chore: ssr.format

vitejs · May 28, 2022 · 773f234 · 773f234
1 parent ad9f17e
commit 773f234
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Showing 8 changed files with 28 additions and 10 deletions.
diff --git a/docs/config/ssr-options.md b/docs/config/ssr-options.md
@@ -20,7 +20,15 @@ Prevent listed dependencies from being externalized for SSR. If `true`, no depen
 
 ## ssr.target
 
-- **Type:** `'node' | 'webworker' | 'node-cjs'`
+- **Type:** `'node' | 'webworker'`
 - **Default:** `node`
 
 Build target for the SSR server.
+
+## ssr.format
+
+- **Type:** `'esm' | 'cjs'`
+- **Default:** `esm`
+- **Experimental**
+
+Build format for the SSR server. Since Vite v3 the SSR build generates ESM by default. `'cjs'` can be selected to generate a CJS build, but it isn't recommended. The option is left marked as experimental to give users more time to update to ESM. CJS builds requires complex externalization heuristics that aren't present in the ESM format.
diff --git a/docs/vite.config.ts b/docs/vite.config.ts
@@ -2,6 +2,6 @@ import { defineConfig } from 'vite'
 
 export default defineConfig({
   ssr: {
-    target: 'node-cjs'
+    format: 'cjs'
   }
 })
diff --git a/packages/vite/src/node/build.ts b/packages/vite/src/node/build.ts
@@ -382,7 +382,7 @@ async function doBuild(
   // In CJS, we can pass the externals to rollup as is. In ESM, we need to
   // do it in the resolve plugin so we can add the resolved extension for
   // deep node_modules imports
-  if (ssr && config.ssr?.target === 'node-cjs') {
+  if (ssr && config.ssr?.format === 'cjs') {
     external = await cjsSsrResolveExternal(config, userExternal)
   }
 
@@ -421,7 +421,7 @@ async function doBuild(
 
   try {
     const buildOutputOptions = (output: OutputOptions = {}): OutputOptions => {
-      const cjsSsrBuild = ssr && config.ssr?.target === 'node-cjs'
+      const cjsSsrBuild = ssr && config.ssr?.format === 'cjs'
       return {
         dir: outDir,
         // Default format is 'es' for regular and for SSR builds

diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
@@ -228,7 +228,9 @@ export interface ExperimentalOptions {
   importGlobRestoreExtension?: boolean
 }
 
-export type SSRTarget = 'node' | 'webworker' | 'node-cjs'
+export type SSRTarget = 'node' | 'webworker'
+
+export type SSRFormat = 'esm' | 'cjs'
 
 export interface SSROptions {
   external?: string[]
@@ -239,6 +241,14 @@ export interface SSROptions {
    * Default: 'node'
    */
   target?: SSRTarget
+  /**
+   * Define the format for the ssr build. Since Vite v3 the SSR build generates ESM by default.
+   * `'cjs'` can be selected to generate a CJS build, but it isn't recommended. This option is
+   * left marked as experimental to give users more time to update to ESM. CJS builds requires
+   * complex externalization heuristics that aren't present in the ESM format.
+   * @experimental
+   */
+  format?: SSRFormat
 }
 
 export interface ResolveWorkerOptions {

diff --git a/packages/vite/src/node/plugins/importAnalysis.ts b/packages/vite/src/node/plugins/importAnalysis.ts
@@ -362,7 +362,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
           }
           // skip ssr external
           if (ssr) {
-            if (config.ssr?.target === 'node-cjs') {
+            if (config.ssr?.format === 'cjs') {
               if (cjsShouldExternalizeForSSR(specifier, server._ssrExternals)) {
                 continue
               }

diff --git a/packages/vite/src/node/plugins/index.ts b/packages/vite/src/node/plugins/index.ts
@@ -64,7 +64,7 @@ export async function resolvePlugins(
       asSrc: true,
       getDepsOptimizer: () => getDepsOptimizer(config),
       shouldExternalize:
-        isBuild && config.build.ssr && config.ssr?.target !== 'node-cjs'
+        isBuild && config.build.ssr && config.ssr?.format !== 'cjs'
           ? (id) => shouldExternalizeForSSR(id, config)
           : undefined
     }),

diff --git a/packages/vite/src/node/plugins/ssrRequireHook.ts b/packages/vite/src/node/plugins/ssrRequireHook.ts
@@ -15,7 +15,7 @@ export function ssrRequireHookPlugin(config: ResolvedConfig): Plugin | null {
     !config.build.ssr ||
     !config.resolve.dedupe?.length ||
     config.ssr?.noExternal === true ||
-    config.ssr?.target !== 'node-cjs' ||
+    config.ssr?.format !== 'cjs' ||
     isBuildOutputEsm(config)
   ) {
     return null

diff --git a/packages/vite/src/node/ssr/ssrExternal.ts b/packages/vite/src/node/ssr/ssrExternal.ts
@@ -177,8 +177,8 @@ function createIsSsrExternal(
   }
 }
 
-// When ssr.format is 'node-cjs', this function is used reverting to the Vite 2.9 era
-// SSR externalize heuristics
+// When ssr.format is 'cjs', this function is used reverting to the Vite 2.9
+// SSR externalization heuristics
 function cjsSsrCollectExternals(
   root: string,
   preserveSymlinks: boolean | undefined,