From 4261fdf5d367df9e39ce99967718248dbd3960b4 Mon Sep 17 00:00:00 2001
From: Zack Jackson <25274700+ScriptedAlchemy@users.noreply.github.com>
Date: Tue, 21 Jul 2026 21:10:07 +0000
Subject: [PATCH 1/3] fix: preserve in-memory dev output

---
 .changeset/quiet-disks-rest.md | 5 +++++
 src/index.ts                   | 1 -
 tests/features.test.ts         | 2 +-
 tests/index.test.ts            | 2 +-
 4 files changed, 7 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/quiet-disks-rest.md

diff --git a/.changeset/quiet-disks-rest.md b/.changeset/quiet-disks-rest.md
new file mode 100644
index 00000000..3f881289
--- /dev/null
+++ b/.changeset/quiet-disks-rest.md
@@ -0,0 +1,5 @@
+---
+'rsbuild-plugin-react-router': patch
+---
+
+Stop forcing development output to disk so `dev.writeToDisk: false` and Rsbuild's in-memory default are preserved.
diff --git a/src/index.ts b/src/index.ts
index 7144c910..f7abb10b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -800,7 +800,6 @@ export const pluginReactRouter = (
           assetPrefix: config.output?.assetPrefix || '/',
         },
         dev: {
-          writeToDisk: true,
           ...lazyCompilation,
           watchFiles: mergeWatchFiles(config.dev?.watchFiles, routeWatchFiles),
         },
diff --git a/tests/features.test.ts b/tests/features.test.ts
index 6e1489f2..28b505cf 100644
--- a/tests/features.test.ts
+++ b/tests/features.test.ts
@@ -33,7 +33,7 @@ describe('pluginReactRouter', () => {
       // The plugin should not override Rsbuild's HMR defaults.
       expect(config.dev.hmr).toBe(true);
       expect(config.dev.liveReload).toBe(true);
-      expect(config.dev.writeToDisk).toBe(true);
+      expect(config.dev.writeToDisk).toBe(false);
     });
 
     it('should register the dev server middleware via server.setup', async () => {
diff --git a/tests/index.test.ts b/tests/index.test.ts
index 617e1683..a58e9a63 100644
--- a/tests/index.test.ts
+++ b/tests/index.test.ts
@@ -60,7 +60,7 @@ describe('pluginReactRouter', () => {
     // The plugin should not override Rsbuild's HMR defaults.
     expect(config.dev.hmr).toBe(true);
     expect(config.dev.liveReload).toBe(true);
-    expect(config.dev.writeToDisk).toBe(true);
+    expect(config.dev.writeToDisk).toBe(false);
     expect(config.dev.lazyCompilation).toMatchObject({
       entries: true,
       imports: true,

From 940cf7fea07f534f00b364b7d83718a79043ec3a Mon Sep 17 00:00:00 2001
From: Zack Jackson <25274700+ScriptedAlchemy@users.noreply.github.com>
Date: Tue, 21 Jul 2026 21:15:22 +0000
Subject: [PATCH 2/3] test: allow in-memory route additions

---
 examples/default-template/tests/e2e/dev-route-watch.test.ts | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/examples/default-template/tests/e2e/dev-route-watch.test.ts b/examples/default-template/tests/e2e/dev-route-watch.test.ts
index 56dceef2..cc0e3ed2 100644
--- a/examples/default-template/tests/e2e/dev-route-watch.test.ts
+++ b/examples/default-template/tests/e2e/dev-route-watch.test.ts
@@ -144,7 +144,6 @@ test.describe('dev route watch', () => {
   }) => {
     await page.goto('/');
     await expect(page.locator('h1')).toContainText('Welcome to React Router');
-    const restartMarkerBeforeAdd = readRestartMarkerVersion();
 
     writeFileSync(
       addedRoutePath,
@@ -161,9 +160,6 @@ test.describe('dev route watch', () => {
     await page.goto(addedRouteUrl);
     await expect(page.locator('h1')).toHaveText(addedRouteText);
 
-    await expect
-      .poll(readRestartMarkerVersion, { timeout: 10000 })
-      .not.toBe(restartMarkerBeforeAdd);
     const restartMarkerBefore = readRestartMarkerVersion();
     writeFileSync(
       addedRoutePath,

From 4ae805349bbf097cb42eeacc9bf23cea2edc903a Mon Sep 17 00:00:00 2001
From: Zack Jackson <25274700+ScriptedAlchemy@users.noreply.github.com>
Date: Tue, 21 Jul 2026 21:22:58 +0000
Subject: [PATCH 3/3] test: preserve writeToDisk overrides

---
 tests/index.test.ts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/index.test.ts b/tests/index.test.ts
index a58e9a63..8452bebd 100644
--- a/tests/index.test.ts
+++ b/tests/index.test.ts
@@ -72,6 +72,19 @@ describe('pluginReactRouter', () => {
     ).toBe(false);
   });
 
+  it('preserves an explicit writeToDisk override', async () => {
+    const rsbuild = await createStubRsbuild({
+      rsbuildConfig: {
+        dev: { writeToDisk: true },
+      },
+    });
+
+    rsbuild.addPlugins([pluginReactRouter()]);
+    const config = await rsbuild.unwrapConfig();
+
+    expect(config.dev.writeToDisk).toBe(true);
+  });
+
   it('adds the committed custom-server build entry only in development', async () => {
     const devRsbuild = await createStubRsbuild({ rsbuildConfig: {} });
     devRsbuild.addPlugins([pluginReactRouter({ customServer: true })]);