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rgitgithooksdevtools

Pre-commit hook for devtools::document

I want to set-up a pre-commit hook for devtools::document and want to fail the commit if devtools::document changes anything. I checked the devtools::document source and it returns invisible() so it's not possible to conditionally return an exit code.

Are there any clever ways to stop the commit from happening when devtools::document does work?

Solution

  • Using the function capture.output we can catch the messages devtools::documents sends whenever it changes a file:

    Writing getScore.Rd

    So when we run:

    results <- capture.output(devtools::document())

    When a document is updated (for this example, I removed one of my .Rd files, results looks as follows:

    > results
[1] "Writing getScore.Rd"

    If nothing is written, results is empty:

    > results
character(0)

    It is easy to go on from here I think :)

    The OP, @BobJansen created the following script that runs the above method and returns a status = 0 if no files were edited, and a status = 100 if any where:

    #!/usr/bin/Rscript

source("packrat/init.R")

lines <- capture.output(devtools::document(), type = 'output')
if (length(lines) > 0) {
  print(lines)
  q(save = 'no', status = 100)
} else {
  q(save = 'no', status = 0)
}