feat: automatically discover executable extensionless scripts

Fixes #90

package.json

@@ -57,6 +57,7 @@
   "dependencies": {
     "babel-polyfill": "^6.13.0",
     "commander": "^2.9.0",
+    "executable": "^4.1.0",
     "fs-promise": "^1.0.0",
     "mz": "^2.4.0",
     "opn": "^4.0.2",

src/config/getFilesToProcess.js

@@ -3,7 +3,7 @@ import { resolve } from 'path';
 
 import getFilesFromPathFile from './getFilesFromPathFile';
 import getFilesUnderPath from '../util/getFilesUnderPath';
-import { coffeePathPredicate, isExtensionless, jsPathFor } from '../util/FilePaths';
+import { shouldConvertFile, isExtensionless, jsPathFor } from '../util/FilePaths';
 import CLIError from '../util/CLIError';
 
 export default async function getFilesToProcess(config) {
@@ -22,9 +22,9 @@ async function resolveFilesToProcess(config) {
     return await getFilesFromPathFile(pathFile);
   }
   if (searchDirectory) {
-    return await getFilesUnderPath(searchDirectory, coffeePathPredicate);
+    return await getFilesUnderPath(searchDirectory, shouldConvertFile);
   }
-  return await getFilesUnderPath('.', coffeePathPredicate);
+  return await getFilesUnderPath('.', shouldConvertFile);
 }
 
 function resolveFileFilter(filesToProcess, config) {

src/util/FilePaths.js

@@ -1,3 +1,5 @@
+import executable from 'executable';
+import { readFile } from 'mz/fs';
 import { basename, dirname, extname, join } from 'path';
 
 const COFFEE_EXTENSIONS = ['.coffee', '.litcoffee', '.coffee.md'];
@@ -14,9 +16,19 @@ function basePathFor(path) {
   return join(dirname(path), basename(path, extension));
 }
 
-export function coffeePathPredicate(path) {
-  return COFFEE_EXTENSIONS.some(ext =>
-    path.endsWith(ext) && !path.endsWith(`.original${ext}`));
+export async function shouldConvertFile(path) {
+  if (COFFEE_EXTENSIONS.some(ext =>
+      path.endsWith(ext) && !path.endsWith(`.original${ext}`))) {
+    return true;
+  }
+  if (isExtensionless(path) && await executable(path)) {
+    let contents = await readFile(path);
+    let firstLine = contents.toString().split('\n')[0];
+    if (firstLine.startsWith('#!') && firstLine.includes('coffee')) {
+      return true;
+    }
+  }
+  return false;
 }
 
 export function isExtensionless(path) {

src/util/getFilesUnderPath.js

@@ -5,7 +5,7 @@ import { join } from 'path';
  * Recursively discover any matching files in the current directory, ignoring
  * things like node_modules and .git.
  */
-export default async function getFilesUnderPath(dirPath, pathPredicate) {
+export default async function getFilesUnderPath(dirPath, asyncPathPredicate) {
   let resultFiles = [];
   let children = await readdir(dirPath);
   for (let child of children) {
@@ -14,9 +14,9 @@ export default async function getFilesUnderPath(dirPath, pathPredicate) {
     }
     let childPath = join(dirPath, child);
     if ((await stat(childPath)).isDirectory()) {
-      let subdirCoffeeFiles = await getFilesUnderPath(childPath, pathPredicate);
+      let subdirCoffeeFiles = await getFilesUnderPath(childPath, asyncPathPredicate);
       resultFiles.push(...subdirCoffeeFiles);
-    } else if (pathPredicate(child)) {
+    } else if (await asyncPathPredicate(child)) {
       resultFiles.push(childPath);
     }
   }

test/bulk-decaffeinate-test.js

@@ -104,4 +104,13 @@ describe('check', () => {
       assertIncludes(stdout, 'All checks succeeded');
     });
   });
+
+  it('automatically discovers executable scripts', async function() {
+    await runWithTemplateDir('executable-extensionless-scripts', async function() {
+      let {stdout, stderr} = await runCli('check');
+      assert.equal(stderr, '');
+      assertIncludes(stdout, 'Doing a dry run of decaffeinate on 1 file...');
+      assertIncludes(stdout, 'All checks succeeded');
+    });
+  });
 });

test/convert-test.js

@@ -1,7 +1,7 @@
 /* eslint-env mocha */
 import assert from 'assert';
 import { exec } from 'mz/child_process';
-import { exists, writeFile } from 'mz/fs';
+import { exists, readFile, writeFile } from 'mz/fs';
 
 import {
   assertFileContents,
@@ -222,6 +222,28 @@ console.log('Ran the thing!');
     });
   });
 
+  it('automatically discovers and converts extensionless scripts', async function() {
+    await runWithTemplateDir('executable-extensionless-scripts', async function () {
+      let untouchedContents1 = (await readFile('./executableScriptWithoutShebang')).toString();
+      let untouchedContents2 = (await readFile('./executableScriptWithWrongShebang')).toString();
+      let untouchedContents3 = (await readFile('./nonExecutableScript')).toString();
+
+      await initGitRepo();
+      await runCliExpectSuccess('convert');
+
+      await assertFileContents('./executableScript', `\
+#!/usr/bin/env node
+// TODO: This file was created by bulk-decaffeinate.
+// Sanity-check the conversion and remove this comment.
+
+console.log('This script is executable so it should be converted.');
+`);
+      await assertFileContents('./executableScriptWithoutShebang', untouchedContents1);
+      await assertFileContents('./executableScriptWithWrongShebang', untouchedContents2);
+      await assertFileContents('./nonExecutableScript', untouchedContents3);
+    });
+  });
+
   it('allows converting a directory with no files', async function() {
     await runWithTemplateDir('empty-directory', async function () {
       await initGitRepo();

test/examples/executable-extensionless-scripts/executableScript

@@ -0,0 +1,3 @@
+#!/usr/bin/env coffee
+
+console.log 'This script is executable so it should be converted.'

test/examples/executable-extensionless-scripts/executableScriptWithWrongShebang

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo 'This is not a CoffeeScript file, so should not be converted.'

test/examples/executable-extensionless-scripts/executableScriptWithoutShebang

@@ -0,0 +1 @@
+console.log 'This script has no shebang line, so should not be converted.'

test/examples/executable-extensionless-scripts/nonExecutableScript

@@ -0,0 +1,3 @@
+#!/usr/bin/env coffee
+
+console.log 'This script is not executable so it should not be converted.'