parallelize build codes

Author: neverRare

build/dev.ts

@@ -1,5 +1,6 @@
 // This code is Deno only
 
+import { assert } from "@std/assert/assert";
 import { exists } from "@std/fs/exists";
 import * as ESBuild from "esbuild";
 import { OPTIONS } from "./config.ts";
@@ -9,11 +10,12 @@ const BUILD_OPTIONS: ESBuild.BuildOptions = {
   minify: false,
   define: { LIVE_RELOAD: "true" },
 };
-if (import.meta.main) {
-  if (!await exists(new URL("../dictionary/dictionary.ts", import.meta.url))) {
-    const Dictionary = await import("../dictionary/build.ts");
-    await Dictionary.build();
-  }
+async function watchMain(): Promise<void> {
+  const context = await ESBuild.context(BUILD_OPTIONS);
+  await context.watch();
+  await context.serve({ servedir: "./dist/" });
+}
+async function watchDictionary(): Promise<never> {
   const command = new Deno.Command(Deno.execPath(), {
     args: [
       "run",
@@ -32,9 +34,14 @@ if (import.meta.main) {
     stdin: "null",
   });
   const process = command.spawn();
-  const context = await ESBuild.context(BUILD_OPTIONS);
-  await context.watch();
-  await context.serve({ servedir: "./dist/" });
   const status = await process.status;
+  assert(!status.success);
   Deno.exit(status.code);
 }
+if (import.meta.main) {
+  if (!await exists(new URL("../dictionary/dictionary.ts", import.meta.url))) {
+    const Dictionary = await import("../dictionary/build.ts");
+    await Dictionary.build();
+  }
+  await Promise.all([watchDictionary(), watchMain()]);
+}