fix regex and add AspellWorker unit tests

services/spelling/app/js/ASpellWorker.js

@@ -130,7 +130,7 @@ class ASpellWorker {
 
     this.pipe.stdout.setEncoding('utf8') // ensure utf8 output is handled correctly
     var output = ''
-    const endMarkerRegex = new RegExp('^[a-z][a-z]', 'm')
+    const endMarkerRegex = new RegExp('^[a-z][a-z]', 'gm')
     this.pipe.stdout.on('data', data => {
       // We receive the language code from Aspell as the end of data marker in
       // the data.  The input is a utf8 encoded string.

services/spelling/test/unit/js/ASpellWorkerTests.js

@@ -0,0 +1,112 @@
+/* eslint-disable
+    handle-callback-err,
+    no-undef
+*/
+// TODO: This file was created by bulk-decaffeinate.
+// Sanity-check the conversion and remove this comment.
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+const sinon = require('sinon')
+const chai = require('chai')
+const { should, expect, assert } = chai
+const SandboxedModule = require('sandboxed-module')
+const EventEmitter = require('events')
+
+describe('ASpellWorker', function () {
+  beforeEach(function () {
+    this.child_process = {}
+    return (this.ASpellWorker = SandboxedModule.require('../../../app/js/ASpellWorker', {
+      requires: {
+        'logger-sharelatex': {
+          log() { },
+          info() { },
+          err() { }
+        },
+        'metrics-sharelatex': {
+          gauge() { },
+          inc() { }
+        },
+        'child_process': this.child_process
+      }
+    }))
+  })
+
+  describe("creating a worker", function () {
+    beforeEach(function () {
+      this.pipe = {
+        'stdout': new EventEmitter(),
+        'stderr': { on: sinon.stub() },
+        'stdin': {on: sinon.stub() },
+        'on': sinon.stub(),
+        'pid': 12345
+      }
+      this.child_process.spawn = sinon.stub().returns(this.pipe)
+      this.pipe.stdout.setEncoding = sinon.stub()
+      worker = new this.ASpellWorker('en')
+
+    })
+
+    describe("with normal aspell output", function () {
+      beforeEach(function () {
+        this.callback = worker.callback = sinon.stub()
+        this.pipe.stdout.emit('data', '& hello\n')
+        this.pipe.stdout.emit('data', '& world\n')
+        this.pipe.stdout.emit('data', 'en\n')
+        this.pipe.stdout.emit('data', '& goodbye')
+      })
+
+      it('should call the callback', function() {
+        expect(this.callback.called).to.equal(true)
+        expect(this.callback.calledWith(null, "& hello\n& world\nen\n")).to.equal(true)
+      })
+    })
+
+    describe("with the aspell end marker split across chunks", function () {
+      beforeEach(function () {
+        this.callback = worker.callback = sinon.stub()
+        this.pipe.stdout.emit('data', '& hello\n')
+        this.pipe.stdout.emit('data', '& world\ne')
+        this.pipe.stdout.emit('data', 'n\n')
+        this.pipe.stdout.emit('data', '& goodbye')
+      })
+
+      it('should call the callback', function() {
+        expect(this.callback.called).to.equal(true)
+        expect(this.callback.calledWith(null, "& hello\n& world\nen\n")).to.equal(true)
+      })
+    })
+
+    describe("with the aspell end marker newline split across chunks", function () {
+      beforeEach(function () {
+        this.callback = worker.callback = sinon.stub()
+        this.pipe.stdout.emit('data', '& hello\n')
+        this.pipe.stdout.emit('data', '& world\n')
+        this.pipe.stdout.emit('data', 'en')
+        this.pipe.stdout.emit('data', '\n& goodbye')
+      })
+
+      it('should call the callback', function() {
+        expect(this.callback.called).to.equal(true)
+        expect(this.callback.calledWith(null, "& hello\n& world\nen")).to.equal(true)
+      })
+    })
+
+    describe("with everything split across chunks", function () {
+      beforeEach(function () {
+        this.callback = worker.callback = sinon.stub()
+        '& hello\n& world\nen\n& goodbye'.split('').forEach(x => {
+          this.pipe.stdout.emit('data', x)
+        })
+      })
+
+      it('should call the callback', function() {
+        expect(this.callback.called).to.equal(true)
+        expect(this.callback.calledWith(null, "& hello\n& world\nen")).to.equal(true)
+      })
+    })
+
+  })
+})