Refactor resolver/spec

- favor transaction functions
- add errors undefined, clean up specs

backend/src/schema/resolvers/comments.js

@@ -5,6 +5,7 @@ export default {
   Mutation: {
     CreateComment: async (object, params, context, resolveInfo) => {
       const { postId } = params
+      const { user, driver } = context
       // Adding relationship from comment to post by passing in the postId,
       // but we do not want to create the comment with postId as an attribute
       // because we use relationships for this. So, we are deleting it from params
@@ -12,9 +13,11 @@ export default {
       delete params.postId
       params.id = params.id || uuid()
 
-      const session = context.driver.session()
+      const session = driver.session()
-      try {
+
-        const createCommentCypher = `
+      const writeTxResultPromise = session.writeTransaction(async transaction => {
+        const createCommentTransactionResponse = await transaction.run(
+          ` 
             MATCH (post:Post {id: $postId})
             MATCH (author:User {id: $userId})
             WITH post, author
@@ -23,15 +26,15 @@ export default {
             SET comment.updatedAt = toString(datetime())
             MERGE (post)<-[:COMMENTS]-(comment)<-[:WROTE]-(author)
             RETURN comment
-      `
+          `,
-        const transactionRes = await session.run(createCommentCypher, {
+          { userId: user.id, postId, params },
-          userId: context.user.id,
+        )
-          postId,
+        return createCommentTransactionResponse.records.map(
-          params,
+          record => record.get('comment').properties,
+        )
       })
-
+      try {
-        const [comment] = transactionRes.records.map(record => record.get('comment').properties)
+        const [comment] = await writeTxResultPromise
-
         return comment
       } finally {
         session.close()
@@ -39,15 +42,22 @@ export default {
     },
     UpdateComment: async (_parent, params, context, _resolveInfo) => {
       const session = context.driver.session()
-      try {
+      const writeTxResultPromise = session.writeTransaction(async transaction => {
-        const updateCommentCypher = `
+        const updateCommentTransactionResponse = await transaction.run(
+          ` 
             MATCH (comment:Comment {id: $params.id})
             SET comment += $params
             SET comment.updatedAt = toString(datetime())
             RETURN comment
-      `
+          `,
-        const transactionRes = await session.run(updateCommentCypher, { params })
+          { params },
-        const [comment] = transactionRes.records.map(record => record.get('comment').properties)
+        )
+        return updateCommentTransactionResponse.records.map(
+          record => record.get('comment').properties,
+        )
+      })
+      try {
+        const [comment] = await writeTxResultPromise
         return comment
       } finally {
         session.close()
@@ -55,8 +65,8 @@ export default {
     },
     DeleteComment: async (_parent, args, context, _resolveInfo) => {
       const session = context.driver.session()
-      try {
+      const writeTxResultPromise = session.writeTransaction(async transaction => {
-        const transactionRes = await session.run(
+        const deleteCommentTransactionResponse = await transaction.run(
           ` 
             MATCH (comment:Comment {id: $commentId})
             SET comment.deleted        = TRUE
@@ -66,7 +76,12 @@ export default {
           `,
           { commentId: args.id },
         )
-        const [comment] = transactionRes.records.map(record => record.get('comment').properties)
+        return deleteCommentTransactionResponse.records.map(
+          record => record.get('comment').properties,
+        )
+      })
+      try {
+        const [comment] = await writeTxResultPromise
         return comment
       } finally {
         session.close()

backend/src/schema/resolvers/comments.spec.js

@@ -10,7 +10,8 @@ const factory = Factory()
 
 let variables, mutate, authenticatedUser, commentAuthor, newlyCreatedComment
 
-beforeAll(() => {
+beforeAll(async () => {
+  await factory.cleanDatabase()
   const { server } = createServer({
     context: () => {
       return {
@@ -19,8 +20,7 @@ beforeAll(() => {
       }
     },
   })
-  const client = createTestClient(server)
+  mutate = createTestClient(server).mutate
-  mutate = client.mutate
 })
 
 beforeEach(async () => {
@@ -100,6 +100,7 @@ describe('CreateComment', () => {
         await expect(mutate({ mutation: createCommentMutation, variables })).resolves.toMatchObject(
           {
             data: { CreateComment: { content: "I'm authorised to comment" } },
+            errors: undefined,
           },
         )
       })
@@ -108,6 +109,7 @@ describe('CreateComment', () => {
         await expect(mutate({ mutation: createCommentMutation, variables })).resolves.toMatchObject(
           {
             data: { CreateComment: { author: { name: 'Author' } } },
+            errors: undefined,
           },
         )
       })
@@ -157,6 +159,7 @@ describe('UpdateComment', () => {
       it('updates the comment', async () => {
         const expected = {
           data: { UpdateComment: { id: 'c456', content: 'The comment is updated' } },
+          errors: undefined,
         }
         await expect(mutate({ mutation: updateCommentMutation, variables })).resolves.toMatchObject(
           expected,
@@ -172,6 +175,7 @@ describe('UpdateComment', () => {
               createdAt: expect.any(String),
             },
           },
+          errors: undefined,
         }
         await expect(mutate({ mutation: updateCommentMutation, variables })).resolves.toMatchObject(
           expected,