fixture-riveter

This section will help you set up a single fixture, load it, and use it in a test.

1. Installation

In these docs, we'll assume npm, but yarn works just as well.

npm install -D fixture-riveter
1
yarn add -D fixture-riveter
1

2. Create a fixture

Create a new folder, probably in your test folder, to hold the fixtures you define. Best practices is to make a separate fixture definition file for each model you'll need.

mkdir test/fixtures
1

In a file in that directory, import the model class you wish to create a fixture for and the fr instance from fixture-riveter. In the below example, we include an example model class for demonstration purposes.

// in lib/models/user.ts
class User {
    id: number;
    name: string;
    age: number;
    email: string;
}

// in test/fixtures/user.ts
import {fr} from "fixture-riveter";
import {User} from "../../lib/models/user";

fr.fixture("user", User, (f) => {
    f.attr("name", () => "Noah");
    f.attr("age", () => 32);
    f.sequence("email", (n) => `test${n}@foo.bar`);
});
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
// in lib/models/user.js
class User {}

// in test/fixtures/user.js
const fr = require("fixture-riveter").fr;
const User = require("../../lib/models/user").User;

fr.fixture("user", User, (f) => {
    f.attr("name", () => "Noah");
    f.attr("age", () => 32);
    f.sequence("email", (n) => `test${n}@foo.bar`);
});
1
2
3
4
5
6
7
8
9
10
11
12

3. Load fixture definitions

There are two options for loading fixtures:

  1. Manually import each fixture definition file individually
  2. Use the built-in async method loadFixtures to load every fixture in a given directory.

For the purposes of this tutorial, we'll assume you know how to manually import files. Because of how fixture-riveter is built, nothing needs to be done with the imported file, the very act of loading it loads the defined fixture.

To use the built-in method, import fr and call the method asynchronously, either in a jest/mocha/similar before block (so that happens before running any tests), or with a .then callback to handle the Promise. In either case, use a relative path from your project root, aka where you run npm test.

import {fr} from "fixture-riveter";

before(async function() {
    await fr.loadFixtures("test/fixtures");
});
1
2
3
4
5
const fr = require("fixture-riveter").fr;

before(async function() {
    await fr.loadFixtures("test/fixtures");
});
1
2
3
4
5

4. Using a fixture

Create a new test file in your test directory, adjacent other tests. Import fr from fixture-riveter, and in an async test, call the build method to generate an instance of the model that has not been saved to the database. The code below uses the testing library mocha and the assertion library chai, but any testing and assertion libraries will do.

import {fr} from "fixture-riveter";
import {it} from "mocha";
import {expect} from "chai";

it("builds an instance of the model", async function() {
    const user = await fr.build("user");

    expect(user.name).to.equal("Noah");
    expect(user.age).to.equal(32);
    expect(user.email).to.equal("test1@foo.bar");
});
1
2
3
4
5
6
7
8
9
10
11
const fr = require("fixture-riveter").fr;
const it = require("mocha").it;
const expect = require("chai").expect;

it("builds an instance of the model", async function() {
    const user = await fr.build("user");

    expect(user.name).to.equal("Noah");
    expect(user.age).to.equal(32);
    expect(user.email).to.equal("test1@foo.bar");
});
1
2
3
4
5
6
7
8
9
10
11

Further usage

For more examples, please check the Guideopen in new window. For a comprehensive tour of the internals, see the APIopen in new window. For discussions of design decisions and differences from the libraries that inspired fixture-riveter, Design Notesopen in new window.