[onmax]

Rollup Plugin Name: inject

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

If yes, then include "BREAKING CHANGES:" in the first commit message body, followed by a description of what is breaking.

List any relevant issue numbers:

None.

Description

When inject matches one of its keys in a module but has nothing to inject, it still returns a hires sourcemap for the unchanged code. Rollup keeps that map on the cached module, so watch mode holds one for each of these modules. A 134 KB module that only calls options.process(...) gets a map with 131,780 segments.

I hit this in a Nuxt 4 dev server. Nitro 2 runs inject over every inlined dependency, and these maps took about 1.5 GB of heap per rebuild until the server ran out of memory.

This PR returns map: null when nothing is injected, like replace does. The output sourcemap stays byte-identical. The new test fails on master and passes here.

Repro with Rollup 4.67.5 and plugin 5.0.5, plus a patched control: https://github.com/onmax/repros/tree/repro/rollup-plugin-inject-sourcemap/rollup-plugin-inject-sourcemap (pnpm install && pnpm verify)

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge.

_{Reviews (1) · Last reviewed commit: "fix(inject): return a null sourcemap whe..." · Reviewed by Greptile}