Fix error that moves the Prebuild phase script after the source phase

[samuelsainz]

Description

Once I configure XCRemoteCache using the cocoapods plugin, when I reinstall the pods the script moves the "Prebuild" phase after the "Compile sources" phase.

Solution

Moving the Prebuild build phase is needed only the first time we insert it in the target build phases. When the build phase exists then it is already in the right order.

[polac24]

From what I see, the cocoapods plugin doesn't reorder build phases but it just shuffles them in the .pbxproj. Am I right?

If so, can we integrate also a check that ensures that Xcode build phases order is valid (as expected) and indeed we don't have to modify .pbxproj at all? I am just afraid that without that, we could lead to a wrong order if someone used a version prior to #74.

[samuelsainz]

Hi @polac24, thanks for reviewing this :)

I am not sure if I follow but the order in the .pbxproj actually defines the build phases order—i.e. If I move the order of the build phases for a target in the Xcode it is modified in the .pbxproj and viceversa.

To clarify a bit, what is happening is this:

• The first time I set XCRemoteCache with the cocoapods plugin the Prebuild phase is in the right place, before the Sources build phase (see the red line of code in the attached image)
• The second time I run pod install it moves the Prebuild script after the Sources build phase (see green line of code)
• The third time it will move it again before the Sources, and so on..

The bug is because of this code being executed every time we run pod install—assuming the Prebuild phase is after the Sources phase:

compile_phase_index = target.build_phases.index(target.source_build_phase) 
target.build_phases.insert(compile_phase_index, target.build_phases.delete(prebuild_script)) 

1. First it gets the Sources build phase index, which is 2 in my example
2. Deletes the prebuild phase, which was at index 1, leaving the Sources build phase at index 1
3. Inserts the prebuild phase at index 2

[polac24]

Thanks, now it makes sense. I was able to reproduce that every second time, the order is indeed incorrect.