Timeout issue with jestjs - jestjs

Question

I was using jest to write a test for a function and I keep getting hit with an exceeded timeout issue. I tried to solve this by adding a bigger number to the second parameter in my test function and also by changing my jest config settings in my package.json file but both did not work. Any help would be appreciated.
Test File
const favoriteBlog = require('../utils/list_helper').favoriteBlog
describe(("fav blog"), () => {
const listWithOneBlog = [
{
_id: "5a422a851b54a676234d17f7",
title: "React patterns",
author: "Michael Chan",
url: "https://reactpatterns.com/",
likes: 7,
__v: 0
},
{
_id: "5a422aa71b54a676234d17f8",
title: "Go To Statement Considered Harmful",
author: "Edsger W. Dijkstra",
url: "http://www.u.arizona.edu/~rubinson/copyright_violations/Go_To_Considered_Harmful.html",
likes: 5,
__v: 0
},
{
_id: "5a422b3a1b54a676234d17f9",
title: "Canonical string reduction",
author: "Edsger W. Dijkstra",
url: "http://www.cs.utexas.edu/~EWD/transcriptions/EWD08xx/EWD808.html",
likes: 12,
__v: 0
},
{
_id: "5a422b891b54a676234d17fa",
title: "First class tests",
author: "Robert C. Martin",
url: "http://blog.cleancoder.com/uncle-bob/2017/05/05/TestDefinitions.htmll",
likes: 10,
__v: 0
},
{
_id: "5a422ba71b54a676234d17fb",
title: "TDD harms architecture",
author: "Robert C. Martin",
url: "http://blog.cleancoder.com/uncle-bob/2017/03/03/TDD-Harms-Architecture.html",
likes: 0,
__v: 0
},
{
_id: "5a422bc61b54a676234d17fc",
title: "Type wars",
author: "Robert C. Martin",
url: "http://blog.cleancoder.com/uncle-bob/2016/05/01/TypeWars.html",
likes: 2,
__v: 0
}
]
test("find the blog with the most likes", (blog) => {
const expected = {
title: "Canonical string reduction",
author: "Edsger W. Dijkstra",
likes: 12
}
const result = favoriteBlog(listWithOneBlog)
expect(result).toEqual(expected)
})
})
Function File
const favoriteBlog = (blog) => {
console.log("before is",blog.map(a => a.likes) )
const preArray = blog.map(a => a.likes)
console.log("Math max thing is", Math.max(...preArray))
const objArr = Math.max(...preArray)
console.log("objArr is",objArr)
const favBlog = blog.filter((x) => x.likes == objArr);
const favBlogObj = favBlog[0]
delete favBlogObj._id;
delete favBlogObj.__v;
delete favBlogObj.url;
console.log("Fav blog is now",favBlog)
return favBlogObj
}
module.exports = {
favoriteBlog
}

Answer 1

The test is failing because you have a blog parameter on the test callback, which Jest interprets to be a callback function which you must call to end the test. The param is not used by the test, so I think this is a mistake and should be removed. If you intend to use the callback, then just add blog() as the last statement in the test (perhaps renaming it to done which is the convention).
Completion callbacks are used for some API styles, but in most cases you don't need this parameter and can just end the test, or return a Promise if you are expecting something to end later.
test("find the blog with the most likes", (blog) => {
// ^^^^ HERE
const expected = {
title: "Canonical string reduction",
author: "Edsger W. Dijkstra",
likes: 12
}
const result = favoriteBlog(listWithOneBlog)
expect(result).toEqual(expected)
})