NoMethodError when PlagiabotImporter query does not return results

[ragesoss]

https://sentry2.wikiedu.org/wikiedu/p-e-dashboard/issues/2602/

NoMethodError: undefined method `each' for nil:NilClass
  lib/importers/plagiabot_importer.rb:24:in `find_recent_plagiarism'
    suspected_diffs.each do |rev|
  lib/data_cycle/constant_update.rb:62:in `update_revisions_and_articles'
    PlagiabotImporter.find_recent_plagiarism
  lib/data_cycle/constant_update.rb:37:in `run_update'
    update_revisions_and_articles
  lib/data_cycle/batch_update_logging.rb:30:in `run_update_with_pid_files'
    run_update # implemented by each update class
  lib/data_cycle/constant_update.rb:30:in `initialize'
    run_update_with_pid_files(:constant)
...
(36 additional frame(s) were not displayed)

NoMethodError: undefined method `each' for nil:NilClass

[Aeropio]

Hello I am current outreachy applicant and wants to work on this issue, please know the steps to reproduce this in my local

[Aeropio]

@ragesoss : if we check suspected_diffs.present? then this mentioned error can be avoided; incase if suspected_diffs is not present then what the method has to return?

[ragesoss]

Something like that seems reasonable, although if there's anywhere earlier in the data flow to handle this failure mode, that would be better.

A patch for this should also include a test for a mocked query that would lead to this error.

[Aeropio]

@ragesoss in api_get method of PlagiabotImporter class if we check if response is present then it would be better, but if response is not present then what the method has to return?

[Aeropio]

Something like that seems reasonable, although if there's anywhere earlier in the data flow to handle this failure mode, that would be better.

A patch for this should also include a test for a mocked query that would lead to this error.

@ragesoss where should I write the test for the mocked query? in which file?

[ragesoss]

Probably plagiabot_importer_spec.rb

[Aeropio]

@ragesoss : My understanding is that api_get method returns nil in the find_recent_plagiarism method , but i am not sure how to reproduce this error?please share the Steps to reproduce this behavior

[bwreid]

@Aeropio I think it will be easiest to just build the test so that the Net::HTTP.get returns nil. I think the problem at the moment is we're not entirely sure what yet is causing the return of nil but still want to be able to handle it.

[Aeropio]

@bwreid okay sure