From 3959dd8826c5c2b17d48222a907a2d40910d1287 Mon Sep 17 00:00:00 2001
From: Shu Ding <g@shud.in>
Date: Sat, 5 Nov 2022 00:08:08 +0100
Subject: [PATCH 1/2] error if the use client directive is not on the top

---
 packages/next/server/next-typescript.ts | 40 ++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/packages/next/server/next-typescript.ts b/packages/next/server/next-typescript.ts
index 3daf55ab116ca4e..c30ac7f3912466c 100644
--- a/packages/next/server/next-typescript.ts
+++ b/packages/next/server/next-typescript.ts
@@ -187,19 +187,33 @@ export function createTSPlugin(modules: {
       )
     }
 
-    function getIsClientEntry(fileName: string) {
+    function getIsClientEntry(
+      fileName: string,
+      throwOnInvalidDirective?: boolean
+    ) {
       const source = info.languageService.getProgram()?.getSourceFile(fileName)
       if (source) {
         let isClientEntry = false
         let isDirective = true
 
         ts.forEachChild(source!, (node) => {
-          if (isClientEntry || !isDirective) return
-
-          if (isDirective && ts.isExpressionStatement(node)) {
-            if (ts.isStringLiteral(node.expression)) {
-              if (node.expression.text === 'use client') {
+          if (
+            ts.isExpressionStatement(node) &&
+            ts.isStringLiteral(node.expression)
+          ) {
+            if (node.expression.text === 'use client') {
+              if (isDirective) {
                 isClientEntry = true
+              } else {
+                if (throwOnInvalidDirective) {
+                  throw {
+                    messageText:
+                      'The `"use client"` directive must be put at the top of the file.',
+                    start: node.expression.getStart(),
+                    length:
+                      node.expression.getEnd() - node.expression.getStart(),
+                  }
+                }
               }
             }
           } else {
@@ -473,7 +487,19 @@ export function createTSPlugin(modules: {
 
       const source = info.languageService.getProgram()?.getSourceFile(fileName)
       if (source) {
-        const isClientEntry = getIsClientEntry(fileName)
+        let isClientEntry = false
+
+        try {
+          isClientEntry = getIsClientEntry(fileName, true)
+        } catch (e: any) {
+          prior.push({
+            file: source,
+            category: ts.DiagnosticCategory.Error,
+            code: 71004,
+            ...e,
+          })
+          isClientEntry = false
+        }
 
         ts.forEachChild(source!, (node) => {
           if (ts.isImportDeclaration(node)) {

From 36ba7ba58c9ed69b76561e323481d50286a87fa1 Mon Sep 17 00:00:00 2001
From: Shu Ding <g@shud.in>
Date: Sat, 5 Nov 2022 20:30:27 +0100
Subject: [PATCH 2/2] fix linter

---
 packages/next/server/next-typescript.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/next/server/next-typescript.ts b/packages/next/server/next-typescript.ts
index c30ac7f3912466c..7625bc3b60bc212 100644
--- a/packages/next/server/next-typescript.ts
+++ b/packages/next/server/next-typescript.ts
@@ -206,13 +206,14 @@ export function createTSPlugin(modules: {
                 isClientEntry = true
               } else {
                 if (throwOnInvalidDirective) {
-                  throw {
+                  const e = {
                     messageText:
                       'The `"use client"` directive must be put at the top of the file.',
                     start: node.expression.getStart(),
                     length:
                       node.expression.getEnd() - node.expression.getStart(),
                   }
+                  throw e
                 }
               }
             }