Fixes ctdio#16 - Implement command line argument parsing using argly.

README.md

@@ -24,7 +24,21 @@ To run your tests, you can pass in the test files to the exposed cli tool. A glo
 on the shell you are using.
 
 ```
-npx mocha-puppeteer ./tests/*.js
+Usage: mocha-puppeteer [OPTIONS]
+
+Examples:
+
+   Test a single file: "mocha-puppeteer /foo/bar-test.js"
+
+   Test a series of files using a glob pattern: "mocha-puppeteer /foo/**/*-test.js"
+
+Options:
+
+     --help -h Show this help message [string]
+
+  --version -v Show the version number of mocha-puppeteer [string]
+
+--pattern -p * Pattern to run tests. Either a single file or glob pattern. [string]
 ```
 
 ## Contributing

bin/mocha-puppeteer

@@ -1,3 +1,11 @@
 #!/usr/bin/env node
+const cli = require('../cli')
 
-require('../cli')()
+;(async () => {
+  try {
+    await cli()
+  } catch (err) {
+    console.error(err)
+    process.exit(1)
+  }
+})()

cli.js

@@ -1,7 +1,8 @@
+const argly = require('argly')
 const mochaPuppeteer = require('./index')
 const _loadConfig = require('./src/utils/loadConfig')
 
-const args = process.argv.slice(2)
+const mochaPuppeteerPkgVersion = require('./package.json').version
 
 // pick specific values from config
 function _pickConfig (config) {
@@ -11,17 +12,56 @@ function _pickConfig (config) {
   /* eslint-enable */
 }
 
+const parser = argly
+  .createParser({
+    '--help -h': {
+      type: 'string',
+      description: 'Show this help message'
+    },
+    '--version -v': {
+      type: 'string',
+      description: 'Show the version number of mocha-puppeteer'
+    },
+    '--pattern -p *': {
+      type: 'string',
+      description: 'Pattern to run tests. Either a single file or glob pattern.'
+    }
+  })
+  .example('Test a single file: "mocha-puppeteer /foo/bar-test.js"')
+  .example('Test a series of files using a glob pattern: "mocha-puppeteer /foo/*/*-test.js"')
+  .validate(function (result) {
+    if (result.help) {
+      this.printUsage()
+    } else if (result.version) {
+      console.log(`mocha-puppeteer@${mochaPuppeteerPkgVersion}`)
+    } else if (!result.pattern) {
+      this.printUsage()
+    }
+  })
+  .onError(function (err) {
+    this.printUsage()
+    throw new Error('Error parsing command line args: ', err)
+  })
+
 module.exports = async function runCli () {
+  const {
+    pattern,
+    help,
+    version
+  } = parser.parse()
+
+  // Gracefully exit if either the "help" or "version" arguments are supplied
+  // of if the "pattern" argument is missing because it's required.
+  if (help || version || !pattern) return
+
   try {
     const config = await _loadConfig({
       startingDirectory: process.cwd()
     })
 
     const options = config ? _pickConfig(config) : {}
 
-    Object.assign(options, {
-      testFiles: args
-    })
+    Object.assign(options, { testFiles: [ pattern ] })
 
     await mochaPuppeteer.runTests(options)
   } catch (err) {

package.json

@@ -17,6 +17,7 @@
   "author": "Charlie Duong",
   "license": "MIT",
   "dependencies": {
+    "argly": "^1.2.0",
     "babel-plugin-istanbul": "^4.1.4",
     "bluebird": "^3.5.0",
     "koa": "^2.3.0",