webpack/test/Compiler-caching.test.js

/* globals describe, it, before, after */
"use strict";

const path = require("path");
const fs = require("fs");

const webpack = require("../");
const WebpackOptionsDefaulter = require("../lib/WebpackOptionsDefaulter");

describe("Compiler (caching)", () => {
	jest.setTimeout(15000);

	function compile(entry, options, callback) {
		options.mode = "none";
		options = new WebpackOptionsDefaulter().process(options);
		options.cache = true;
		options.entry = entry;
		options.optimization.minimize = false;
		options.context = path.join(__dirname, "fixtures");
		options.output.path = "/";
		options.output.filename = "bundle.js";
		options.output.pathinfo = true;
		const logs = {
			mkdirp: [],
			writeFile: [],
		};

		const c = webpack(options);
		const files = {};
		c.outputFileSystem = {
			join() {
				return [].join.call(arguments, "/").replace(/\/+/g, "/");
			},
			mkdirp(path, callback) {
				logs.mkdirp.push(path);
				callback();
			},
			writeFile(name, content, callback) {
				logs.writeFile.push(name, content);
				files[name] = content.toString("utf-8");
				callback();
			}
		};
		c.hooks.compilation.tap("CompilerCachingTest", (compilation) => compilation.bail = true);

		let compilerIteration = 1;

		function runCompiler(options, callback) {
			if(typeof options === "function") {
				callback = options;
				options = {};
			}
			c.run((err, stats) => {
				if(err) throw err;
				expect(typeof stats).toBe("object");
				stats = stats.toJson({
					modules: true,
					reasons: true
				});
				expect(typeof stats).toBe("object");
				expect(stats).toHaveProperty("errors");
				expect(Array.isArray(stats.errors)).toBe(true);
				if(options.expectErrors) {
					expect(stats.errors).toHaveLength(options.expectErrors);
				} else {
					if(stats.errors.length > 0) {
						expect(typeof stats.errors[0]).toBe("string");
						throw new Error(stats.errors[0]);
					}
				}
				stats.logs = logs;
				callback(stats, files, compilerIteration++);
			});
		}

		runCompiler(callback);

		return {
			compilerInstance: c,
			runAgain: runCompiler
		};
	}

	const tempFixturePath = path.join(__dirname, "fixtures", "temp-cache-fixture");
	const aFilepath = path.join(tempFixturePath, "a.js");
	const cFilepath = path.join(tempFixturePath, "c.js");

	function cleanup() {
		function ignoreENOENT(fn) {
			try {
				return fn();
			} catch(e) {
				if(e.code !== "ENOENT") {
					throw e;
				}
			}
		}
		ignoreENOENT(() => fs.unlinkSync(aFilepath));
		ignoreENOENT(() => fs.unlinkSync(cFilepath));
		ignoreENOENT(() => fs.rmdirSync(tempFixturePath));
	}
	beforeAll(cleanup);
	afterAll(cleanup);

	function createTempFixture() {

		// Remove previous copy if present
		try {
			if(fs.statSync(tempFixturePath)) {
				fs.unlinkSync(aFilepath);
				fs.unlinkSync(cFilepath);
				fs.rmdirSync(tempFixturePath);
			}
		} catch(e) {
			if(e.code !== "ENOENT") {
				throw e;
			}
		}

		// Copy over file since we"ll be modifying some of them
		fs.mkdirSync(tempFixturePath);
		fs.createReadStream(path.join(__dirname, "fixtures", "a.js")).pipe(fs.createWriteStream(aFilepath));
		fs.createReadStream(path.join(__dirname, "fixtures", "c.js")).pipe(fs.createWriteStream(cFilepath));

		return {
			rootPath: tempFixturePath,
			aFilepath: aFilepath,
			cFilepath: cFilepath
		};
	}

	it("should cache single file (with manual 1s wait) ", (done) => {

		const options = {};
		const tempFixture = createTempFixture();

		const helper = compile("./temp-cache-fixture/c", options, (stats, files) => {

			// Not cached the first time
			expect(stats.assets[0].name).toBe("bundle.js");
			expect(stats.assets[0].emitted).toBe(true);

			helper.runAgain((stats, files, iteration) => {

				// Cached the second run
				expect(stats.assets[0].name).toBe("bundle.js");
				expect(stats.assets[0].emitted).toBe(false);

				const aContent = fs.readFileSync(tempFixture.aFilepath).toString().replace("This is a", "This is a MODIFIED");

				setTimeout(() => {
					fs.writeFileSync(tempFixture.aFilepath, aContent);

					helper.runAgain((stats, files, iteration) => {

						// Cached the third run
						expect(stats.assets[0].name).toBe("bundle.js");
						expect(stats.assets[0].emitted).toBe(true);

						done();
					});

