Adopt a JaCoCo Method Filter extension

.github/copilot-instructions.md

@@ -18,6 +18,7 @@ StatusBoard is a real-time monitoring platform for tracking service health statu
 - **Database**: AWS DynamoDB for persistence
 - **Testing**: ZIO Test framework
 - **Code Coverage**: Jacoco
+- Compiler warnings treated as errors where configured; coverage ≥ 80% via JMF-enabled JaCoCo (excluding methods listed in `jmf-rules.txt`).
 
 ### Frontend (TypeScript)
 - **Framework**: Angular 19
@@ -166,6 +167,29 @@ The checker system uses a polymorphic design:
 - E2E tests: `npm run e2e` (Cypress via `cypress.json`)
 - Test coverage: `npm run test:coverage`
 
+## Coverage Filtering (JMF)
+
+### When a unit test adds value — write one
+- The method has any logic of its own.
+
+### When to add to `jmf-rules.txt` instead of writing a unit test
+- The body is a single call with no own logic: it forwards to another overload, calls its non-deprecated replacement, returns a field, or wraps a constructor with no transformation.
+- **Litmus test**: "Does this method have any logic of its own?" — No → add a JMF rule instead of a test.
+
+### Global rule collision check (CRITICAL)
+- When adding any new method, check whether its name matches a pattern in the `# GLOBAL RULES` section of `jmf-rules.txt`.
+- If a method name matches a global rule AND the method contains domain logic: immediately add an INCLUDE rescue rule (`+FQCN#method(*)`) in the `# INCLUDE RULES` section of `jmf-rules.txt`.
+- High-risk method names (most common collisions): `apply()`, `toString()`, `equals()`, `copy()`, `name()`, `groups()`, `optionalAttributes()`. See the `# GLOBAL RULES` section of `jmf-rules.txt` for the full list.
+- Rationale: broad global rules are designed for compiler-generated boilerplate and can silently suppress coverage for domain methods. INCLUDE rules rescue specific methods from broad exclusions.
+- Example: if adding `def apply(id: String): Record`, add `+*Record$#apply(*)  id:keep-record-factory` to the `# INCLUDE RULES` section to rescue it from the `*$*#apply(*)` global rule.
+
+### JMF drift check (review rule)
+- When modifying a method that already appears in `jmf-rules.txt`, verify its body still qualifies for exclusion.
+- If own logic has been added since the rule was created, remove the JMF rule and write a unit test instead.
+
+### Cannot add JMF rules for
+- Methods with branching logic, error handling, or non-trivial transformations — write a unit test instead.
+
 ## Configuration
 - Main config: `config. conf` (HOCON format)
 - Environment-specific configurations for different deployments
@@ -279,4 +303,4 @@ npm run sync-version         # Sync VERSION file to package.json
 ## Additional Resources
 - [Wiki - REST API](https://github.com/AbsaOSS/StatusBoard/wiki/REST-API)
 - [Wiki - Architecture](https://github.com/AbsaOSS/StatusBoard/wiki/Architecture)
-- [Wiki - Supported Checkers](https://github.com/AbsaOSS/StatusBoard/wiki/Supported-checkers)
+- [Wiki - Supported Checkers](https://github.com/AbsaOSS/StatusBoard/wiki/Supported-checkers)

.github/workflows/ci-check-jacoco.yml

@@ -1,22 +1,48 @@
-name: JaCoCo Report
+name: CI Check JaCoCo code-coverage
 
 on:
   pull_request:
     branches: [ master ]
-    types: [ opened, edited, synchronize, reopened ]
 
 env:
   scalaLong: 2.13.11
   scalaShort: "2.13"
-  coverage-overall: 80.0
-  coverage-changed-files: 80.0
-  coverage-per-changed-file: 0.0
-  check-overall-coverages: true
+  REPORT_GROUPS: |
+    - name: statusboard
+      paths:
+        - '**/target/**/jacoco-report/jacoco.xml'
+      thresholds: '77*80*60'
 
 jobs:
-  jacoco-report:
-    name: JaCoCo Report
+  detect:
+    name: Detect Changed Files
     runs-on: ubuntu-latest
+    timeout-minutes: 2
+    outputs:
+      scala_changed: ${{ steps.filter.outputs.scala }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+      - uses: dorny/paths-filter@fbd0ab8f3e69293af611ebaee6363fc25e6d187d
+        id: filter
+        with:
+          token: ""
+          filters: |
+            scala:
+              - '**/*.scala'
+              - '!project/**'
+
+  build-test-and-measure:
+    name: Build, Test and Measure
+    needs: detect
+    if: needs.detect.outputs.scala_changed == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      issues: write
+      pull-requests: write
     services:
       dynamodb-local:
         image: "amazon/dynamodb-local:latest"
@@ -51,16 +77,21 @@ jobs:
         with:
           python-version: '3.14'
 
-      - name: Publish JaCoCo Report in PR comments
+      - name: Check coverage thresholds and add reports in PR comments
         id: jacoco
         uses: MoranaApps/jacoco-report@69351d88d18f7697c416e1bc2020ed05606d8120
         with:
           token: '${{ secrets.GITHUB_TOKEN }}'
-          paths: |
-            **/target/**/jacoco/report/jacoco.xml
-          sensitivity: "detail"
-          comment-mode: 'single'
-          min-coverage-overall: ${{ env.coverage-overall }}
-          min-coverage-changed-files: ${{ env.coverage-changed-files }}
-          min-coverage-per-changed-file: ${{ env.coverage-per-changed-file }}
-          skip-unchanged: false
+          global-thresholds: '77*80'
+          report-thresholds-default: '0*0*0'
+          skip-unchanged: 'true'
+          evaluate-unchanged: 'false'
+          report-groups: ${{ env.REPORT_GROUPS }}
+
+  noop:
+    name: No Operation
+    needs: detect
+    if: needs.detect.outputs.scala_changed != 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "No changes in src/**/*.scala — passing."

build.sbt

@@ -55,7 +55,9 @@ lazy val root = (project in file("."))
     Test / parallelExecution := false,
     (assembly / test) := {},
     publish := {},
+    jmfReportFile   := Some(target.value / "jmf-report.json"),
+    jmfReportFormat := "json",
   )
   .enablePlugins(AutomateHeaderPlugin)
   .enablePlugins(AssemblyPlugin)
-  .enablePlugins(FilteredJacocoAgentPlugin)
+  .enablePlugins(JacocoFilterPlugin)