JestJS: Wrong mock to test rejected promise
1
I'm trying to test for the rejected promise in this function using jest:
example.js
import Db from '/lib/db'
const db = new Db()
export async function example (fileId) {
await db.connect()
const Gfs = db.gfs
return new Promise(async function (resolve, reject) {
Gfs.find(
{ _id: ObjectId(fileId) },
{ limit: 1 }
).toArray((err, files) => {
if (err) reject(Error(err))
// ...
})
})
}
My test returns the error TypeError: Cannot read property 'toArray' of undefined:
__mocks/db.js
export default class Db {
constructor (uri, callback) {
this.gfs = {
find: Db.find || jest.fn()
}
}
connect () {
return this
}
}
example.test.js
import { example } from 'example.js'
import Db from '/lib/db'
jest.mock('/lib/db')
const db = new Db()
test('should reject with error', () => {
let Gfs = db.gfs
Gfs.find = jest.fn(
() => ({
toArray: _ =>
})
)
expect.assertions(1)
return expect(example()).rejects.toThrow()
})
So I guess my mock is not correct. Why is find undefined in my mock?
This is how my db class looks like
db.js
export default class Db {
constructor (uri, callback) {
const mongo = process.env.MONGO || 'mongodb://localhost:27017'
this.mongodb = process.env.MONGO_DB || 'testing'
this.gfs = null
this.connection = MongoClient.connect(mongo, { useNewUrlParser: true })
this.connected = false
return this
}
async connect (msg) {
if (!this.connected) {
try {
this.connection = await this.connection
this.connection = this.connection.db(this.mongodb)
this.gfs = new mongo.GridFSBucket(this.connection)
this.connected = true
} catch (err) {
console.error('mongo connection error', err)
}
}
return this
}
}
javascript mongodb mocking jestjs es6-promise
asked 2 days ago
user3142695
1,630937119
add a comment |
1
I'm trying to test for the rejected promise in this function using jest:
example.js
import Db from '/lib/db'
const db = new Db()
export async function example (fileId) {
await db.connect()
const Gfs = db.gfs
return new Promise(async function (resolve, reject) {
Gfs.find(
{ _id: ObjectId(fileId) },
{ limit: 1 }
).toArray((err, files) => {
if (err) reject(Error(err))
// ...
})
})
}
My test returns the error TypeError: Cannot read property 'toArray' of undefined:
__mocks/db.js
export default class Db {
constructor (uri, callback) {
this.gfs = {
find: Db.find || jest.fn()
}
}
connect () {
return this
}
}
example.test.js
import { example } from 'example.js'
import Db from '/lib/db'
jest.mock('/lib/db')
const db = new Db()
test('should reject with error', () => {
let Gfs = db.gfs
Gfs.find = jest.fn(
() => ({
toArray: _ =>
})
)
expect.assertions(1)
return expect(example()).rejects.toThrow()
})
So I guess my mock is not correct. Why is find undefined in my mock?
This is how my db class looks like
db.js
export default class Db {
constructor (uri, callback) {
const mongo = process.env.MONGO || 'mongodb://localhost:27017'
this.mongodb = process.env.MONGO_DB || 'testing'
this.gfs = null
this.connection = MongoClient.connect(mongo, { useNewUrlParser: true })
this.connected = false
return this
}
async connect (msg) {
if (!this.connected) {
try {
this.connection = await this.connection
this.connection = this.connection.db(this.mongodb)
this.gfs = new mongo.GridFSBucket(this.connection)
this.connected = true
} catch (err) {
console.error('mongo connection error', err)
}
}
return this
}
}
javascript mongodb mocking jestjs es6-promise
asked 2 days ago
user3142695
1,630937119
add a comment |
1
1
1
I'm trying to test for the rejected promise in this function using jest:
example.js
import Db from '/lib/db'
const db = new Db()
export async function example (fileId) {
await db.connect()
const Gfs = db.gfs
return new Promise(async function (resolve, reject) {
Gfs.find(
{ _id: ObjectId(fileId) },
{ limit: 1 }
).toArray((err, files) => {
if (err) reject(Error(err))
// ...
})
})
}
My test returns the error TypeError: Cannot read property 'toArray' of undefined:
__mocks/db.js
export default class Db {
constructor (uri, callback) {
this.gfs = {
find: Db.find || jest.fn()
}
}
connect () {
return this
}
}
example.test.js
import { example } from 'example.js'
import Db from '/lib/db'
jest.mock('/lib/db')
const db = new Db()
test('should reject with error', () => {
let Gfs = db.gfs
Gfs.find = jest.fn(
() => ({
toArray: _ =>
})
)
expect.assertions(1)
return expect(example()).rejects.toThrow()
})
So I guess my mock is not correct. Why is find undefined in my mock?
This is how my db class looks like
db.js
export default class Db {
constructor (uri, callback) {
const mongo = process.env.MONGO || 'mongodb://localhost:27017'
this.mongodb = process.env.MONGO_DB || 'testing'
this.gfs = null
this.connection = MongoClient.connect(mongo, { useNewUrlParser: true })
this.connected = false
return this
}
async connect (msg) {
if (!this.connected) {
try {
this.connection = await this.connection
this.connection = this.connection.db(this.mongodb)
this.gfs = new mongo.GridFSBucket(this.connection)
this.connected = true
} catch (err) {
console.error('mongo connection error', err)
}
}
return this
}
}
javascript mongodb mocking jestjs es6-promise
asked 2 days ago
user3142695
1,630937119
I'm trying to test for the rejected promise in this function using jest:
example.js
import Db from '/lib/db'
const db = new Db()
export async function example (fileId) {
await db.connect()
const Gfs = db.gfs
return new Promise(async function (resolve, reject) {
Gfs.find(
{ _id: ObjectId(fileId) },
{ limit: 1 }
).toArray((err, files) => {
if (err) reject(Error(err))
// ...
})
})
}
My test returns the error TypeError: Cannot read property 'toArray' of undefined:
__mocks/db.js
export default class Db {
constructor (uri, callback) {
this.gfs = {
find: Db.find || jest.fn()
}
}
connect () {
return this
}
}
example.test.js
import { example } from 'example.js'
import Db from '/lib/db'
jest.mock('/lib/db')
const db = new Db()
test('should reject with error', () => {
let Gfs = db.gfs
Gfs.find = jest.fn(
() => ({
toArray: _ =>
})
)
expect.assertions(1)
return expect(example()).rejects.toThrow()
})
So I guess my mock is not correct. Why is find undefined in my mock?
This is how my db class looks like
db.js
export default class Db {
constructor (uri, callback) {
const mongo = process.env.MONGO || 'mongodb://localhost:27017'
this.mongodb = process.env.MONGO_DB || 'testing'
this.gfs = null
this.connection = MongoClient.connect(mongo, { useNewUrlParser: true })
this.connected = false
return this
}
async connect (msg) {
if (!this.connected) {
try {
this.connection = await this.connection
this.connection = this.connection.db(this.mongodb)
this.gfs = new mongo.GridFSBucket(this.connection)
this.connected = true
} catch (err) {
console.error('mongo connection error', err)
}
}
return this
}
}
javascript mongodb mocking jestjs es6-promise
javascript mongodb mocking jestjs es6-promise
asked 2 days ago
user3142695
1,630937119
asked 2 days ago
user3142695
1,630937119
edited 2 days ago
asked 2 days ago
user3142695
1,630937119
asked 2 days ago
user3142695
1,630937119
asked 2 days ago
user3142695
1,630937119
1,630937119
add a comment |
add a comment |
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