Allow a Job to run if it passes a script - github-actions

Question

I would like to allow a job to run only if its name can be found in some file.
jobs:
job1:
if : run some script that returns true if "${{ github.job }}" is in file.txt
steps:
...
However I'm quite sure i cant run a script outside of run, which I believe can't appear before the steps section, right?
If the option above simply isn't possible, perhaps there is a way to run this script on the first step and have the next steps not run unless the said critical step passed?
Thanks!

Answer 1

You could for example use 2 jobs in your action, where the second job would only be executed if the first one succeed return true using an if condition and outputs.
The workflow would look like something as below:
jobs:
job1:
runs-on: ubuntu-latest
outputs:
output1: ${{ steps.script.outputs.bool }}
steps:
- name: Run the python script
id: script
run: |
value=$((your command running the script here) 2> &1) # should return true
echo "::set-output name=bool::$value" # set the value as output
job2:
runs-on: ubuntu-latest
# Wait from the job1 to be completed before starting job2
needs: job1
if ${{ ${{needs.job1.outputs.output1}} == true }} # won't execute if output of job 1 isn't true
steps:
...
If you want to know more about:
if condition + context and expression
outputs
Note: The contains expression in the if condition could also be used eventually depending on your context (what the script does). It could even be the easiest solution :)