Error handling by events. Execute event has been moved to manager.

src/cli.js

@@ -1,10 +1,7 @@
-const {parse, parseCommand, tokensToCommand} = require('./parser')
-const {Manager} = require('./manager')
+const {parse, parseCommand, tokensToCommand, extractValue} = require('./parser')
+const {Manager, EVENTS} = require('./manager')
 const readline = require('readline')
 const EventEmmiter = require('events')
-const EVENTS = {
-  commandExecuted: 'commandExecuted'
-}
 
 const commands = [
   // List commands.
@@ -110,7 +107,15 @@ function runCommand(_commands, injection = null, tokens) {
     injection = _injection
   }
   const manager = new Manager(allCommands, injection)
-  const request = tokensToCommand(tokens)
+  manager.events.on(EVENTS.error, ({e, request}) => {
+    const { console } = injection
+    console.log(e.toString())
+    const stack = extractValue(request.args, 'stack', false)
+    if (stack) {
+      console.log(e.stack)
+    }
+  })
+  request = tokensToCommand(tokens)
 
   return manager.execute(request)
 }

src/manager.js

@@ -1,6 +1,7 @@
 const EventEmitter = require('events')
 const EVENTS = {
-  onError: 'onError'
+  error: 'error',
+  executed: 'executed'
 }
 
 class Manager {
@@ -10,13 +11,16 @@ class Manager {
     this.events = new EventEmitter()
   }
 
-  execute(request) {
+  async execute(request) {
     const command = this.get(request)
     try {
-      return command.handler({command, request, injection: this.injection, manager: this})
+      const result = await command.handler({command, request, injection: this.injection, manager: this})
+      this.events.emit(EVENTS.executed, { request, result })
+
+      return result
     }
     catch(e) {
-      this.events.emit(EVENTS.onError, e)
+      this.events.emit(EVENTS.error, {e, request})
     }
   }
 

test/cli.spec.js

@@ -16,8 +16,6 @@ describe('Commander', () => {
           title: 'Prints values',
           handler: async ({ injection: { console } }) => {
             console.log('Run commander testing.')
-
-            return true
           }
         },
       ],
@@ -29,6 +27,41 @@ describe('Commander', () => {
     const line = _console.objects.pop()
     assert.equal(line, 'Run commander testing.')
   })
+
+  describe('Handle error message', async () => {
+    const runWithError = async (tokens) => {
+      await runCommand(
+        [
+          {
+            name: 'print',
+            title: 'Prints values',
+            handler: async ({ injection: { console } }) => {
+              throw new Error('Printer does not work.')
+            }
+          },
+        ],
+        {
+          console: _console
+        },
+        tokens
+      )
+    }
+
+    it('Error', async () => {
+      await runWithError(['print'])
+      const line = _console.objects.pop()
+      const etalon = 'Error: Printer does not work.'
+      assert.equal(line, etalon)
+    })
+
+    it('Error with stack', async () => {
+      await runWithError(['print', '--stack'])
+      const lines = _console.objects.pop().split('\n')
+      const etalon = 'Error: Printer does not work.'
+      assert.equal(lines[0], etalon)
+      assert.notEqual(lines[6].match(/at callFn/i), null)
+    })
+  })
 })
 
 describe('CLI', () => {

test/manager.spec.js

@@ -1,7 +1,7 @@
 const assert = require('assert')
 const { Manager, EVENTS } = require('../src/manager')
 
-describe('CLI commander testing', () => {
+describe('Command manager testing', () => {
   let manager
   const injection = {
     time: 'timeString'
@@ -62,15 +62,29 @@ describe('CLI commander testing', () => {
     assert.equal(command.group, 'default')
   })
 
-  it('Error invoking command.', (done) => {
-    const request = {
-      name: 'invokeError',
-    }
-    manager.events.once(EVENTS.onError, (e) => {
-      assert.equal('Test error.', e.message)
-      done()
+  describe('Events', () => {
+    it('Error invoking command.', (done) => {
+      const request = {
+        name: 'invokeError',
+      }
+      manager.events.once(EVENTS.error, ({e, request: _request}) => {
+        assert.equal('Test error.', e.message)
+        assert.equal(request.name, _request.name)
+        done()
+      })
+      manager.execute(request)
+    })
+
+    it('Executed', (done) => {
+      const request = {
+        name: 'command',
+      }
+      manager.events.once(EVENTS.executed, ({request: _request}) => {
+        assert.equal(request.name, _request.name)
+        done()
+      })
+      manager.execute(request)
     })
-    manager.execute(request)
   })
 
   it('Get', () => {