Turbopack: fix webpack loader runner layer (#91727)

mischnic · ijjk · commit 27886d3cfbec · 2026-03-20T14:30:40.000-07:00
Otherwise you get a `Dependency tracking is disabled` / infinite loop
when trying to use both turbopack.rules.loader and turbopackLoader at
the same time
diff --git a/test/development/app-dir/turbopack-import-assertions-use/app/page.tsx b/test/development/app-dir/turbopack-import-assertions-use/app/page.tsx
@@ -8,14 +8,18 @@ import replacedValue from '../data-with-placeholder.js' with { turbopackLoader:
 import rawTextViaModuleType from '../data2.txt' with { turbopackLoader: '../node_modules/test-raw-loader/index.js', turbopackModuleType: 'ecmascript' }
 // Import a non-.json file and treat it as JSON via turbopackModuleType
 import jsonData from '../data.jsonlike' with { turbopackLoader: 'test-identity-loader', turbopackModuleType: 'json' }
+// Normal rules should still work at the same time
+import jsonData2 from '../data.jsonlike2'
 
+console.log(jsonData, jsonData2)
 export default function Page() {
   return (
     <div>
       <p id="raw">{rawText}</p>
       <p id="replaced">{replacedValue}</p>
       <p id="module-type">{rawTextViaModuleType}</p>
       <p id="json-type">{jsonData.greeting}</p>
+      <p id="json-type-2">{jsonData2.greeting}</p>
     </div>
   )
 }
diff --git a/test/development/app-dir/turbopack-import-assertions-use/data.jsonlike2 b/test/development/app-dir/turbopack-import-assertions-use/data.jsonlike2
@@ -0,0 +1 @@
+{"greeting": "Hello from JSON module type 2"}
diff --git a/test/development/app-dir/turbopack-import-assertions-use/next.config.js b/test/development/app-dir/turbopack-import-assertions-use/next.config.js
@@ -1,6 +1,15 @@
 /**
  * @type {import('next').NextConfig}
  */
-const nextConfig = {}
+const nextConfig = {
+  turbopack: {
+    rules: {
+      '*.jsonlike2': {
+        loaders: ['test-identity-loader'],
+        as: '*.json',
+      },
+    },
+  },
+}
 
 module.exports = nextConfig
diff --git a/test/development/app-dir/turbopack-import-assertions-use/turbopack-import-assertions-use.test.ts b/test/development/app-dir/turbopack-import-assertions-use/turbopack-import-assertions-use.test.ts
@@ -31,4 +31,9 @@ describe('turbopack-import-assertions-use', () => {
     const $ = await next.render$('/')
     expect($('#json-type').text()).toBe('Hello from JSON module type')
   })
+
+  it('should apply identity with loader rules', async () => {
+    const $ = await next.render$('/')
+    expect($('#json-type-2').text()).toBe('Hello from JSON module type 2')
+  })
 })
diff --git a/turbopack/crates/turbopack/src/lib.rs b/turbopack/crates/turbopack/src/lib.rs
@@ -716,7 +716,7 @@ async fn process_default_internal(
             *execution_context,
             Some(import_map),
             None,
-            Layer::new(rcstr!("turbopack_use_loaders")),
+            Layer::new(rcstr!("webpack_loaders")),
             false,
         )
         .to_resolved()

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+{"greeting": "Hello from JSON module type 2"}`
Original file line number	Diff line number	Diff line change
`@@ -716,7 +716,7 @@ async fn process_default_internal(`
`716`	`716`	`*execution_context,`
`717`	`717`	`Some(import_map),`
`718`	`718`	`None,`
`719`		`- Layer::new(rcstr!("turbopack_use_loaders")),`
	`719`	`+ Layer::new(rcstr!("webpack_loaders")),`
`720`	`720`	`false,`
`721`	`721`	`)`
`722`	`722`	`.to_resolved()`