        jscodeshift = jscodeshift.withParser(module.parser);
+    }
+
+    const output = transform(
+        input,
+        {
+            jscodeshift,
+            stats: () => {},
+        },
+        options || {}
+    );
+    expect((output || '').trim()).toEqual(expectedOutput.trim());
+}
+exports.runInlineTest = runInlineTest;
+
+/**
+ * Utility function to run a jscodeshift script within a unit test. This makes
+ * several assumptions about the environment:
+ *
+ * - `dirName` contains the name of the directory the test is located in. This
+ *   should normally be passed via __dirname.
+ * - The test should be located in a subdirectory next to the transform itself.
+ *   Commonly tests are located in a directory called __tests__.
+ * - `transformName` contains the filename of the transform being tested,
+ *   excluding the .js extension.
+ * - `testFilePrefix` optionally contains the name of the file with the test
+ *   data. If not specified, it defaults to the same value as `transformName`.
+ *   This will be suffixed with ".input.js" for the input file and ".output.js"
+ *   for the expected output. For example, if set to "foo", we will read the
+ *   "foo.input.js" file, pass this to the transform, and expect its output to
+ *   be equal to the contents of "foo.output.js".
+ * - Test data should be located in a directory called __testfixtures__
+ *   alongside the transform and __tests__ directory.
+ */
+function runTest(dirName, transformName, options, testFilePrefix) {
+    if (!testFilePrefix) {
+        testFilePrefix = transformName;
+    }
+
+    const fixtureDir = path.join(dirName, '..', '__testfixtures__');
+    const inputPath = path.join(fixtureDir, testFilePrefix + '.input.js');
+    const source = fs.readFileSync(inputPath, 'utf8');
+    const expectedOutput = fs.readFileSync(
+        path.join(fixtureDir, testFilePrefix + '.output.js'),
+        'utf8'
+    );
+    // Assumes transform is one level up from __tests__ directory
+    const module = require(path.join(dirName, '..', transformName + '.js'));
+    runInlineTest(module, options, {
+        path: inputPath,
+        source
+    }, expectedOutput);
+}
+exports.runTest = runTest;
+
+/**
+ * Handles some boilerplate around defining a simple jest/Jasmine test for a
+ * jscodeshift transform.
+ */
+function defineTest(dirName, transformName, options, testFilePrefix) {
+    const testName = testFilePrefix
+        ? `transforms correctly using "${testFilePrefix}" data`
+        : 'transforms correctly';
+    describe(transformName, () => {
+        it(testName, () => {
+            runTest(dirName, transformName, options, testFilePrefix);
+        });
+    });
+}
+exports.defineTest = defineTest;
+
+function defineInlineTest(module, options, input, expectedOutput, testName) {
+    it(testName || 'transforms correctly', () => {
+        runInlineTest(module, options, {
+            source: input
+        }, expectedOutput);
+    });
+}
+exports.defineInlineTest = defineInlineTest;