Is it possible to make a defined step conditional when using it in a Bitbucket pipeline? - bitbucket

Question

I have a monorepo with a bitbucket pipeline.
I want to be able to run a default build whenever I push that only runs the steps for projects in the monorepo that have changed, using a step definition for each project. But I want to be able to run customs builds for specific environments that run for every project using the same step definitions.
If I define a step that I want to use in several places, e.g.
definitions:
steps:
- step: &ExampleProjectBuildStep
name: Example Project Build Step
script:
- echo 'Example project build step'
- step: &ExampleProjectBuildStep2
name: Example Project Build Step 2
script:
- echo 'Example project build step 2'
I'd like to be able to run a parallel conditional default build:
pipelines:
default:
- parallel
- step: *ExampleProjectBuildStep
condition:
changesets:
includePaths:
- "example_path/**"
- step: *ExampleProjectBuildStep2
condition:
changesets:
includePaths:
- "example_path_2/**"
example_custom_pipeline:
- step: *ExampleProjectBuildStep
- step: *ExampleProjectBuildStep2
I also want to use the defined step in custom/branch pipeline builds without the condition.
I have a separate monorepo project which is simpler, so I haven't defined the steps there, and the parallel conditional steps work as expected. Is is just not possible to have conditional steps that use a step definition in bitbucket without including the conditional in the definition and thus requiring two definitions, one conditional and one unconditional?
None of the documentation I've found that covers conditional steps mentions step definitions, and vice versa. I can't find any info on whether this should be possible, but it seems like a surprising oversight if it isn't.
I've tried to make this as clear as possible, but if anything is unclear please highlight and I will try to better explain what I mean.

Answer 1

It is possible to override some of the attributes of an anchor definition with YAML operators.
The way I resolve this in monorepos is usually:
definitions:
yaml-anchors:
- &some-step
name: A step
condition:
changesets:
includePaths:
- subproject/**
script:
- echo "example"
pipelines:
default:
- step: *some-step
custom:
example:
- step:
<<: *some-step
condition: null