				}, 1100);
			});
		});
	});

	it("should cache single file (even with no timeout) ", (done) => {

		const options = {};
		const tempFixture = createTempFixture();

		const helper = compile("./temp-cache-fixture/c", options, (stats, files) => {

			// Not cached the first time
			expect(stats.assets[0].name).toBe("bundle.js");
			expect(stats.assets[0].emitted).toBe(true);

			helper.runAgain((stats, files, iteration) => {
				// Cached the second run
				expect(stats.assets[0].name).toBe("bundle.js");
				expect(stats.assets[0].emitted).toBe(false);

				expect(files["/bundle.js"]).toMatch("This is a");

				const aContent = fs.readFileSync(tempFixture.aFilepath).toString().replace("This is a", "This is a MODIFIED");

				fs.writeFileSync(tempFixture.aFilepath, aContent);

				helper.runAgain((stats, files, iteration) => {

					// Cached the third run
					expect(stats.assets[0].name).toBe("bundle.js");
					expect(stats.assets[0].emitted).toBe(true);

					expect(files["/bundle.js"]).toMatch("This is a MODIFIED");

					done();
				});
			});
		});
	});

	it("should only build when modified (with manual 2s wait)", (done) => {

		const options = {};
		const tempFixture = createTempFixture();

		const helper = compile("./temp-cache-fixture/c", options, (stats, files) => {

			// Built the first time
			expect(stats.modules[0].name).toMatch("c.js");
			expect(stats.modules[0].built).toBe(true);

			expect(stats.modules[1].name).toMatch("a.js");
			expect(stats.modules[1].built).toBe(true);

			setTimeout(() => {
				helper.runAgain((stats, files, iteration) => {

					// Not built when cached the second run
					expect(stats.modules[0].name).toMatch("c.js");
					// expect(stats.modules[0].built).toBe(false);

					expect(stats.modules[1].name).toMatch("a.js");
					// expect(stats.modules[1].built).toBe(false);

					const aContent = fs.readFileSync(tempFixture.aFilepath).toString().replace("This is a", "This is a MODIFIED");

					setTimeout(() => {
						fs.writeFileSync(tempFixture.aFilepath, aContent);

						helper.runAgain((stats, files, iteration) => {

							// And only a.js built after it was modified
							expect(stats.modules[0].name).toMatch("c.js");
							expect(stats.modules[0].built).toBe(false);

							expect(stats.modules[1].name).toMatch("a.js");
							expect(stats.modules[1].built).toBe(true);

							done();
						});
					}, 2100);
				});
			}, 4100);
		});
	});

	it("should build when modified (even with no timeout)", (done) => {

		const options = {};
		const tempFixture = createTempFixture();

		const helper = compile("./temp-cache-fixture/c", options, (stats, files) => {

			// Built the first time
			expect(stats.modules[0].name).toMatch("c.js");
			expect(stats.modules[0].built).toBe(true);

			expect(stats.modules[1].name).toMatch("a.js");
			expect(stats.modules[1].built).toBe(true);

			helper.runAgain((stats, files, iteration) => {

				// Not built when cached the second run
				expect(stats.modules[0].name).toMatch("c.js");
				// expect(stats.modules[0].built).toBe(false);

				expect(stats.modules[1].name).toMatch("a.js");
				// expect(stats.modules[1].built).toBe(false);

				const aContent = fs.readFileSync(tempFixture.aFilepath).toString().replace("This is a", "This is a MODIFIED");

				fs.writeFileSync(tempFixture.aFilepath, aContent);

				helper.runAgain((stats, files, iteration) => {

					// And only a.js built after it was modified
					expect(stats.modules[0].name).toMatch("c.js");
					// expect(stats.modules[0].built).toBe(false);

					expect(stats.modules[1].name).toMatch("a.js");
					expect(stats.modules[1].built).toBe(true);

					done();
				});
			});
		});
	});
});