We actively welcome contributions to the Arrow R cookbook! If you want to make a contribution, please fork this repo and make a pull request with your changes. If you see any errors or have suggestions for recipes you'd like to see but do not know how to create, please open a GitHub issue.
If you find any typos or minor issues in the cookbook, feel free to submit a PR without opening an issue first.
The recipes are written in RMarkdown format using bookdown.
You can add new recipes to one of the existing .Rmd files, or you can create new sections by adding additional .Rmd files in the content directory. If you add a new file, you should add it to the rmd_files list in content/_bookdown.yml for it to be visible in the rendered cookbook.
After each code chunk in the recipe, you should add a test chunk that tests that the code chunk's output is as expected. Using a test chunk will allow your recipe to be tested against the latest version of arrow, and make it easier to detect if any changes made to arrow result in your recipe becoming out-of-date.
Each significant code chunk must be given a descriptive label, and be immediately followed by a unit test of its output. This test should be labelled “test_” followed by the name of the chunk that it is testing. The test chunk should also have the opts.label attribute set to “test” - this will ensure that the test is not rendered as part of the cookbook.
Here's an example of a recipe and a test:
```{r, write_parquet}
# Create table
my_table <- Table$create(tibble::tibble(group = c("A", "B", "C"), score = c(99, 97, 99)))
# Write to Parquet
write_parquet(my_table, "my_table.parquet")
```
```{r, test_write_parquet, opts.label = "test"}
test_that("write_parquet chunk works as expected", {
expect_true(file.exists("my_table.parquet"))
})
```
All recipes in the cookbook must be tested. The cookbook uses testthat to verify the recipes.
Running make rtest from the cookbook root directory will verify that the code for all of the R recipes run correctly and provide the expected output.
The Arrow R cookbook has been written using bookdown.
Running make r from the cookbook root directory (the one where the Makefile exists) will install all necessary dependencies (including the latest nightly build of the Arrow R package) and compile the cookbook to HTML.
You can see the compiled result inside the build/r directory.
If you add a new recipe to the cookbook, you do not need to commit changes to build/r to the repo, as this is automatically run by our CI when building the latest version of the cookbook on the main branch.
All participation in the Apache Arrow project is governed by the Apache Software Foundation’s code of conduct.