feat(eater): Send eater:finish event when process will be finished

lib/eater.js

@@ -38,6 +38,7 @@ class Eater extends EventEmitter {
     this.reporter.reportFileNumber(this.fileNum);
     const currentFiles = this.files.splice(0, this.procs);
     this.on('next', this.nextTest);
+    this.on('finish', (hasAnyError) => process.emit('eater:finish', hasAnyError));
     currentFiles.forEach((file) => this.emit('next', file));
 
   }
@@ -98,6 +99,7 @@ class Eater extends EventEmitter {
 
         }
         this.reporter.reportFinish(this.hasAnyError, this.errors);
+        this.emit('finish', this.hasAnyError);
 
       }
 

test/core/lib/eater/onEaterFinish.js

@@ -0,0 +1,38 @@
+'use strict';
+const assert = require('power-assert');
+const mustCall = require('must-call');
+const Eater = require(`${process.cwd()}/lib/eater`);
+const mockReporter = {
+  setChildProc: (child) => {
+    // do nothing
+  },
+  reportFileNumber: () => {
+    // do nothing
+  },
+  reportTestName: (name) => {
+    // do nothing
+  },
+  reportSubTestName: (name, parent) => {
+    // do nothing
+  },
+  reportSubSuccess: (name) => {
+    // do nothing
+  },
+  reportFinish: (name) => {
+    // do nothing
+  },
+  reportSuccess: (name) => {
+    // do nothing
+  },
+};
+const eater = new Eater({
+  reporter: mockReporter, 
+  dir: 'test/fixture', 
+  ext: 'success.js',
+});
+eater.eat();
+
+process.on('eater:finish', mustCall((hasAnyError) => {
+  assert(!hasAnyError);
+}));
+