chore: add workflow to self test the action

.github/workflows/self-test.yml

@@ -0,0 +1,71 @@
+name: 'self-test'
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+      - 'releases/*'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  changed:
+    name: Detects changes between charts
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: azure/setup-helm@v5
+
+      - name: Diff Helm Chart
+        uses: ./
+        id: diff
+        with:
+          currentChartPath: ./__tests__/fixtures/charts/current
+          targetChartPath: ./__tests__/fixtures/charts/target
+          valuesPath: __tests__/fixtures/values.yaml
+          currentValuesRepo: ${{ github.repository }}
+          currentValuesBranch: ${{ github.sha }}
+          targetValuesBranch: ${{ github.sha }}
+
+      - name: Assert outputs
+        env:
+          CHANGED: ${{ steps.diff.outputs.changed }}
+          DIFF: ${{ steps.diff.outputs.diff }}
+          TARGET_TEMPLATE: ${{ steps.diff.outputs.targetTemplate }}
+        run: |
+          set -euo pipefail
+          test "$CHANGED" = "true" || { echo "expected changed=true, got '$CHANGED'"; exit 1; }
+          grep -q '^+  replicas: "2"' <<< "$DIFF" || { echo "diff is missing the added line:"; echo "$DIFF"; exit 1; }
+          grep -q '^```diff' <<< "$DIFF" || { echo "diff is not formatted as markdown"; exit 1; }
+          grep -q 'replicas: "2"' <<< "$TARGET_TEMPLATE" || { echo "targetTemplate is missing the target render:"; echo "$TARGET_TEMPLATE"; exit 1; }
+
+  unchanged:
+    name: Detects identical charts
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: azure/setup-helm@v5
+
+      - name: Diff Helm Chart
+        uses: ./
+        id: diff
+        with:
+          currentChartPath: ./__tests__/fixtures/charts/current
+          targetChartPath: ./__tests__/fixtures/charts/current
+          valuesPath: __tests__/fixtures/values.yaml
+          currentValuesRepo: ${{ github.repository }}
+          currentValuesBranch: ${{ github.sha }}
+          targetValuesBranch: ${{ github.sha }}
+
+      - name: Assert outputs
+        env:
+          CHANGED: ${{ steps.diff.outputs.changed }}
+          DIFF: ${{ steps.diff.outputs.diff }}
+        run: |
+          set -euo pipefail
+          test "$CHANGED" = "false" || { echo "expected changed=false, got '$CHANGED'"; exit 1; }
+          test -z "$DIFF" || { echo "expected empty diff, got:"; echo "$DIFF"; exit 1; }

README.md

@@ -22,6 +22,7 @@ Add the following step to your workflow:
     currentValuesRepo: fivekoalas/diff-helm-chart
     targetValuesRepo: fivekoalas/diff-helm-chart # optional, defaults to currentValuesRepo
     currentValuesBranch: main # optional, defaults to develop
+    targetValuesBranch: main # optional, defaults to develop, overridden by targetBranchRegex on pull requests
     token: ${{ secrets.GITHUB_TOKEN }} # required PAT for private repos, optional for public repos defaults to GITHUB_TOKEN
     targetBranchRegex: 'release-.*' # optional, defaults to 'target: (.*)'
     asMarkdown: true # optional, defaults to true

__tests__/fixtures/charts/current/Chart.yaml

@@ -0,0 +1,5 @@
+apiVersion: v2
+name: fixture
+description: Chart used to self-test the action
+type: application
+version: 0.1.0

__tests__/fixtures/charts/current/templates/configmap.yaml

@@ -0,0 +1,6 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-config
+data:
+  greeting: {{ .Values.greeting | quote }}

__tests__/fixtures/charts/target/Chart.yaml

@@ -0,0 +1,5 @@
+apiVersion: v2
+name: fixture
+description: Chart used to self-test the action
+type: application
+version: 0.1.0

__tests__/fixtures/charts/target/templates/configmap.yaml

@@ -0,0 +1,7 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-config
+data:
+  greeting: {{ .Values.greeting | quote }}
+  replicas: {{ .Values.replicas | quote }}

__tests__/fixtures/values.yaml

@@ -0,0 +1,2 @@
+greeting: hello
+replicas: 2

action.yml

@@ -27,6 +27,10 @@ inputs:
     description: 'The branch containing the current values'
     required: false
     default: 'develop'
+  targetValuesBranch:
+    description: 'The branch containing the target values, used when the pull request body does not match targetBranchRegex'
+    required: false
+    default: 'develop'
   token:
     description: 'The Github token'
     default: '${{ github.token }}'

src/input.ts

@@ -14,7 +14,7 @@ export class Input {
       getInput('targetValuesRepo') || getInput('currentValuesRepo')
     const [owner, repo] = ownerWithRepo.split('/')
     const path = getInput('valuesPath')
-    let ref = 'develop'
+    let ref = getInput('targetValuesBranch') || 'develop'
 
     if (context.eventName === 'pull_request') {
       const regex = new RegExp(getInput('targetBranchRegex'))