feat:suggest matching commands if the user mistypes 🚧 (#181)

package.json

@@ -45,6 +45,7 @@
     "@babel/runtime": "^7.2.0",
     "async": "^2.0.0-rc.1",
     "chalk": "^2.3.0",
+    "didyoumean": "^1.2.1",
     "inquirer": "^6.2.1",
     "lodash": "^4.11.2",
     "pify": "^4.0.1",

src/cli.js

@@ -5,6 +5,10 @@ const path = require('path')
 const yargs = require('yargs')
 const chalk = require('chalk')
 const inquirer = require('inquirer')
+const didYouMean = require('didyoumean')
+
+// Setting edit length to be 60% of the input string's length
+didYouMean.threshold = 0.6
 
 const init = require('./init')
 const generate = require('./generate')
@@ -46,6 +50,15 @@ const yargv = yargs
     }
   }).argv
 
+function suggestCommands(cmd) {
+  const availableCommands = ['generate', 'add', 'init', 'check']
+  const suggestion = didYouMean(cmd, availableCommands)
+
+  if (suggestion) {
+    console.log(chalk.bold(`Did you mean ${suggestion}`))
+  }
+}
+
 function startGeneration(argv) {
   return Promise.all(
     argv.files.map(file => {
@@ -170,6 +183,7 @@ promptForCommand(yargv)
       case 'check':
         return checkContributors(yargv)
       default:
+        suggestCommands(command)
         throw new Error(`Unknown command ${command}`)
     }
   })