sundgren is a coverage diff tool, written in Rust, for understanding large and complex codebases. It runs your tests with coverage before and after a patch and reports the lines, branches, functions and test outcomes that changed. It works with any coverage tool that writes lcov, has presets for Python (pytest) and Rust (cargo-llvm-cov, cargo-tarpaulin), and comes as a VS Code extension too.
Sundgren is Swedish for "sound branch", and my mother's family name.
Install
uv tool install sundgren # or: pipx install sundgren
Linux and macOS (x86_64 and arm64). The wheels hold a self-contained binary, so running it needs no Python. Windows is not supported yet.
Docs
- Examples: a Python and a Rust project, the command and the report.
- How it works
- Reference: every option, preset key, exit code and warning.
- VS Code: the extension that plucks a test from the editor.
- Changelog
Development
One Rust crate (Rust 1.88+); Python is only the test harness and the docs build.
uv sync # dev env in .venv, with the binary built (pyright resolves imports here)
uv tool install pre-commit # once per machine
pre-commit install # once per clone: the lint hooks run on every commit, as in CI
cargo test
uv run pytest # e2e and docs tests, run the built binary
Install pre-commit as a tool, not with uvx: the git hook remembers the Python it was installed
with, and uvx runs from uv's cache, which can be cleaned.
To release, set the version in pyproject.toml and Cargo.toml, date its CHANGELOG.md
section, check with uv run tools/release.py check vX.Y.Z, and push the vX.Y.Z tag. The tag
publishes to PyPI and updates the docs site. Each pull request gets a docs preview at
https://axean.github.io/sundgren/pr-preview/pr-<N>/ until it closes, and main, with changes
not released yet, is at https://axean.github.io/sundgren/main/.
License
Apache-2.0. See LICENSE.
1 maintainer
Metadata
1 maintainer
Release files for sundgren 0.3.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | Provenance | Actions |
|---|---|---|---|---|
| sundgren-0.3.0.tar.gz | 105.7 kB | With provenance | Details for sundgren-0.3.0.tar.gz |
Built distributions (wheels)
| File | Actions Reset | |||
|---|---|---|---|---|
| sundgren-0.3.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl | Python 3 | none | Linux glibc 2.17+ x86-64 | Details for sundgren-0.3.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl |
| sundgren-0.3.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl | Python 3 | none | Linux glibc 2.17+ ARM64 | Details for sundgren-0.3.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl |
| sundgren-0.3.0-py3-none-macosx_11_0_arm64.whl | Python 3 | none | macOS 11.0+ ARM64 | Details for sundgren-0.3.0-py3-none-macosx_11_0_arm64.whl |
| sundgren-0.3.0-py3-none-macosx_10_12_x86_64.whl | Python 3 | none | macOS 10.12+ x86-64 | Details for sundgren-0.3.0-py3-none-macosx_10_12_x86_64.whl |
Total release size: 7.2 MB
Release files / sundgren-0.3.0.tar.gz
| Download URL | sundgren-0.3.0.tar.gz |
|---|---|
| Size | 105.7 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
b0d68616fdcb074f5664478485e6ce91fa81498622b0486c2b66766db4176538
|
|
BLAKE2b-256 checksum How to use checksums |
1a1df8fdb3454bfd936a653c5419d6f76d2974ea9b4067e55d02d72149c05d77
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logRelease files / sundgren-0.3.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
| Download URL | sundgren-0.3.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl |
|---|---|
| Size | 1.9 MB |
| Tags | Linux glibc 2.17+ x86-64 Python 3 |
|
SHA-256 checksum How to use checksums |
02699c3467ee5432a8781a886c46e6e1c9d075c4ac8f170f3e2d5cdc404d54a7
|
|
BLAKE2b-256 checksum How to use checksums |
cb57dc1d6903f2230f1c299545b6e62148e2696e70c5c90243261537431b4fd1
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logRelease files / sundgren-0.3.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl
| Download URL | sundgren-0.3.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl |
|---|---|
| Size | 1.8 MB |
| Tags | Linux glibc 2.17+ ARM64 Python 3 |
|
SHA-256 checksum How to use checksums |
a16b5005c28b6e334a96021ff7d52de521ab43c99791d4c9399f026f891c8fd0
|
|
BLAKE2b-256 checksum How to use checksums |
7d53f0ea65d62becd812f620847606512e2fea1dbd2214144a9ba8300b005a64
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logRelease files / sundgren-0.3.0-py3-none-macosx_11_0_arm64.whl
| Download URL | sundgren-0.3.0-py3-none-macosx_11_0_arm64.whl |
|---|---|
| Size | 1.7 MB |
| Tags | Python 3 macOS 11.0+ ARM64 |
|
SHA-256 checksum How to use checksums |
8a5e6f6af238983cf659699ac919c4ea55a98c3e5e2a9200490b1bbd6e7ccc75
|
|
BLAKE2b-256 checksum How to use checksums |
744325cfec5c443dfc2f98de04c7a28a399bdadfee583803cadec2be7f1c71ac
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logRelease files / sundgren-0.3.0-py3-none-macosx_10_12_x86_64.whl
| Download URL | sundgren-0.3.0-py3-none-macosx_10_12_x86_64.whl |
|---|---|
| Size | 1.8 MB |
| Tags | Python 3 macOS 10.12+ x86-64 |
|
SHA-256 checksum How to use checksums |
a379e7189aba58cd5a6f67d4267b8b301f43bc289ea3dfe1505befd315aabe72
|
|
BLAKE2b-256 checksum How to use checksums |
355eec8d35034a7e1fa8fd435ea9212edf1b8cfc198623a52c495816edfa7775
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logSecurity for sundgren 0.3.0
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
Full provenance
All 5 files in this release have been uploaded with provenance metadata.
Attestation for sundgren-0.3.0.tar.gz
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Oct 20, 2026.
Transparency logA note on package security
PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.
To learn more about protecting yourself from malicious actors, visit our package security documentation.
