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Could not report code coverage for file in sourcemap #55054
Description
Version
v22.9.0
Platform
N/A
Subsystem
test_runner
What steps will reproduce the bug?
Create index.mjs:
export {}
//# sourceMappingURL=index.mjs.mapCreate index.mjs.map:
{"version":3,"file":"index.mjs","sourceRoot":"","sources":["index.mjs"],"names":[],"mappings":"AAEA"}Run:
node --experimental-test-coverage --test index.mjsHow often does it reproduce? Is there a required condition?
Every time.
What is the expected behavior? Why is that the expected behavior?
Coverage should be reported, or an error explaining why it wasn't is displayed.
What do you see instead?
ℹ Warning: Could not report code coverage. TypeError: Cannot read properties of undefined (reading 'startOffset')
Additional information
CC @nodejs/test_runner
Activity
geeksilva97 commentedon Apr 21, 2025
It's not reproducible in 23.10.0
mcollina commentedon May 23, 2026
I investigated this from a clean
upstream/mainbuild and could not reproduce it anymore.I checked out
upstream/main, rebuiltnode, and then ran the exact repro from the issue:with:
and:
{"version":3,"file":"index.mjs","sourceRoot":"","sources":["index.mjs"],"names":[],"mappings":"AAEA"}Current behavior is a normal coverage report:
index.mjs | 100.00 | 100.00 | 100.000So this no longer fails with:
The most likely fix is #55359, which made coverage only use sourcemap remapping when
--enable-source-mapsis explicitly enabled. That matches this repro, because it only used--experimental-test-coverageand--test.There was also related hardening in #55055 for invalid or missing sourcemaps.