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vdiffr

Visual regression testing and graphical diffing with testthat

https://github.com/r-lib/vdiffr

Science Score: 23.0%

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    1 of 20 committers (5.0%) from academic institutions
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    Low similarity (12.6%) to scientific vocabulary

Keywords

ggplot2 graphics testthat

Keywords from Contributors

tidy-data visualisation grammar data-manipulation geos csv gdal setup fwf parsing
Last synced: 6 months ago · JSON representation

Repository

Visual regression testing and graphical diffing with testthat

Basic Info
  • Host: GitHub
  • Owner: r-lib
  • License: other
  • Language: C++
  • Default Branch: main
  • Homepage: https://vdiffr.r-lib.org
  • Size: 2.81 MB
Statistics
  • Stars: 192
  • Watchers: 5
  • Forks: 31
  • Open Issues: 9
  • Releases: 18
Topics
ggplot2 graphics testthat
Created almost 10 years ago · Last pushed over 1 year ago
Metadata Files
Readme Changelog License Code of conduct

README.md

vdiffr

CRAN status R-CMD-check Codecov test coverage <!-- badges: end -->

vdiffr is a testthat extension for monitoring the appearance of R plots. It generates reproducible SVG files and registers them as testthat snapshots.

How to use vdiffr

1) Add graphical expectations by including expect_doppelganger() in your test files.

1) Run devtools::test().

1) If test() detected new snapshots or changes to existing snapshots, run testthat::snapshot_review() to review them.

There may be many reasons for a snapshot to fail. Upstream changes (e.g. to the R graphics engine or to ggplot2) may cause subtle differences in your plots that are not actual failures. For this reason, snapshots do not cause failures on CRAN by default. You will only see failures locally or on CI platforms such as Github Actions.

Adding expectations

vdiffr integrates with testthat through the expect_doppelganger() expectation. It takes as arguments:

  • A title. This title is used in two ways. First, the title is standardised (it is converted to lowercase and any character that is not alphanumeric or a space is turned into a dash) and used as filename for storing the figure. Secondly, with ggplot2 figures the title is automatically added to the plot with ggtitle() (only if no ggtitle has been set).

  • A figure. This can be a ggplot object, a recorded plot, a function to be called, or more generally any object with a print method.

