R Contribution Workflow

1. Example Contribution Workflow using the R Dev Container:

• To start working in R we will click on R:(not attach) which is in the bottom right of the VSCode window. This will open an R terminal for us.

  

  

• We can now run R commands. We will use the utils::askYesNo() function as an example

  

    > askYesNo("Is this a good example?")
    Is this a good example? (Yes/no/cancel) Yes
    [1] TRUE 

2. Editing Source Code

• Edit the source code of utils::askYesNo() to change the default options. The source code can be found in $TOP_SRCDIR/src/library/utils/R/askYesNo.R.
• You can redirect to that file using

  code $TOP_SRCDIR/src/library/utils/R/askYesNo.R
  

> Before edit:

    prompts = getOption("askYesNo", gettext(c("Yes", "No", "Cancel"))),

> With edit (for example - change to whatever you like!):

    prompts = getOption("askYesNo", gettext(c("Oh yeah!", "Don't think so", "Cancel"))),

3. Rebuild R

• We can re-build R with our changes. Since we have only modified the utils package, rebuilding R will only re-build the utils package.
• First we need to be inside $BUILDDIR.
• Quit R with q() or by closing the R terminal.
• In the bash terminal, change to the build directory:

  cd $BUILDDIR
  

• Now run the make command to rebuild R with the changes you made in step 2. This will be much faster than the full build!

  make
  

• Optionally run make check to run R's test suite with your local changes. You may skip this step while you are iterating on a bug fix or other development, until you are ready to create a patch.

• To use the re-built R, simply open a new R terminal.

4. Cross check and Re-running Code

• Check the edit has worked as expected by re-running the example code:

    > askYesNo("Is this a good example?")
    Is this a good example? (Oh yeah!/don't think so/cancel) Oh yeah!
    [1] TRUE