[Aejkatappaja]

Depends on #9153. This branch is stacked on it, so the first two commits are #9153's; only the last one is new here. I'll rebase once #9153 lands.

What is it?

• Bug

Description

With qwikDevtools() enabled, every module served in dev loses its source map. The plugin's pre transform returned { code, map: { mappings: '' } } for every file it saw, including the ones it doesn't touch, and Vite chains that empty map into the final one. Breakpoints in the original source stop working and browser stack traces point at the compiled output.

Measured with server.transformRequest('/src/routes/layout.tsx') on a Router SSR app:

	mappings length	sources
without DevTools	152	["layout.tsx"]
with DevTools, before	0	undefined
with DevTools, after	152	["layout.tsx"]

The transform now returns null when it doesn't change the file, and map: null when it instruments it. A null map tells Vite the positions didn't change, which holds since #9153 keeps every line where it was. MCP's transform and DevTools' own statistics plugin already do the same.

One limit: on lines that get an injection (the component's opening line, line 1 for the imports, a hook's line) the columns are still shifted, and the browser's source view shows the instrumented code rather than the original, since the optimizer builds sourcesContent from what it receives. Lines are right everywhere.

Test: a Vite server running only the DevTools plugin checks that an untouched .ts file and an instrumented .tsx component both keep sources and non-empty mappings. It fails on main.

Checklist

• My code follows the developer guidelines of this project
• I performed a self-review of my own code
• I added a changeset with pnpm change
• I added new tests to cover the fix / functionality

[changeset-bot]

🦋 Changeset detected

Latest commit: f53ca40

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
@qwik.dev/devtools	Patch
create-qwik	Patch
eslint-plugin-qwik	Patch
@qwik.dev/mcp	Patch
@qwik.dev/react	Patch
@qwik.dev/router	Patch
@qwik.dev/utils	Patch
@qwik.dev/core	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

Open in StackBlitz

@qwik.dev/core

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/core@9155

@qwik.dev/router

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/router@9155

@qwik.dev/utils

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/utils@9155

eslint-plugin-qwik

npm i https://pkg.pr.new/QwikDev/qwik/eslint-plugin-qwik@9155

create-qwik

npm i https://pkg.pr.new/QwikDev/qwik/create-qwik@9155

@qwik.dev/optimizer

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/optimizer@9155

@qwik.dev/devtools

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/devtools@9155

@qwik.dev/mcp

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/mcp@9155

commit: f53ca40

[Varixo]

lgtm