microsoft/typespec
Publicmirrored from https://github.com/microsoft/typespecAvailable
packages/internal-build-utils/src/watch.ts
56lines · modecode
| 1 | import chokidar from "chokidar"; |
| 2 | import { resolve } from "path"; |
| 3 | import { clearScreen, logWithTime } from "./common.js"; |
| 4 | |
| 5 | export function runWatch(pattern: string, build: any, options?: any) { |
| 6 | let lastBuildTime: Date; |
| 7 | pattern = resolve(pattern); |
| 8 | |
| 9 | start(); |
| 10 | |
| 11 | function start() { |
| 12 | // build once up-front |
| 13 | runBuild(); |
| 14 | |
| 15 | const watcher = chokidar.watch(pattern, { interval: 0.2, ...options }); |
| 16 | |
| 17 | // then build again on any change |
| 18 | watcher.on("add", (file) => runBuild(`${file} created`)); |
| 19 | watcher.on("removed", (file) => runBuild(`${file} removed`)); |
| 20 | watcher.on("change", (file, stats) => runBuild(`${file} changed`, stats?.mtime)); |
| 21 | } |
| 22 | |
| 23 | function runBuild(changeDescription?: string, changeTime?: Date) { |
| 24 | runBuildAsync(changeDescription, changeTime).catch((err) => { |
| 25 | // eslint-disable-next-line no-console |
| 26 | console.error(err.stack); |
| 27 | process.exit(1); |
| 28 | }); |
| 29 | } |
| 30 | |
| 31 | async function runBuildAsync(changeDescription?: string, changeTime?: Date) { |
| 32 | if (changeTime && lastBuildTime && changeTime < lastBuildTime) { |
| 33 | // Don't rebuild if a change happened before the last build kicked off. |
| 34 | // Defends against duplicate events and building more than once when a |
| 35 | // bunch of files are changed at the same time. |
| 36 | return; |
| 37 | } |
| 38 | |
| 39 | lastBuildTime = new Date(); |
| 40 | if (changeDescription) { |
| 41 | clearScreen(); |
| 42 | logWithTime(`File change detected: ${changeDescription}. Running build.`); |
| 43 | } else { |
| 44 | logWithTime("Starting build in watch mode."); |
| 45 | } |
| 46 | |
| 47 | try { |
| 48 | await build(); |
| 49 | logWithTime("Build succeeded. Waiting for file changes."); |
| 50 | } catch (err: any) { |
| 51 | // eslint-disable-next-line no-console |
| 52 | console.error(err.stack); |
| 53 | logWithTime(`Build failed. Waiting for file changes.`); |
| 54 | } |
| 55 | } |
| 56 | } |
| 57 | |