Add GitHub actions jobs which runs golden-diff for each test case

Author: simu

.github/workflows/test.yml

@@ -31,3 +31,22 @@ jobs:
           pattern: |
             *.sh
             step-*
+
+  test_gitlab_generator_script_define_cases:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Find test cases
+        run: |
+          make -sC gitlab list_test_instances >> "$GITHUB_OUTPUT"
+
+  test_gitlab_generator_script:
+    needs: test_gitlab_generator_script_define_cases
+    strategy:
+      matrix:
+        instance: ${{ fromJSON(needs.test_gitlab_generator_script_define_cases.outputs.instances) }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: |
+          make -C gitlab golden-diff -e instance=${{ matrix.instance }}

gitlab/Makefile

@@ -35,3 +35,8 @@ gen-golden-all: $(test_instances)
 .PHONY: $(test_instances)
 $(test_instances):
 	$(MAKE) $(recursive_target) -e instance=$(basename $(@F))
+
+.PHONY: list_test_instances
+list_test_instances: JSONNET_ENTRYPOINT=jsonnet
+list_test_instances:
+	$(JSONNET_DOCKER) --ext-str instances="$(test_instances)" -e 'std.split(std.extVar("instances"), " ")'