Similar to a previous question, I am trying to mock an external library using sinon. However, the library exports two functions and a namespace using the same name FastGlob.
I have a basic understanding of function overloading but i'm not sure how namespaces work with function overloading or if this issue is even related.
Regardless, I want to mock the first function definition but sinon is seeing the namespace
declare function FastGlob(source: PatternInternal | PatternInternal[], options: OptionsInternal & EntryObjectPredicate): Promise<EntryInternal[]>;
Here is the libraries definition file
import { Options as OptionsInternal } from './settings';
import { Entry as EntryInternal, FileSystemAdapter as FileSystemAdapterInternal, Pattern as PatternInternal } from './types';
declare function FastGlob(source: PatternInternal | PatternInternal[], options: OptionsInternal & EntryObjectPredicate): Promise<EntryInternal[]>;
declare function FastGlob(source: PatternInternal | PatternInternal[], options?: OptionsInternal): Promise<string[]>;
declare namespace FastGlob {
type Options = OptionsInternal;
type Entry = EntryInternal;
type Task = taskManager.Task;
type Pattern = PatternInternal;
type FileSystemAdapter = FileSystemAdapterInternal;
function sync(source: PatternInternal | PatternInternal[], options: OptionsInternal & EntryObjectPredicate): EntryInternal[];
function sync(source: PatternInternal | PatternInternal[], options?: OptionsInternal): string[];
function stream(source: PatternInternal | PatternInternal[], options?: OptionsInternal): NodeJS.ReadableStream;
function generateTasks(source: PatternInternal | PatternInternal[], options?: OptionsInternal): Task[];
function isDynamicPattern(source: PatternInternal, options?: OptionsInternal): boolean;
function escapePath(source: PatternInternal): PatternInternal;
}
export = FastGlob;
I've tried using variations of the following test but TS complains it can only find the functions within the namespace (sync, stream, etc...). Removing the string name of the function causes a different issue.
import * as FastGlob from 'fast-glob';
import { stub, SinonStub } from "sinon";
import { Pattern, Entry, Options } from "fast-glob";
(stub(FastGlob, "FastGlob") as unknown as SinonStub<[s: Pattern | Pattern[], o: Options], Promise<Entry[]>>).resolves([{test: '/test/'} as unknown as Entry])
The application code is being used like so
import * as glob from 'fast-glob';
const paths: Array<string> = await glob('./my/glob/**/*.ts', { absolute: true });
You need additional module to stub fast-glob, because the way it defined. For more info, you can look at this sinon issue.
I can give you example if you can use additional module: proxyquire.
I have this glob.ts.
// File: glob.ts
import glob from 'fast-glob';
async function getPaths(input: string): Promise<Array<glob.Entry|string>> {
return glob(input, { absolute: true });
}
export { getPaths };
Test using spec file:
// File: glob.spec.ts
import * as FastGlob from 'fast-glob';
import sinon from 'sinon';
import proxyquire from 'proxyquire';
import { expect } from 'chai';
describe('Glob', () => {
const fakeInput = './node_modules/**/settings.js';
it('getPaths using first fast-glob definition', async () => {
const fakeResult = [{ test: '/test/' } as unknown as FastGlob.Entry];
const fakeFunc = sinon.fake.resolves(fakeResult);
// Create stub using proxyquire.
const glob = proxyquire('./glob', {
'fast-glob': sinon.fake.resolves(fakeResult),
});
const paths = await glob.getPaths(fakeInput);
expect(paths).to.deep.equal(fakeResult);
expect(fakeFunc.calledOnceWithExactly(fakeInput));
})
it('getPaths using second fast-glob definition', async () => {
const fakeResult = ['/test/'];
const fakeFunc = sinon.fake.resolves(fakeResult);
// Create stub using proxyquire.
const glob = proxyquire('./glob', {
'fast-glob': sinon.fake.resolves(fakeResult),
});
const paths = await glob.getPaths(fakeInput);
expect(paths).to.deep.equal(fakeResult);
expect(fakeFunc.calledOnceWithExactly(fakeInput));
})
});
When you run it using ts-mocha and nyc from terminal:
$ npx nyc ts-mocha glob.spec.ts
Glob
✔ getPaths using first fast-glob definition (137ms)
✔ getPaths using second fast-glob definition
2 passing (148ms)
--------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
glob.spec.ts | 100 | 100 | 100 | 100 |
glob.ts | 100 | 100 | 100 | 100 |
--------------|---------|----------|---------|---------|-------------------