From 5b883bb5d1de5a2d47d419dd0019e158b5f6896e Mon Sep 17 00:00:00 2001
From: Jimmy Lai <laijimmy0@gmail.com>
Date: Wed, 28 Jun 2023 09:08:17 +0200
Subject: [PATCH] performance: enable minification for the server bundles
 (#51831)

This PR makes the server code be minified.

## Why

This will improve performance of the server code because of the lesser
size, lesser time to parse and lesser code via tree sharking.

Cons: this should lead to increased build times, so a
`disableServerMinification` config was added


<!-- Thanks for opening a PR! Your contribution is much appreciated.
To make sure your PR is handled as smoothly as possible we request that
you follow the checklist sections below.
Choose the right checklist for the change(s) that you're making:

## For Contributors

### Improving Documentation

- Run `pnpm prettier-fix` to fix formatting issues before opening the
PR.
- Read the Docs Contribution Guide to ensure your contribution follows
the docs guidelines:
https://nextjs.org/docs/community/contribution-guide

### Adding or Updating Examples

- The "examples guidelines" are followed from our contributing doc
https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md
- Make sure the linting passes by running `pnpm build && pnpm lint`. See
https://github.com/vercel/next.js/blob/canary/contributing/repository/linting.md

### Fixing a bug

- Related issues linked using `fixes #number`
- Tests added. See:
https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs
- Errors have a helpful link attached, see
https://github.com/vercel/next.js/blob/canary/contributing.md

### Adding a feature

- Implements an existing feature request or RFC. Make sure the feature
request has been accepted for implementation before opening a PR. (A
discussion must be opened, see
https://github.com/vercel/next.js/discussions/new?category=ideas)
- Related issues/discussions are linked using `fixes #number`
- e2e tests added
(https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs
- Documentation added
- Telemetry added. In case of a feature if it's used or not.
- Errors have a helpful link attached, see
https://github.com/vercel/next.js/blob/canary/contributing.md


## For Maintainers

- Minimal description (aim for explaining to someone not on the team to
understand the PR)
- When linking to a Slack thread, you might want to share details of the
conclusion
- Link both the Linear (Fixes NEXT-xxx) and the GitHub issues
- Add review comments if necessary to explain to the reviewer the logic
behind a change

### What?

### Why?

### How?

Closes NEXT-
Fixes #

-->

link NEXT-1319
---
 packages/next/src/build/webpack-config.ts            |  7 ++++++-
 .../next/src/build/webpack/config/blocks/base.ts     |  1 +
 packages/next/src/build/webpack/config/index.ts      |  3 +++
 packages/next/src/build/webpack/config/utils.ts      |  1 +
 packages/next/src/server/config-schema.ts            |  6 ++++++
 packages/next/src/server/config-shared.ts            | 12 ++++++++++++
 6 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/packages/next/src/build/webpack-config.ts b/packages/next/src/build/webpack-config.ts
index 411f67be83785..31ed619c8b27a 100644
--- a/packages/next/src/build/webpack-config.ts
+++ b/packages/next/src/build/webpack-config.ts
@@ -1766,7 +1766,11 @@ export default async function getBaseWebpackConfig(
       runtimeChunk: isClient
         ? { name: CLIENT_STATIC_FILES_RUNTIME_WEBPACK }
         : undefined,
-      minimize: !dev && (isClient || isEdgeServer),
+      minimize:
+        !dev &&
+        (isClient ||
+          isEdgeServer ||
+          (isNodeServer && config.experimental.serverMinification)),
       minimizer: [
         // Minify JavaScript
         (compiler: webpack.Compiler) => {
@@ -2724,6 +2728,7 @@ export default async function getBaseWebpackConfig(
     experimental: config.experimental,
     disableStaticImages: config.images.disableStaticImages,
     transpilePackages: config.transpilePackages,
+    serverSourceMaps: config.experimental.serverSourceMaps,
   })
 
