fix: Allow enabling esbuild.minifyWhitespace for es format in lib mode (

fix vitejs#6555)

To produce es bundles that can be tree-shaken, lib mode disables
minifyWhitespace by default when using the es format. But there are
cases where we want an es bundle that is as small as possible and that
does not need to be tree-shakable. This change allows minifyWhitespace
to be re-enabled if the user so desires.

docs/config/build-options.md

@@ -230,7 +230,7 @@ During the SSR build, static assets aren't emitted as it is assumed they would b
 
 Set to `false` to disable minification, or specify the minifier to use. The default is [esbuild](https://github.com/evanw/esbuild) which is 20 ~ 40x faster than terser and only 1 ~ 2% worse compression. [Benchmarks](https://github.com/privatenumber/minification-benchmarks)
 
-Note the `build.minify` option does not minify whitespaces when using the `'es'` format in lib mode, as it removes pure annotations and breaks tree-shaking.
+Note the `build.minify` option does not minify whitespaces when using the `'es'` format in lib mode, as it removes pure annotations and breaks tree-shaking. To force whitespace minification for `'es'` format in lib mode, explicitly set `esbuild.minifyWhitespace` to `true`.
 
 Terser must be installed when it is set to `'terser'`.
 

packages/vite/src/node/__tests__/plugins/esbuild.spec.ts

@@ -201,7 +201,7 @@ describe('resolveEsbuildTranspileOptions', () => {
       minify: false,
       minifyIdentifiers: true,
       minifySyntax: true,
-      minifyWhitespace: false,
+      minifyWhitespace: true,
       treeShaking: true,
       supported: {
         'dynamic-import': true,

packages/vite/src/node/plugins/esbuild.ts

@@ -426,7 +426,7 @@ export function resolveEsbuildTranspileOptions(
         minify: false,
         minifyIdentifiers: options.minifyIdentifiers ?? true,
         minifySyntax: options.minifySyntax ?? true,
-        minifyWhitespace: false,
+        minifyWhitespace: options.minifyWhitespace ?? false,
         treeShaking: true,
       }
     } else {