The snapshots are recorded in subfolders of the _snaps/ directory.

```r disphistbase <- function() hist(mtcars$disp) disphistggplot <- ggplot(mtcars, aes(disp)) + geom_histogram()

vdiffr::expectdoppelganger("Base graphics histogram", disphistbase) vdiffr::expectdoppelganger("ggplot2 histogram", disphistggplot) ```

Note that in addition to automatic ggtitles, ggplot2 figures are assigned the minimalistic theme theme_test() (unless they already have been assigned a theme).

Debugging

It is sometimes difficult to understand the cause of a doppelganger failure. A frequent cause of failure is undeterministic generation of plots. Potential culprits are:

  • Some of the plot components depend on random variation. Try setting a seed, for instance with withr::local_seed().

  • The plot depends on some system library. For instance sf plots depend on libraries like GEOS and GDAL. It might not be possible to test these plots with vdiffr (which can still be used for manual inspection, add a [testthat::skip()] before the expect_doppelganger() call in that case).

To help you understand the causes of a failure, vdiffr automatically logs the SVG diff of all failures when run under R CMD check. The log is located in tests/vdiffr.Rout.fail and should be displayed in your CI logs.

You can also set the VDIFFR_LOG_PATH environment variable with Sys.setenv() to unconditionally (also interactively) log failures in the file pointed by the variable.

Skipping all vdiffr checks on some platforms

See ggplot2's approach which wraps expect_doppelganger() with a version that that calls testthat::skip() on the relevant platforms (as determined by environment variables): https://github.com/tidyverse/ggplot2/blob/ddd207e926cc1c1847dc661d9a099b8ec19c4010/tests/testthat/helper-vdiffr.R#L1-L15.

Building vdiffr

This section is only relevant for building vdiffr from scratch, as opposed to installing from a pre-built package on CRAN.

Building vdiffr requires the system dependency libpng. As vdiffr doesn't have any build-time configuration, your R configuration must point to libpng's include and lib folders.

For instance on macOS, install libpng with:

sh brew install libpng

And make sure your ~/.R/Makevars knows about Homebrew's include and lib folders where libpng should now be installed. On arm64 hardware, this would be:

mk CPPFLAGS += -I/opt/homebrew/include LDFLAGS += -L/opt/homebrew/lib

Owner

  • Name: R infrastructure
  • Login: r-lib
  • Kind: organization

GitHub Events

Total
  • Create event: 2
  • Release event: 1
  • Issues event: 18
  • Watch event: 8
  • Delete event: 3
  • Issue comment event: 14
  • Push event: 29
  • Pull request event: 5
Last Year
  • Create event: 2
  • Release event: 1
  • Issues event: 18
  • Watch event: 8
  • Delete event: 3
  • Issue comment event: 14
  • Push event: 29
  • Pull request event: 5

Committers

Last synced: 9 months ago

All Time
  • Total Commits: 394
  • Total Committers: 20
  • Avg Commits per committer: 19.7
  • Development Distribution Score (DDS): 0.091
Past Year
  • Commits: 21
  • Committers: 3
  • Avg Commits per committer: 7.0
  • Development Distribution Score (DDS): 0.095
Top Committers
Name Email Commits
Lionel Henry l****y@g****m 358
Thomas Lin Pedersen t****5@g****m 6
Nate n****y@g****m 5
Carson Sievert c****1@g****m 3
Dana Seidel d****l@b****u 2
Hiroaki Yutani y****i@g****m 2
Jeroen Ooms j****s@g****m 2
KZARCA k****a@g****m 2
Mara Averick m****k@g****m 2
Maëlle Salmon m****n@y****e 2
Christophe Dervieux c****x@g****m 1
Dewey Dunnington d****y@f****t 1
Evgeni Chasnovski e****i@g****m 1
Gordon Shotwell g****l@g****m 1
Greg Lin g****n@r****m 1
Gregory R. Warnes g****s@m****m 1
Ilari Scheinin i****n@g****m 1
Kara Woo k****o 1
Michael Chirico m****4@g****m 1
maksymis 3****s 1
Committer Domains (Top 20 + Academic)
mdsol.com: 1 rstudio.com: 1 fishandwhistle.net: 1 berkeley.edu: 1

Issues and Pull Requests

Last synced: 6 months ago

All Time
  • Total issues: 84
  • Total pull requests: 36
  • Average time to close issues: about 1 year
  • Average time to close pull requests: 7 months
  • Total issue authors: 48
  • Total pull request authors: 19
  • Average comments per issue: 2.92
  • Average comments per pull request: 1.33
  • Merged pull requests: 28
  • Bot issues: 0
  • Bot pull requests: 0
Past Year
  • Issues: 4
  • Pull requests: 3
  • Average time to close issues: about 2 months
  • Average time to close pull requests: 1 day
  • Issue authors: 4
  • Pull request authors: 1
  • Average comments per issue: 0.25
  • Average comments per pull request: 0.33
  • Merged pull requests: 3
  • Bot issues: 0
  • Bot pull requests: 0
View more stats
Top Authors
Issue Authors
  • hadley (11)
  • lionel- (8)
  • IndrajeetPatil (4)
  • njtierney (4)
  • yutannihilation (4)
  • thomasp85 (3)
  • gavinsimpson (3)
  • jtlandis (2)
  • r2evans (2)
  • pat-s (2)
  • echasnovski (2)
  • clauswilke (2)
  • jgabry (2)
  • gustavdelius (1)
  • krlmlr (1)
Pull Request Authors
  • lionel- (11)
  • thomasp85 (4)
  • yutannihilation (2)
  • nathancday (2)
  • maksymiuks (2)
  • maelle (2)
  • batpigandme (1)
  • jimhester (1)
  • ilarischeinin (1)
  • pmur002 (1)
  • GShotwell (1)
  • paleolimbot (1)
  • cpsievert (1)
  • cderv (1)
  • echasnovski (1)
Top Labels
Issue Labels
feature (12) GUI :star: (7) tidy-dev-day :nerd_face: (6) backend :wrench: (5) bug (3) testthat :ballot_box_with_check: (2) documentation (2) upkeep (1)
Pull Request Labels
tidy-dev-day :nerd_face: (2)

Packages

  • Total packages: 2
  • Total downloads:
    • cran 83,747 last-month
  • Total docker downloads: 150,388
  • Total dependent packages: 284
    (may contain duplicates)
  • Total dependent repositories: 610
    (may contain duplicates)
  • Total versions: 28
  • Total maintainers: 1
cran.r-project.org: vdiffr

Visual Regression Testing and Graphical Diffing

  • Versions: 19
  • Dependent Packages: 284
  • Dependent Repositories: 609
  • Downloads: 83,747 Last month
  • Docker Downloads: 150,388
Rankings
Dependent packages count: 0.5%
Dependent repos count: 0.6%
Average: 1.8%
Downloads: 2.2%
Docker downloads count: 2.3%
Stargazers count: 2.4%
Forks count: 2.8%
Maintainers (1)
lionel@posit.co
Last synced: 6 months ago
conda-forge.org: r-vdiffr
  • Versions: 9
  • Dependent Packages: 0
  • Dependent Repositories: 1
Rankings
Dependent repos count: 24.3%
Stargazers count: 28.0%
Forks count: 31.9%
Average: 34.0%
Dependent packages count: 51.6%
Last synced: 6 months ago

Dependencies

DESCRIPTION cran
  • R >= 3.2.0 depends
  • diffobj * imports
  • glue * imports
  • grDevices * imports
  • htmltools * imports
  • lifecycle * imports
  • rlang * imports
  • testthat >= 3.0.3 imports
  • xml2 >= 1.0.0 imports
  • covr * suggests
  • ggplot2 >= 3.2.0 suggests
  • roxygen2 * suggests
  • withr * suggests
tests/testthat/mock-pkg/DESCRIPTION cran
  • testthat * suggests
  • vdiffr * suggests
.github/workflows/R-CMD-check.yaml actions
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.github/workflows/test-coverage.yaml actions
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  • r-lib/actions/setup-r-dependencies v2 composite