Improve launch performance by skipping wrapper script (#207)

Author: ntkme

lib/src/async-compiler.ts

@@ -6,15 +6,19 @@ import {spawn} from 'child_process';
 import {Observable} from 'rxjs';
 import {takeUntil} from 'rxjs/operators';
 
-import {compilerPath} from './compiler-path';
+import {compilerCommand} from './compiler-path';
 
 /**
  * An asynchronous wrapper for the embedded Sass compiler that exposes its stdio
  * streams as Observables.
  */
 export class AsyncEmbeddedCompiler {
   /** The underlying process that's being wrapped. */
-  private readonly process = spawn(compilerPath, {windowsHide: true});
+  private readonly process = spawn(
+    compilerCommand[0],
+    compilerCommand.slice(1),
+    {windowsHide: true}
+  );
 
   /** The child process's exit event. */
   readonly exit$ = new Promise<number | null>(resolve => {

lib/src/compiler-path.ts

@@ -6,8 +6,8 @@ import * as fs from 'fs';
 import * as p from 'path';
 import {isErrnoException} from './utils';
 
-/** The path to the embedded compiler executable. */
-export const compilerPath = (() => {
+/** The full command for the embedded compiler executable. */
+export const compilerCommand = (() => {
   // find for development
   for (const path of ['vendor', '../../../lib/src/vendor']) {
     const executable = p.resolve(
@@ -18,15 +18,33 @@ export const compilerPath = (() => {
       }`
     );
 
-    if (fs.existsSync(executable)) return executable;
+    if (fs.existsSync(executable)) return [executable];
   }
 
   try {
-    return require.resolve(
-      `sass-embedded-${process.platform}-${process.arch}/` +
-        'dart-sass-embedded/dart-sass-embedded' +
-        (process.platform === 'win32' ? '.bat' : '')
-    );
+    return [
+      require.resolve(
+        `sass-embedded-${process.platform}-${process.arch}/` +
+          'dart-sass-embedded/src/dart' +
+          (process.platform === 'win32' ? '.exe' : '')
+      ),
+      require.resolve(
+        `sass-embedded-${process.platform}-${process.arch}/` +
+          'dart-sass-embedded/src/dart-sass-embedded.snapshot'
+      ),
+    ];
+  } catch (ignored) {
+    // ignored
+  }
+
+  try {
+    return [
+      require.resolve(
+        `sass-embedded-${process.platform}-${process.arch}/` +
+          'dart-sass-embedded/dart-sass-embedded' +
+          (process.platform === 'win32' ? '.bat' : '')
+      ),
+    ];
   } catch (e: unknown) {
     if (!(isErrnoException(e) && e.code === 'MODULE_NOT_FOUND')) {
       throw e;

lib/src/sync-compiler.ts

@@ -5,15 +5,19 @@
 import {Subject} from 'rxjs';
 
 import {SyncProcess} from './sync-process';
-import {compilerPath} from './compiler-path';
+import {compilerCommand} from './compiler-path';
 
 /**
  * A synchronous wrapper for the embedded Sass compiler that exposes its stdio
  * streams as Observables.
  */
 export class SyncEmbeddedCompiler {
   /** The underlying process that's being wrapped. */
-  private readonly process = new SyncProcess(compilerPath, {windowsHide: true});
+  private readonly process = new SyncProcess(
+    compilerCommand[0],
+    compilerCommand.slice(1),
+    {windowsHide: true}
+  );
 
   /** The buffers emitted by the child process's stdout. */
   readonly stdout$ = new Subject<Buffer>();