don't learn the same word twice

services/spelling/app/js/LearnedWordsManager.js

@@ -15,7 +15,7 @@ const LearnedWordsManager = {
         token: userToken
       },
       {
-        $push: { learnedWords: word }
+        $addToSet: { learnedWords: word }
       },
       {
         upsert: true

services/spelling/test/acceptance/js/LearnTest.js

@@ -27,18 +27,37 @@ const unlearnWord = word =>
     })
   })
 
+const getDict = () =>
+  request.get({
+    url: `/user/${USER_ID}`
+  })
+
 const deleteDict = () =>
   request.del({
     url: `/user/${USER_ID}`
   })
 
 describe('learning words', function() {
-  it('should return status 204 when posting a word successfully', async function () {
+  afterEach(async function() {
+    await deleteDict()
+  })
+
+  it('should return status 204 when posting a word successfully', async function() {
     const response = await learnWord('abcd')
     expect(response.statusCode).to.equal(204)
   })
 
-  it('should return no misspellings after a word is learnt', async function () {
+  it('should not learn the same word twice', async function() {
+    await learnWord('foobar')
+    const learnResponse = await learnWord('foobar')
+    expect(learnResponse.statusCode).to.equal(204)
+
+    const dictResponse = await getDict()
+    const responseBody = JSON.parse(dictResponse.body)
+    expect(responseBody.length).to.equals(1)
+  })
+
+  it('should return no misspellings after a word is learnt', async function() {
     const response = await checkWord(['abv'])
     const responseBody = JSON.parse(response.body)
     expect(responseBody.misspellings.length).to.equals(1)
@@ -50,7 +69,7 @@ describe('learning words', function() {
     expect(responseBody2.misspellings.length).to.equals(0)
   })
 
-  it('should return misspellings again after a personal dictionary is deleted', async function () {
+  it('should return misspellings again after a personal dictionary is deleted', async function() {
     await learnWord('bvc')
     await deleteDict()
 
@@ -61,12 +80,12 @@ describe('learning words', function() {
 })
 
 describe('unlearning words', function() {
-  it('should return status 204 when posting a word successfully', async function () {
+  it('should return status 204 when posting a word successfully', async function() {
     const response = await unlearnWord('anything')
     expect(response.statusCode).to.equal(204)
   })
 
-  it('should return misspellings after a word is unlearnt', async function () {
+  it('should return misspellings after a word is unlearnt', async function() {
     await learnWord('abv')
 
     const response = await checkWord(['abv'])

services/spelling/test/unit/js/LearnedWordsManagerTests.js

@@ -51,7 +51,7 @@ describe('LearnedWordsManager', function() {
             token: this.token
           },
           {
-            $push: { learnedWords: this.word }
+            $addToSet: { learnedWords: this.word }
           },
           {
             upsert: true