test.ts

// @ts-ignore @types/memfs does not exist
import {createFsFromVolume, Volume} from "memfs";
import path from "path";

// Create a mocked filesystem instance
const mockFs = createFsFromVolume(Volume.fromJSON({}));
jest.mock("fs", () => mockFs);

// Import modules that should be using the mocked filesystem
import {proteus} from "@proteus/core";
import {ProjectStructure} from "../src";

interface IDir { [name: string]: IDir | string; }
const jsonToMockFS = (cwd: string, dir: IDir): void => Object.keys(dir)
    .map((name: string): [string, IDir | string] => ([name, dir[name]]))
    .forEach(([name, value]: [string, IDir | string]) => {
        const p = path.resolve(cwd, name);
        if (typeof value === "string") {
            mockFs.writeFileSync(p, value);
        } else {
            mockFs.mkdirpSync(p);
            jsonToMockFS(p, value);
        }
    });

describe("ProjectStructurePlugin", () => {
    describe(".npmrc", () => {
        beforeAll(() => {
            jsonToMockFS("/", {
                "npmrc-test": {
                    "artifact1": {},
                    "artifact2": {
                        ".npmrc": "mock content 1"
                    }
                }
            });

            return proteus({
                workingDirectory: "/npmrc-test",
                plugins: [ProjectStructure]
            });
        });

        it("does not overwrite existing .npmrc files", () => {
            expect(mockFs.readFileSync(path.resolve("/npmrc-test/artifact2", ".npmrc")).toString())
                .toBe("mock content 1");
        });

        it("creates a new npmrc when one doesn't exist", () => {
            expect(mockFs.readFileSync(path.resolve("/npmrc-test/artifact1", ".npmrc")).toString())
                .toBe("registry=https://cernerrepos.net/api/npm/npm\npackage-lock=false\n");
        });
    });
});