Compile Plugins written in Typescript

README.md

@@ -52,14 +52,17 @@ $ codemod --find-babel-config --plugin ./my-plugin.js src/
 This requires that all babel plugins and presets be installed locally and are listed in your `.babelrc` file. `babel-codemod` uses `babel-register` under the hood too accomplish this and all `.babelrc` [lookup rules apply](https://babeljs.io/docs/usage/babelrc/#lookup-behavior).
 
 ### Transpiling using TypeScript
+`babel-codemod` supports plugins written in TypeScript.  
 
-There is currently an [open issue](https://github.com/square/babel-codemod/issues/51) for supporting plugins written in typescript. In the interim, you can take the same approach using `--require` along with `ts-node/register`.
+Unlike babel transpilation described above, this feature is off by default and **requires that TypeScript be installed locally**.  This feature uses `ts-node/register` under the hood so [all rules](https://www.typescriptlang.org/docs/handbook/tsconfig-json.html) regarding existence and placement of `tsconfig.json` apply.
+
+To opt-in to TypeScript transpilation of your plugins, simply pass the `--transpile-ts-plugins` option.
 
 For example:
 
 ```sh
 # Run a local plugin written with TypeScript.
-$ codemod --require ts-node/register --plugin ./my-plugin.ts src/
+$ codemod --transpile-ts-plugins --plugin ./my-plugin.ts src/
 ```
 
 ## Contributing

package.json

@@ -73,7 +73,8 @@
     "recast": "^0.13.0",
     "resolve": "^1.5.0",
     "tmp": "^0.0.33",
-    "whatwg-url": "^6.4.0"
+    "whatwg-url": "^6.4.0",
+    "ts-node": "^4.1.0"
   },
   "engines": {
     "node": ">=6.0.0"

src/Options.ts

@@ -41,16 +41,26 @@ export default class Options {
     readonly requires: Array<string>,
     readonly transpilePlugins: boolean,
     readonly findBabelConfig: boolean,
+    readonly transpilePluginsWithTypescript: boolean,
     readonly ignore: PathPredicate,
     readonly stdio: boolean,
     readonly help: boolean,
     readonly dry: boolean
-  ) {}
+  ) {
+    const defaultFileSystemExtensions = new Set(['.js']);
+    if (transpilePluginsWithTypescript) {
+      {
+        defaultFileSystemExtensions.add('.ts');
+      }
+    }
 
-  private pluginLoader = new PluginLoader([
-    new FileSystemResolver(),
-    new PackageResolver()
-  ]);
+    this.pluginLoader = new PluginLoader([
+      new FileSystemResolver(defaultFileSystemExtensions),
+      new PackageResolver()
+    ]);
+  }
+
+  private pluginLoader: PluginLoader;
 
   private remotePluginLoader = new PluginLoader([
     new AstExplorerResolver(),
@@ -109,6 +119,18 @@ export default class Options {
     }
   }
 
+  loadTypescriptTranspile() {
+    try {
+      require.resolve('typescript');
+    } catch (e) {
+      throw new Error(
+        'Typescript is not installed locally. You must installed Typescript locally in order to transpile plugins written in Typescript'
+      );
+    }
+
+    require('ts-node').register();
+  }
+
   async getPlugin(name: string): Promise<Plugin | null> {
     for (let plugin of await this.getPlugins()) {
       if (plugin.declaredName === name || plugin.inferredName === name) {
@@ -164,6 +186,7 @@ export default class Options {
     let requires: Array<string> = [];
     let findBabelConfig = false;
     let transpilePlugins = true;
+    let transpilePluginsWithTypescript = false;
     let stdio = false;
     let help = false;
     let dry = false;
@@ -222,6 +245,10 @@ export default class Options {
           findBabelConfig = arg === '--find-babel-config';
           break;
 
+        case '--transpile-ts-plugins':
+          transpilePluginsWithTypescript = true;
+          break;
+
         case '--extensions':
           i++;
           extensions = new Set(
@@ -267,6 +294,7 @@ export default class Options {
       requires,
       transpilePlugins,
       findBabelConfig,
+      transpilePluginsWithTypescript,
       ignore,
       stdio,
       help,

src/index.ts

@@ -22,6 +22,7 @@ OPTIONS
       --[no-]transpile-plugins      Transpile plugins to enable future syntax (default: on).
       --[no-]find-babel-config      Run plugins through babel plugins/presets specified in local
                                     .babelrc file instead of babel-preset-env (default: off).
+      --transpile-ts-plugins        Transpile plugins to enable typescript syntax. Requires typescript to be installed local to project. (default: off).
   -s, --stdio                       Read source from stdin and print to stdout.
   -h, --help                        Show this help message.
   -d, --dry                         Run plugins without modifying files on disk.
@@ -79,8 +80,14 @@ export default async function run(
     return 0;
   }
 
+  if(options.transpilePluginsWithTypescript){
+    options.loadTypescriptTranspile();
+  }
+
+
   options.loadBabelTranspile();
 
