webpack/test/ProfilingPlugin.test.js

"use strict";

require("./helpers/warmup-webpack");

const path = require("path");
const fs = require("graceful-fs");
const rimraf = require("rimraf");

describe("Profiling Plugin", () => {
	jest.setTimeout(120000);

	it("should handle output path with folder creation", (done) => {
		const webpack = require("../");

		const outputPath = path.join(__dirname, "js/profilingPath");
		const finalPath = path.join(outputPath, "events.json");
		let counter = 0;
		rimraf(outputPath, () => {
			const startTime = process.hrtime();
			const compiler = webpack({
				context: __dirname,
				entry: "./fixtures/a.js",
				output: {
					path: path.join(__dirname, "js/profilingOut")
				},
				plugins: [
					new webpack.debug.ProfilingPlugin({
						outputPath: finalPath
					}),
					{
						apply(compiler) {
							const hook = compiler.hooks.make;
							for (const { stage, order } of [
								{ stage: 0, order: 1 },
								{ stage: 1, order: 2 },
								{ stage: -1, order: 0 }
							]) {
								hook.tap(
									{
										name: "RespectStageCheckerPlugin",
										stage
									},
									// eslint-disable-next-line no-loop-func
									() => {
										expect(counter++).toBe(order);
									}
								);
							}
						}
					}
				],
				experiments: {
					backCompat: false
				}
			});
			compiler.run((err) => {
				if (err) return done(err);
				const testDuration = process.hrtime(startTime);
				if (!fs.existsSync(outputPath)) {
					return done(new Error("Folder should be created."));
				}

				const data = require(finalPath);

				const maxTs = data.reduce((max, entry) => Math.max(max, entry.ts), 0);
				const minTs = data[0].ts;
				const duration = maxTs - minTs;
				expect(duration).toBeLessThan(
					testDuration[0] * 1000000 + testDuration[1] / 1000
				);
				const cpuProfile = data.find((entry) => entry.name === "CpuProfile");
				expect(cpuProfile).toBeTypeOf("object");
				const profile = cpuProfile.args.data.cpuProfile;
				expect(profile.startTime).toBeGreaterThanOrEqual(minTs);
				expect(profile.endTime).toBeLessThanOrEqual(maxTs);
				done();
			});
		});
	});
});