test failure mode when kat isn't installed

Author: ianbotsf

.github/actions/emit-metrics/action.yml

@@ -1,5 +1,5 @@
 name: Emit Metrics
-description: Emit metrics from another workflow/action using the kat tool
+description: Emit metrics using the kat tool
 inputs:
   namespace:
     description: The CloudWatch namespace in which to emit metrics
@@ -40,6 +40,9 @@ inputs:
 runs:
   using: composite
   steps:
+    - name: Verify kat exists
+      shell: bash
+      run: which kat || ( echo Cannot find kat installation. Did you forget to run setup-kat first? && exit 1 )
     - name: Emit Metrics
       shell: bash
       run: |

.github/workflows/test-emit-metrics.yml

@@ -32,3 +32,28 @@ jobs:
           metrics: |
             BuildTime:4.532:Seconds
             BuildSucceeded:1:Count
+
+  fail-when-kat-unavailable:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+      - name: Fail to emit some test metrics
+        uses: ./.github/actions/emit-metrics
+        continue-on-error: true
+        with:
+          namespace: Test Namespace (ignore me)
+          dimensions: |
+            Artifact=foo-artifact
+            Platform=Kotlin/JVM
+            Variant=External
+          metrics: |
+            BuildTime:4.532:Seconds
+            BuildSucceeded:1:Count
+      - name: Handle expected failure
+        if: ${{ failure() }}
+        shell: bash
+        run: |
+          echo Saw expected failure from attempting to emit metrics when kat isn't installed.
+          echo All good now!
+          exit 0