fix(switchable-runtime): make dev server not break when wrong runtime config is exported

packages/next/build/analysis/get-page-static-info.ts

@@ -239,21 +239,22 @@ export async function getPageStaticInfo(params: {
     }
 
     if (
-      typeof config.runtime !== 'string' &&
-      typeof config.runtime !== 'undefined'
+      typeof config.runtime !== 'undefined' &&
+      !isServerRuntime(config.runtime)
     ) {
-      throw new Error(`Provided runtime `)
-    } else if (!isServerRuntime(config.runtime)) {
       const options = Object.values(SERVER_RUNTIME).join(', ')
       if (typeof config.runtime !== 'string') {
-        throw new Error(
+        Log.error(
           `The \`runtime\` config must be a string. Please leave it empty or choose one of: ${options}`
         )
       } else {
-        throw new Error(
+        Log.error(
           `Provided runtime "${config.runtime}" is not supported. Please leave it empty or choose one of: ${options}`
         )
       }
+      if (!isDev) {
+        process.exit(1)
+      }
     }
 
     let runtime =

packages/next/server/dev/hot-reloader.ts

@@ -602,6 +602,7 @@ export default class HotReloader {
               ? await getPageStaticInfo({
                   pageFilePath: entryData.absolutePagePath,
                   nextConfig: this.config,
+                  isDev: true,
                 })
               : {}
 

packages/next/server/dev/next-dev-server.ts

@@ -369,6 +369,7 @@ export default class DevServer extends Server {
             pageFilePath: fileName,
             nextConfig: this.nextConfig,
             page: rootFile,
+            isDev: true,
           })
 
           if (isMiddlewareFile(rootFile)) {

packages/next/server/dev/on-demand-entry-handler.ts

@@ -632,6 +632,7 @@ export function onDemandEntryHandler({
         const staticInfo = await getPageStaticInfo({
           pageFilePath: pagePathData.absolutePagePath,
           nextConfig,
+          isDev: true,
         })
 
         const added = new Map<CompilerNameValues, ReturnType<typeof addEntry>>()

test/e2e/switchable-runtime/index.test.ts

@@ -202,6 +202,74 @@ describe('Switchable runtime', () => {
           })
         }
       })
+
+      it('should not crash the dev server when invalid runtime is configured', async () => {
+        await check(
+          () => renderViaHTTP(next.url, '/invalid-runtime'),
+          /Hello from page without errors/
+        )
+
+        // Invalid runtime type
+        await next.patchFile(
+          'pages/invalid-runtime.js',
+          `
+          export default function Page() {
+            return <p>Hello from page with invalid type</p>
+          }
+
+          export const config = {
+            runtime: 10,
+          }
+            `
+        )
+        await check(
+          () => renderViaHTTP(next.url, '/invalid-runtime'),
+          /Hello from page with invalid type/
+        )
+        expect(next.cliOutput).toInclude(
+          'error - The `runtime` config must be a string. Please leave it empty or choose one of:'
+        )
+
+        // Invalid runtime
+        await next.patchFile(
+          'pages/invalid-runtime.js',
+          `
+            export default function Page() {
+              return <p>Hello from page with invalid runtime</p>
+            }
+
+            export const config = {
+              runtime: "asd"
+            }
+              `
+        )
+        await check(
+          () => renderViaHTTP(next.url, '/invalid-runtime'),
+          /Hello from page with invalid runtime/
+        )
+        expect(next.cliOutput).toInclude(
+          'error - Provided runtime "asd" is not supported. Please leave it empty or choose one of:'
+        )
+
+        // Fix the runtime
+        await next.patchFile(
+          'pages/invalid-runtime.js',
+          `
+        export default function Page() {
+          return <p>Hello from page without errors</p>
+        }
+
+        export const config = {
+          runtime: 'experimental-edge',
+        }
+
+        `
+        )
+        await check(
+          () => renderViaHTTP(next.url, '/invalid-runtime'),
+          /Hello from page without errors/
+        )
+      })
     })
   } else {
     describe('Switchable runtime (prod)', () => {

test/e2e/switchable-runtime/pages/invalid-runtime.js

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>Hello from page without errors</p>
+}