Formalize PR process for breaking changes (#2289)

* Formalize PR process for breaking changes

* Probably works.. right?

* modular

* now should work

* Added get-pr-branch action

* remove workflows

* get-pr-branch.yml as workflow

* moving things around

* moving again

* Add other tutorials

* Revert "remove workflows"

This reverts commit 7f3172a2884640e3f2024be99aea85aee4f00ada.

* description

* description

* Revert "description"

This reverts commit c04cb24eea3cde457be084a9f4c7af72c114643e.

.github/workflows/build-tutorial-hello-world.yml

@@ -14,10 +14,18 @@ on:
       - '.github/ISSUE_TEMPLATE/**'
 
 jobs:
+  get-branch:
+    name: "Get target branch"
+    uses: ./.github/workflows/reusable-get-pr-branch.yml
+    with:
+      target_repository: fprime-community/fprime-tutorial-hello-world
+
   run:
+    needs: get-branch
     name: ""
-    uses: ./.github/workflows/reusable-builder.yml
+    uses: ./.github/workflows/reusable-project-builder.yml
     with:
       target_repository: fprime-community/fprime-tutorial-hello-world
       build_location: HelloWorldDeployment
       run_unit_tests: true
+      target_ref: ${{ needs.get-branch.outputs.target-branch }}

.github/workflows/build-tutorial-led-blinker.yml

@@ -14,10 +14,18 @@ on:
       - '.github/ISSUE_TEMPLATE/**'
 
 jobs:
+  get-branch:
+    name: "Get target branch"
+    uses: ./.github/workflows/reusable-get-pr-branch.yml
+    with:
+      target_repository: fprime-community/fprime-workshop-led-blinker
+
   run:
+    needs: get-branch
     name: ""
-    uses: ./.github/workflows/reusable-builder.yml
+    uses: ./.github/workflows/reusable-project-builder.yml
     with: 
       target_repository: fprime-community/fprime-workshop-led-blinker
       build_location: LedBlinker
       run_unit_tests: true
+      target_ref: ${{ needs.get-branch.outputs.target-branch }}

.github/workflows/build-tutorial-math-comp.yml

@@ -14,10 +14,18 @@ on:
       - '.github/ISSUE_TEMPLATE/**'
 
 jobs:
+  get-branch:
+    name: "Get target branch"
+    uses: ./.github/workflows/reusable-get-pr-branch.yml
+    with:
+      target_repository: fprime-community/fprime-tutorial-math-component
+
   run:
+    needs: get-branch
     name: ""
-    uses: ./.github/workflows/reusable-builder.yml
+    uses: ./.github/workflows/reusable-project-builder.yml
     with: 
       target_repository: fprime-community/fprime-tutorial-math-component
       build_location: MathDeployment
       run_unit_tests: true
+      target_ref: ${{ needs.get-branch.outputs.target-branch }}

.github/workflows/reusable-get-pr-branch.yml

@@ -0,0 +1,42 @@
+# If the event that triggered this action is a PR and has a matching `pr-<number>` branch on
+# target_repository, then return the name of that branch. Otherwise, return default_target_ref.
+# See the CONTRIBUTING.md for info on why this is used.
+
+name: 'Get PR Branch'
+
+on:
+  workflow_call:
+    inputs:
+      target_repository:
+        description: 'The repository to check for the PR branch'
+        type: string
+        required: true
+      default_target_ref:
+        description: 'Ref to use if the PR branch is not found'
+        type: string
+        required: false
+        default: devel
+    outputs:
+      target-branch:
+        value: ${{ jobs.runs.outputs.target-branch }}
+
+jobs:
+  runs:
+    runs-on: "ubuntu-latest"
+    outputs:
+      target-branch: ${{ steps.get_target_branch.outputs.TARGET_BRANCH }}
+    steps:
+      - name: "Get target branch"
+        id: get_target_branch
+        run: |
+          response_code=`curl -w '%{response_code}' https://api.github.com/repos/${{ inputs.target_repository }}/branches/pr-${{ github.event.number }} -o /dev/null`
+          if [[ "${{ github.event_name }}" == "pull_request" && "$response_code" == "200" ]]; then
+            echo "TARGET_BRANCH=pr-${{ github.event.number }}" >> $GITHUB_OUTPUT
+            echo "PR branch found, using pr-${{ github.event.number }}"
+          else
+            echo "TARGET_BRANCH=${{ inputs.default_target_ref }}" >> $GITHUB_OUTPUT
+            echo "PR branch not found, using ${{ inputs.default_target_ref }}"
+          fi
+        shell: bash
+
+

.github/workflows/reusable-project-builder.yml

@@ -41,6 +41,7 @@ on:
         default: "devel"
 
 jobs:
+
   build:
     runs-on: ${{ inputs.runs_on }}
     name: "Build"

CONTRIBUTING.md

@@ -117,6 +117,15 @@ the end, these checks must pass for the submission to continue.
 If something seems amiss with one of these checks ask for help on your PR and a maintainer will do their best to help
 get the submission moving forward.
 
+### Automated Checks on Reference Repositories
+
+Some of the above-mentioned automated checks run on reference applications that are not part of the core F´ repository, such as our [tutorial repositories](https://github.com/fprime-community#tutorials). This serves two main purposes: running more tests, and making sure our suite of reference applications and tutorials do not go out-of-date.
+Because of this pattern, users who submit a pull request which introduces breaking changes on _how_ F´ is used in those external repositories will need to submit associated pull requests to introduce a fix on said external repositories. 
+
+The checks are configured to run on the `devel` branch of each external repository, but will prioritize the branch `pr-<PR_NUMBER>` if it exists, with `PR_NUMBER` being the number of the pull request that has been opened in nasa/fprime.
+
+Maintainers will gladly help you in this process.
+
 ## Final Approval and Submission
 
 Once all corrections have been made, automated checks are passing, and a maintainer has given final approval, it is time