   // @ts-ignore Cache exists
diff --git a/packages/next/src/build/webpack/config/blocks/base.ts b/packages/next/src/build/webpack/config/blocks/base.ts
index a9b43e144b81c..ca5f1ce959f62 100644
--- a/packages/next/src/build/webpack/config/blocks/base.ts
+++ b/packages/next/src/build/webpack/config/blocks/base.ts
@@ -34,6 +34,7 @@ export const base = curry(function base(
   } else {
     if (
       ctx.isEdgeRuntime ||
+      (ctx.isServer && ctx.serverSourceMaps) ||
       // Enable browser sourcemaps:
       (ctx.productionBrowserSourceMaps && ctx.isClient)
     ) {
diff --git a/packages/next/src/build/webpack/config/index.ts b/packages/next/src/build/webpack/config/index.ts
index b9f0718469b3a..4daa1b35696a2 100644
--- a/packages/next/src/build/webpack/config/index.ts
+++ b/packages/next/src/build/webpack/config/index.ts
@@ -25,6 +25,7 @@ export async function buildConfiguration(
     transpilePackages,
     experimental,
     disableStaticImages,
+    serverSourceMaps,
   }: {
     hasAppDir: boolean
     supportedBrowsers: string[] | undefined
@@ -41,6 +42,7 @@ export async function buildConfiguration(
     future: NextConfigComplete['future']
     experimental: NextConfigComplete['experimental']
     disableStaticImages: NextConfigComplete['disableStaticImages']
+    serverSourceMaps: NextConfigComplete['experimental']['serverSourceMaps']
   }
 ): Promise<webpack.Configuration> {
   const ctx: ConfigurationContext = {
@@ -64,6 +66,7 @@ export async function buildConfiguration(
     transpilePackages,
     future,
     experimental,
+    serverSourceMaps: serverSourceMaps ?? false,
   }
 
   let fns = [base(ctx), css(ctx)]
diff --git a/packages/next/src/build/webpack/config/utils.ts b/packages/next/src/build/webpack/config/utils.ts
index 0cae76e8a83f2..004e0acac5b6d 100644
--- a/packages/next/src/build/webpack/config/utils.ts
+++ b/packages/next/src/build/webpack/config/utils.ts
@@ -22,6 +22,7 @@ export type ConfigurationContext = {
 
   sassOptions: any
   productionBrowserSourceMaps: boolean
+  serverSourceMaps: boolean
 
   transpilePackages: NextConfigComplete['transpilePackages']
 
diff --git a/packages/next/src/server/config-schema.ts b/packages/next/src/server/config-schema.ts
index b52ad11987930..1439550ee4e30 100644
--- a/packages/next/src/server/config-schema.ts
+++ b/packages/next/src/server/config-schema.ts
@@ -512,6 +512,12 @@ const configSchema = {
         logging: {
           type: 'string',
         },
+        serverMinification: {
+          type: 'boolean',
+        },
+        serverSourceMaps: {
+          type: 'boolean',
+        },
       },
       type: 'object',
     },
diff --git a/packages/next/src/server/config-shared.ts b/packages/next/src/server/config-shared.ts
index aeed79b241ef8..00b56e469a0b0 100644
--- a/packages/next/src/server/config-shared.ts
+++ b/packages/next/src/server/config-shared.ts
@@ -287,6 +287,16 @@ export interface ExperimentalConfig {
    * Allows adjusting body parser size limit for server actions.
    */
   serverActionsBodySizeLimit?: SizeLimit
+
+  /**
+   * enables the minification of server code.
+   */
+  serverMinification?: boolean
+
+  /**
+   * Enables source maps generation for the server production bundle.
+   */
+  serverSourceMaps?: boolean
 }
 
 export type ExportPathMap = {
@@ -670,6 +680,8 @@ export const defaultConfig: NextConfig = {
   output: !!process.env.NEXT_PRIVATE_STANDALONE ? 'standalone' : undefined,
   modularizeImports: undefined,
   experimental: {
+    serverMinification: false,
+    serverSourceMaps: false,
     caseSensitiveRoutes: false,
     useDeploymentId: false,
     deploymentId: undefined,