From 312da96d9a315f5dc50c9648fb3488ef2907b44a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <mbombeck@gmail.com>
Date: Wed, 9 Sep 2026 19:03:38 +0200
Subject: [PATCH] build: type-check the application program, not the test tree,
 in next build
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next 16.3 type-checks the whole tsconfig program during the build. That
reaches the unit tests under src/**/__tests__, their fixtures under
tests/, the Playwright config and the e2e tree, none of which is in the
image build context — .dockerignore leaves tests/ and e2e/ out on
purpose — so the image build stopped at "Cannot find module
'../../tests/fixtures/...'" on both architectures.

The build now reads tsconfig.build.json, which extends the main tsconfig
and excludes the test tree and the test-runner configs. `pnpm typecheck`
keeps using tsconfig.json and still covers the full program; the change
narrows only what `next build` compiles, which was already the case on
16.2 by omission. Verified by building with tests/ and e2e/ moved away.
---
 next.config.ts      |  6 ++++++
 tsconfig.build.json | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 tsconfig.build.json

diff --git a/next.config.ts b/next.config.ts
index 3ea427424..3e3a554fa 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -5,6 +5,12 @@ import { version as PKG_VERSION } from "./package.json";
 
 const nextConfig: NextConfig = {
   output: "standalone",
+  // `next build` type-checks the whole tsconfig program since 16.3, which
+  // reaches the unit tests under `src/**/__tests__` and their fixtures under
+  // `tests/`. The image build context leaves `tests/` and `e2e/` out on
+  // purpose, so the build reads a tsconfig without them; `pnpm typecheck`
+  // still covers the full program.
+  typescript: { tsconfigPath: "tsconfig.build.json" },
   poweredByHeader: false,
   // v1.4.38.4 — expose the package.json version to the client bundle
   // so the `<VersionPoller>` can compare the shell-baked version
diff --git a/tsconfig.build.json b/tsconfig.build.json
new file mode 100644
index 000000000..88451f908
--- /dev/null
+++ b/tsconfig.build.json
@@ -0,0 +1,17 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": [
+    "node_modules",
+    "scripts",
+    "tests",
+    "e2e",
+    "src/**/__tests__/**",
+    "src/**/*.test.ts",
+    "src/**/*.test.tsx",
+    "playwright.config.ts",
+    "vitest.config.ts",
+    "vitest.config.mts",
+    "vitest.integration.config.ts",
+    "vitest.integration.config.mts"
+  ]
+}