From dd8453401840862186f991e2d514e0d328a67987 Mon Sep 17 00:00:00 2001
From: Zhiming Guo <guo.zhming@gmail.com>
Date: Fri, 11 Sep 2020 22:53:37 +1000
Subject: [PATCH] perf(compiler): remove `createProgram` for `isolatedModules:
 true` to boost startup speed (#1941)

Since `transpile` API is used for `isolatedModules: true`, `createProgram` does not do anything with it. Therefore we can remove it
---
 src/compiler/transpiler.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/compiler/transpiler.ts b/src/compiler/transpiler.ts
index 90ea928029..fa954025fd 100644
--- a/src/compiler/transpiler.ts
+++ b/src/compiler/transpiler.ts
@@ -10,9 +10,8 @@ import type { CompilerInstance, SourceOutput } from '../types'
 export const initializeTranspilerInstance = (configs: ConfigSet, logger: Logger): CompilerInstance => {
   logger.debug('initializeTranspilerInstance(): create typescript compiler')
 
-  const { options, fileNames } = configs.parsedTsConfig
+  const { options } = configs.parsedTsConfig
   const ts = configs.compilerModule
-  const program = ts.createProgram(fileNames, options)
 
   return {
     compileFn: (code: string, fileName: string): SourceOutput => {
@@ -31,6 +30,6 @@ export const initializeTranspilerInstance = (configs: ConfigSet, logger: Logger)
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       return [result.outputText, result.sourceMapText!]
     },
-    program,
+    program: undefined,
   }
 }