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vdiffr

INFRA · APIS
Velocity0.0

Visual regression testing of R graphics as part of a testthat suite

github.com/r-lib/vdiffr ↗

vdiffr finished its job in 2021 and has been tracking compilers ever since.

testingsnapshotssvgtestthatr-libmaintenance
◆Current state
vdiffr generates deterministic SVG snapshots so plot changes show up as test failures. Its recent history is almost entirely toolchain: UCRT Windows compatibility twice, a revert to C++11 to work around a GCC issue, and renaming the internal SVG device so it stops colliding with svglite. The only functional additions in view are snapshot variants in 1.0.8 and a testthat fix so snapshots are no longer auto-deleted when a test errors or skips. The last release was October 2024.
◆Where it's heading
The package reached its intended shape at 1.0.0, when snapshot management moved to testthat and vdiffr shed most of its own R and JavaScript code to become a reproducible SVG engine and nothing more. There is not much left to add to that, and the release stream since reads accordingly: it moves when a compiler, an R version, or testthat moves. For a testing dependency this is a healthy end state, though it does mean the package inherits whatever the graphics engine does to snapshot stability.
◆Prediction
The entries do not support predicting a feature release. The likely next change is a compatibility fix prompted by a compiler or a testthat change, as every release since 1.0.2 has been.

◆Recent moves

  1. 1y ago

    Snapshot variants supported

    Adds support for snapshot variants, so the same plot can have different accepted snapshots per platform or R version. That is the standard escape hatch for graphics tests that legitimately differ between environments.

    View source ↗
  2. 2y ago

    Revert to C++11 for a GCC workaround

    Reverts to C++11 to work around a GCC issue. A compiler workaround with no user-visible effect.

    View source ↗
  3. 2y ago

    Rename internal SVG device to avoid svglite collision

    Renames vdiffr's internal SVG device so it can be told apart from svglite's. A naming collision between two packages that share an ancestry.

    View source ↗
  4. 4y ago

    UCRT Windows compatibility under Rtools42

    Compatibility with the UCRT build of Windows under Rtools42, one day after the same fix for UCRT generally. Toolchain follow-up.

    View source ↗
  5. 4y ago

    UCRT Windows compatibility

    Compatibility with the UCRT build of Windows, contributed externally. Build-level change only.

    View source ↗
  6. 5y ago

    Snapshots survive errored and skipped tests

    Stops testthat auto-deleting snapshot files that were not regenerated because a test errored or skipped. Without this, one unrelated failure could silently wipe accepted snapshots and turn a red test run into a much larger cleanup.

    View source ↗