fix: add command-exists test to axioms for stability, moved from sync…

… to async calls (todogroup#182)

axioms/licensee.js

@@ -4,16 +4,12 @@
 const licensee = require('../lib/licensee')
 const Result = require('../lib/result')
 
-module.exports = function (fileSystem) {
+module.exports = async function (fileSystem) {
   let licenses = []
   try {
-    licenses = licensee.identifyLicensesSync(fileSystem.targetDir)
+    licenses = await licensee.identifyLicense(fileSystem.targetDir)
   } catch (error) {
-    if (error.message === 'Licensee not installed') {
-      return new Result('Licensee not found in path, only running license-independent rules', [], false)
-    } else {
-      return new Result(error.message, [], false)
-    }
+    return new Result(error.message, [], false)
   }
   return new Result('', licenses.map(l => { return { passed: true, path: l } }), true)
 }

axioms/linguist.js

@@ -4,19 +4,15 @@
 const linguist = require('../lib/linguist')
 const Result = require('../lib/result')
 
-module.exports = function (fileSystem) {
+module.exports = async function (fileSystem) {
   const languages = []
   try {
-    var jsonObj = linguist.identifyLanguagesSync(fileSystem.targetDir)
+    var jsonObj = await linguist.identifyLanguages(fileSystem.targetDir)
     for (var language in jsonObj) {
       languages.push(language.toLowerCase())
     }
   } catch (error) {
-    if (error.message === 'Linguist not installed') {
-      return new Result('Linguist not found in path, only running language-independent rules', [], false)
-    } else {
-      return new Result(error.message, [], false)
-    }
+    return new Result(error.message, [], false)
   }
   return new Result('', languages.map(l => { return { passed: true, path: l } }), true)
 }

lib/command_exists.js

@@ -0,0 +1,31 @@
+// Copyright 2017 TODO Group. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+const commandExistsLib = require('command-exists')
+
+/**
+ * Checks whether or not a list of commands exists in the
+ * current environment. Returns the first command that was
+ * found to exist.
+ *
+ * @protected
+ * @param {string|string[]} command The command or commands to check for.
+ * @returns {string|null} The first command found to exist, or null of none were found.
+ */
+async function commandExists (command) {
+  // convert to array if needed
+  if (!Array.isArray(command)) {
+    command = [command]
+  }
+  for (const commandString of command) {
+    try {
+      await commandExistsLib(commandString)
+      return commandString
+    } catch (e) {
+      // do nothing
+    }
+  }
+  return null
+}
+
+module.exports.commandExists = commandExists

lib/licensee.js

@@ -1,7 +1,7 @@
 // Copyright 2018 TODO Group. All rights reserved.
 // Licensed under the Apache License, Version 2.0.
 
-const isWindows = require('is-windows')
+const { commandExists } = require('./command_exists')
 const spawnSync = require('child_process').spawnSync
 
 class Licensee {
@@ -11,14 +11,17 @@ class Licensee {
    * Throws 'Licensee not installed' error if command line of 'licensee' is not available.
    *
    * @param {string} targetDir The directory to run licensee on
-   * @returns {string[]} License identifiers
+   * @returns {Promise<string[]>} License identifiers
    */
-  identifyLicensesSync (targetDir) {
-    const licenseeOutput = spawnSync(isWindows() ? 'licensee.bat' : 'licensee', ['detect', '--json', targetDir]).stdout
-    if (licenseeOutput == null) {
+  async identifyLicense (targetDir) {
+    const command = await commandExists(['licensee', 'licensee.bat'])
+    if (command === null) {
       throw new Error('Licensee not installed')
     }
-
+    const licenseeOutput = spawnSync(command, ['detect', '--json', targetDir]).stdout
+    if (licenseeOutput == null) {
+      throw new Error('Error executing licensee')
+    }
     const json = licenseeOutput.toString()
     return JSON.parse(json).licenses.map(function (license) { return license.spdx_id })
   }

lib/linguist.js

@@ -1,8 +1,8 @@
 // Copyright 2017 TODO Group. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-const isWindows = require('is-windows')
 const spawnSync = require('child_process').spawnSync
+const { commandExists } = require('./command_exists')
 
 class Linguist {
   /**
@@ -12,18 +12,20 @@ class Linguist {
    * Throws 'Linguist not installed' error if command line of 'linguist' is not available.
    *
    * @param {string} targetDir The directory to run linguist on
-   * @returns {object} The linguist output
+   * @returns {Promise<object>} The linguist output
    */
-  identifyLanguagesSync (targetDir) {
+  async identifyLanguages (targetDir) {
     // Command was renamed in https://github.com/github/linguist/pull/4208
-    for (const command of ['github-linguist', 'linguist']) {
-      const output = spawnSync(isWindows() ? `${command}.bat` : command, [targetDir, '--json']).stdout
-      if (output !== null) {
-        return JSON.parse(output.toString())
-      }
+    const command = await commandExists(['github-linguist', 'linguist', 'github-linguist.bat', 'linguist.bat'])
+    if (command === null) {
+      throw new Error('Linguist not installed')
+    }
+    const output = spawnSync(command, [targetDir, '--json']).stdout
+    if (output !== null) {
+      return JSON.parse(output.toString())
+    } else {
+      throw new Error('Execution of linguist failed!')
     }
-
-    throw new Error('Linguist not installed')
   }
 }
 

package.json

@@ -40,6 +40,7 @@
   "dependencies": {
     "ajv": "^6.12.4",
     "chalk": "^4.1.0",
+    "command-exists": "^1.2.9",
     "emoji-regex": "^9.0.0",
     "eslint-config-standard": "^14.1.1",
     "find-config": "^1.0.0",
@@ -63,7 +64,6 @@
     "chai-as-promised": "^7.1.1",
     "chai-each": "0.0.1",
     "chai-string": "^1.5.0",
-    "command-exists": "^1.2.9",
     "documentation": "^13.0.2",
     "eslint": "^7.7.0",
     "eslint-plugin-jsdoc": "^30.3.0",

tests/axioms/licensee_tests.js

@@ -15,18 +15,18 @@ describe('licensee', function () {
   } else {
     const licenseeAxiom = require('../../axioms/licensee')
 
-    it('runs licensee', () => {
+    it('runs licensee', async () => {
       const mockFs = { targetDir: path.resolve(__dirname, '../../') }
-      const res = licenseeAxiom(mockFs)
+      const res = await licenseeAxiom(mockFs)
 
       expect(res.passed).to.equal(true)
       expect(res.targets).to.have.length(1)
       expect(res.targets[0].path).to.equal('Apache-2.0')
     })
 
-    it('returns nothing if no licenses are found', () => {
+    it('returns nothing if no licenses are found', async () => {
       const mockFs = { targetDir: path.resolve(__dirname) }
-      const res = licenseeAxiom(mockFs)
+      const res = await licenseeAxiom(mockFs)
 
       expect(res.passed).to.equal(true)
       expect(res.targets).to.have.length(0)

tests/axioms/linguist_tests.js

@@ -15,9 +15,9 @@ describe('linguist', function () {
   } else {
     const linguistAxiom = require('../../axioms/linguist')
 
-    it('runs linguist', () => {
+    it('runs linguist', async () => {
       const mockFs = { targetDir: path.resolve(__dirname, '../../') }
-      const res = linguistAxiom(mockFs)
+      const res = await linguistAxiom(mockFs)
 
       expect(res.passed).to.equal(true)
       expect(res.targets).to.have.length.greaterThan(0)