start adding visual unit tests

[tjmahr]

Use the vdiffr package.

Set up a few tests.

• add new testing infrastructure to package
• write minimal internal documentation.

Add tests for a few functions to practice how it works.

• mcmc_intervals()
• mcmc_areas()
• mcmc_areas_ridges()
• mcmc_rhat()
• mcmc_rhat_hist()
• mcmc_neff()
• mcmc_neff_hist()

[tjmahr]

Some notes.

• Reference images are stored in tests/figs/[testthat context].
• vdiffr::expect_doppelganger("title for test plot", plot) compares the plot with the one saved in the collection of reference images. The test is skipped when there is no reference image.
• vdiffr::collect_cases() will run through the tests and create new reference images.
• vdiffr::manage_cases() opens a shiny app so you can see visual diffs of plots or confirm new reference images.

• Clicking "validate" will confirm the changes to a plot and update the reference version.
• There is a file called test/figs/deps.txt that stores dependency versions. Tests will be skipped when there is a version difference in the testing computer and the deps file. (Because I program on Windows mostly, I might have to be more careful about getting my dependencies to match the typical ones in e.g. travis.)

[jgabry]

This is cool. I had seen mention of vdiffr but I’ve never played around with it. Testing the plots themselves is something that I’ve wanted to do though, so I’m definitely in favor of using this.

…

On Fri, Nov 17, 2017 at 9:50 AM TJ Mahr ***@***.***> wrote: Some notes. - Reference images are stored in tests/figs/[testthat context]. - vdiffr::expect_doppelganger("plot title", plot) to compare the plot with the one saved in the collection of reference images. The test is skipped when there is no reference image. - vdiffr::collect_cases() will run through the tests and create new reference images. - vdiffr::manage_cases() opens a shiny app so you can see visual diffs of plots [image: image] <https://user-images.githubusercontent.com/1890315/32952851-0e820834-cb74-11e7-93b1-3450dcc7b0eb.png> - Clicking "validate" will confirm the changes to a plot and update the reference version. - There is a file called test/figs/deps.txt that stores dependency versions. Tests will be skipped when there is a version difference in the testing computer and the deps file. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#124 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AHb4Q2v7a07AIHrLKWR-AaCcBtLzt5rPks5s3Z09gaJpZM4QiGm0> .