fix(cli): rspack build --watch not work (#2280) (#2316)

.changeset/shaggy-hairs-float.md

@@ -0,0 +1,6 @@
+---
+"@rspack/core": patch
+"@rspack/cli": patch
+---
+
+fix(cli): rspack build --watch not work ([#2280](https://github.com/web-infra-dev/rspack/issues/2280))

packages/rspack-cli/src/commands/build.ts

@@ -3,7 +3,7 @@ import type { RspackCLI } from "../rspack-cli";
 import { RspackCommand } from "../types";
 import { commonOptions } from "../utils/options";
 import { Stats } from "@rspack/core/src/stats";
-import { Compiler } from "@rspack/core";
+import { Compiler, MultiCompiler } from "@rspack/core";
 import MultiStats from "@rspack/core/src/multiStats";
 
 export class BuildCommand implements RspackCommand {
@@ -86,11 +86,22 @@ export class BuildCommand implements RspackCommand {
 				console.time("build");
 				let rspackOptions = { ...options, argv: { ...options } };
 
-				const compiler = await cli.createCompiler(rspackOptions, "production");
-				compiler.run((err, Stats) => {
+				const errorHandler = (err, Stats) => {
 					callback(err, Stats);
 					console.timeEnd("build");
-				});
+				};
+
+				const compiler = await cli.createCompiler(
+					rspackOptions,
+					"production",
+					errorHandler
+				);
+
+				if (cli.isWatch(compiler)) {
+					return;
+				} else {
+					compiler.run(errorHandler);
+				}
 			}
 		);
 	}

packages/rspack-cli/src/rspack-cli.ts

@@ -9,7 +9,9 @@ import {
 	MultiCompiler,
 	Compiler,
 	rspack,
-	MultiRspackOptions
+	MultiRspackOptions,
+	Stats,
+	MultiStats
 } from "@rspack/core";
 import { normalizeEnv } from "./utils/options";
 import { loadRspackConfig } from "./utils/loadConfig";
@@ -25,7 +27,8 @@ export class RspackCLI {
 	}
 	async createCompiler(
 		options: RspackCLIOptions,
-		rspackEnv: RspackEnv
+		rspackEnv: RspackEnv,
+		callback?: (e: Error, res?: Stats | MultiStats) => void
 	): Promise<Compiler | MultiCompiler> {
 		process.env.RSPACK_CONFIG_VALIDATE = "loose";
 		let nodeEnv = process?.env?.NODE_ENV;
@@ -36,8 +39,13 @@ export class RspackCLI {
 		}
 		let config = await this.loadConfig(options);
 		config = await this.buildConfig(config, options, rspackEnv);
+
+		const isWatch = Array.isArray(config)
+			? (config as MultiRspackOptions).some(i => i.watch)
+			: (config as RspackOptions).watch;
+
 		// @ts-ignore
-		const compiler = rspack(config);
+		const compiler = rspack(config, isWatch ? callback : undefined);
 		return compiler;
 	}
 	createColors(useColor?: boolean): RspackCLIColors {
@@ -102,6 +110,10 @@ export class RspackCLI {
 					}
 				});
 			}
+			// cli --watch overrides the watch config
+			if (options.watch) {
+				item.watch = options.watch;
+			}
 			// auto set default mode if user config don't set it
 			if (!item.mode) {
 				item.mode = rspackEnv ?? "none";
@@ -228,6 +240,13 @@ export class RspackCLI {
 	): compiler is MultiCompiler {
 		return Boolean((compiler as MultiCompiler).compilers);
 	}
+	isWatch(compiler: Compiler | MultiCompiler): boolean {
+		return Boolean(
+			this.isMultipleCompiler(compiler)
+				? compiler.compilers.some(compiler => compiler.options.watch)
+				: compiler.options.watch
+		);
+	}
 }
 
 export function defineConfig(config: RspackOptions): RspackOptions {

packages/rspack/src/index.ts

@@ -4,4 +4,5 @@ export * from "./compilation";
 export * from "./config";
 export * from "./rspack";
 export * from "./stats";
+export * from "./multiStats";
 export * from "./chunk_group";

packages/rspack/src/multiStats.ts

@@ -148,3 +148,5 @@ export default class MultiStats {
 		return results.filter(Boolean).join("\n\n");
 	}
 }
+
+export { MultiStats };