Explicit Documentation for discerning if value is supplied

[kshenk1]

Describe your use-case which is not covered by existing documentation.

If I create a Stashed file parameter named "my_file", and after choosing "Build with Parameters" the parameter params.my_file is null. This is unexpected as we're typically validating parameters by accessing them this way.

Through internal conversation I've learned that (in this particular case) my_file_FILENAME will be unset if the file is missing. It would be good to mention this in the documentation explicitly, as the build will happily continue without providing a file.

Reference any relevant documentation, other materials or issues/pull requests that can be used for inspiration.

https://plugins.jenkins.io/file-parameters/

Accessing original upload filename

Original filename will be stored in evironment in <parameter_name>_FILENAME variable - assuming parameter is named FILE, snippet below will give you file with original filename in current workspace:

node {
  unstash 'FILE'
  sh 'mv FILE $FILE_FILENAME'
}

Potentially related to: #26 as a feature.
Also related: #217

It's kinda there, but not quite...

Are you interested in contributing to the documentation?

No response

[jglick]

Yes documentation should clarify that env.XXX_FILE == null when no file is submitted, so that the job definition can decide how to proceed.

params.XXX == null is expected for stashed parameters; the value can only be accessed by unstashing. Otherwise you would use a Base64 parameter.

Also: there is a test for a GUI form submission, but it does submit a file, and is for Base64 not stashed. There is also a test for a missing file, but for a REST submission, and again for Base64. We ought to have test coverage for more scenarios, such as this case (GUI submission, missing, stashed).

[kshenk1]

Through just a little bit of testing, seems:

try {
  def my_file = "${my_file_FILENAME}"
} catch (MissingPropertyException e) {
  error("${e.message}")
}

is perhaps the best way to handle this ?

[jglick]

No need for that, simply

if (env.my_file_FILENAME == null) {
  error 'must submit a file'
}

or probably

if (!env.my_file_FILENAME) {
  error 'must submit a file'
}