+
   options.loadRequires();
 
   let plugins = await options.getBabelPlugins();

test/cli/CLITest.ts

@@ -229,4 +229,87 @@ describe('CLI', function() {
       await server.stop();
     }
   });
+
+  it('can load plugins written in Typescript', async function() {
+    let afile = await createTemporaryFile('a-file.js', '3 + 4;');
+    let { status, stdout, stderr } = await runCodemodCLI([
+      afile,
+      '-p',
+      plugin('typescript/increment-typescript', '.ts'),
+      '--transpile-ts-plugins'
+    ]);
+
+    deepEqual(
+      { status, stdout, stderr },
+      {
+        status: 0,
+        stdout: `${afile}\n1 file(s), 1 modified, 0 errors\n`,
+        stderr: ''
+      }
+    );
+    strictEqual(await readFile(afile, 'utf8'), '4 + 5;');
+  });
+
+  it('can load plugins written in Typescript without ts extension', async function() {
+    let afile = await createTemporaryFile('a-file.js', '3 + 4;');
+    let { status, stdout, stderr } = await runCodemodCLI([
+      afile,
+      '-p',
+      plugin('typescript/increment-typescript', ''),
+      '--transpile-ts-plugins'
+    ]);
+
+    deepEqual(
+      { status, stdout, stderr },
+      {
+        status: 0,
+        stdout: `${afile}\n1 file(s), 1 modified, 0 errors\n`,
+        stderr: ''
+      }
+    );
+    strictEqual(await readFile(afile, 'utf8'), '4 + 5;');
+  });
+
+  it('can load plugins with multiple files written in Typescript', async function() {
+    let afile = await createTemporaryFile('a-file.js', '3 + 4;');
+    let { status, stdout, stderr } = await runCodemodCLI([
+      afile,
+      '-p',
+      plugin('typescript/increment-export-default-multiple/index', '.ts'),
+      '--transpile-ts-plugins'
+    ]);
+
+    deepEqual(
+      { status, stdout, stderr },
+      {
+        status: 0,
+        stdout: `${afile}\n1 file(s), 1 modified, 0 errors\n`,
+        stderr: ''
+      }
+    );
+    strictEqual(await readFile(afile, 'utf8'), '4 + 5;');
+  });
+
+  it('can load plugins with multiple files written in Typescript and Javascript', async function() {
+    let afile = await createTemporaryFile('a-file.js', '3 + 4;');
+    let { status, stdout, stderr } = await runCodemodCLI([
+      afile,
+      '-p',
+      plugin(
+        'typescript/increment-export-default-multiple/increment-export-index',
+        '.ts'
+      ),
+      '--transpile-ts-plugins'
+    ]);
+
+    deepEqual(
+      { status, stdout, stderr },
+      {
+        status: 0,
+        stdout: `${afile}\n1 file(s), 1 modified, 0 errors\n`,
+        stderr: ''
+      }
+    );
+    strictEqual(await readFile(afile, 'utf8'), '4 + 5;');
+  });
 });

test/fixtures/plugin/typescript/increment-export-default-multiple/increment-export-default-js.js

@@ -0,0 +1,3 @@
+export function incrementValue(x) {
+  return x + 1;
+}

test/fixtures/plugin/typescript/increment-export-default-multiple/increment-export-default.ts

@@ -0,0 +1,3 @@
+export function incrementValue(x: number): number {
+  return x + 1;
+}

test/fixtures/plugin/typescript/increment-export-default-multiple/increment-export-index.ts

@@ -0,0 +1,13 @@
+import { incrementValue } from './increment-export-default-js';
+
+/* tslint:disable */
+export default function() {
+  return {
+    visitor: {
+      NumericLiteral(path) {
+        let value: number = path.node.value;
+        path.node.value = incrementValue(value);
+      }
+    }
+  };
+}

test/fixtures/plugin/typescript/increment-export-default-multiple/index.ts

@@ -0,0 +1,13 @@
+import {incrementValue} from './increment-export-default';
+
+/* tslint:disable */
+export default function() {
+  return {
+    visitor: {
+      NumericLiteral(path) {
+        let value: number = path.node.value;
+        path.node.value = incrementValue(value);
+      }
+    }
+  };
+}

test/fixtures/plugin/typescript/increment-typescript.ts

@@ -0,0 +1,15 @@
+function incrementValue(x: number): number {
+  return x + 1;
+}
+
+/* tslint:disable */
+export default function() {
+  return {
+    visitor: {
+      NumericLiteral(path) {
+        let value: number = path.node.value;
+        path.node.value = incrementValue(value);
+      }
+    }
+  };
+}

test/helpers/plugin.ts

@@ -1,5 +1,5 @@
 import { join } from 'path';
 
-export default function plugin(name: string): string {
-  return join(__dirname, `../fixtures/plugin/${name}.js`);
+export default function plugin(name: string, ext: string = '.js'): string {
+  return join(__dirname, `../fixtures/plugin/${name}${ext}`);
 }

tsconfig.json

@@ -1,10 +1,13 @@
 {
-  "compilerOptions": {
-    "module": "commonjs",
-    "target": "es6",
-    "noImplicitAny": false,
-    "sourceMap": true,
-    "strictNullChecks": true,
-    "declaration": true
-  }
-}
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es6",
+        "noImplicitAny": false,
+        "sourceMap": true,
+        "strictNullChecks": true,
+        "declaration": true
+    },
+    "exclude": [
+        "./test/fixtures/**/*.ts"
+    ]
+}