From afe7c8ecd8f2d5b80c31e9791346ab1bcde03c7e Mon Sep 17 00:00:00 2001
From: martinfrancois <f.martin@fastmail.com>
Date: Sat, 8 Aug 2026 02:45:34 +0200
Subject: [PATCH] Remove unused `hasWarnings` and `warnings`

Nothing reads these two fields on `TypeCheckResult`.

`verifyAndRunTypeScript` has four callers:

- `build/type-check.ts` reads only `inputFilesCount`, `totalFilesCount` and
  `incremental`
- `next-test` reads only `version`
- `setup-dev-bundler` reads only `version`
- `next-typegen` throws the result away

`warnings` is also always empty. It looks for diagnostics with the category
`Warning`, but I checked, TypeScript 6.0.2 has no messages in that category.
Deprecation messages use `Suggestion` instead.

So on every build we filtered and formatted every diagnostic to build a list
that was always empty, and that nobody read.
---
 packages/next/src/lib/typescript/runTypeCheck.ts    | 11 -----------
 packages/next/src/lib/typescript/runTypeCheckCli.ts |  1 -
 2 files changed, 12 deletions(-)

diff --git a/packages/next/src/lib/typescript/runTypeCheck.ts b/packages/next/src/lib/typescript/runTypeCheck.ts
index 56462a875037..9d97f59146fc 100644
--- a/packages/next/src/lib/typescript/runTypeCheck.ts
+++ b/packages/next/src/lib/typescript/runTypeCheck.ts
@@ -8,8 +8,6 @@ import { CompileError } from '../compile-error'
 import { warn } from '../../build/output/log'
 
 export interface TypeCheckResult {
-  hasWarnings: boolean
-  warnings?: string[]
   inputFilesCount?: number
   totalFilesCount?: number
   incremental: boolean
@@ -108,7 +106,6 @@ export async function runTypeCheck(
 
   if (fileNames.length < 1) {
     return {
-      hasWarnings: false,
       inputFilesCount: 0,
       totalFilesCount: 0,
       incremental: false,
@@ -214,15 +211,7 @@ export async function runTypeCheck(
     )
   }
 
-  const warnings = allDiagnostics
-    .filter((d) => d.category === typescript.DiagnosticCategory.Warning)
-    .map((d) =>
-      getFormattedDiagnostic(typescript, baseDir, distDir, d, isAppDirEnabled)
-    )
-
   return {
-    hasWarnings: true,
-    warnings,
     inputFilesCount: fileNames.length,
     totalFilesCount: program.getSourceFiles().length,
     incremental,
diff --git a/packages/next/src/lib/typescript/runTypeCheckCli.ts b/packages/next/src/lib/typescript/runTypeCheckCli.ts
index 75258d3369f6..1abdb7f37685 100644
--- a/packages/next/src/lib/typescript/runTypeCheckCli.ts
+++ b/packages/next/src/lib/typescript/runTypeCheckCli.ts
@@ -59,7 +59,6 @@ export async function runTypeCheckCli({
   }
 
   return {
-    hasWarnings: false,
     incremental,
   }
 }