Add coverage reporting

.github/actions/print-build-versions/action.yml

@@ -10,6 +10,10 @@ inputs:
     description: "Path to Cargo.lock used as a fallback source for the wasm-bindgen version"
     required: false
     default: "src/Cargo.lock"
+  jacoco-version:
+    description: "JaCoCo version, resolved by Gradle during the build rather than from a runner CLI"
+    required: false
+    default: ""
 
 runs:
   using: composite
@@ -18,6 +22,7 @@ runs:
       shell: bash
       env:
         CARGO_LOCK: ${{ inputs.cargo-lock }}
+        JACOCO_VERSION: ${{ inputs.jacoco-version }}
       run: |
         echo "::group::Build tool versions ($(uname -s) $(uname -m))"
         echo "os:           $(uname -srm)"
@@ -64,4 +69,6 @@ runs:
         fi
         if command -v cargo-about  >/dev/null 2>&1; then echo "cargo-about:  $(cargo-about --version 2>/dev/null | head -1)"; else echo "cargo-about:  not installed"; fi
         if command -v cargo-audit  >/dev/null 2>&1; then echo "cargo-audit:  $(cargo-audit --version 2>/dev/null | head -1)"; else echo "cargo-audit:  not installed"; fi
+        if command -v cargo-llvm-cov >/dev/null 2>&1; then echo "cargo-llvm-cov: $(cargo-llvm-cov --version 2>/dev/null | head -1)"; else echo "cargo-llvm-cov: not installed"; fi
+        if [ -n "$JACOCO_VERSION" ]; then echo "jacoco:       $JACOCO_VERSION (resolved by Gradle)"; fi
         echo "::endgroup::"

.github/workflows/configs.yml

@@ -45,6 +45,12 @@ on:
       cargo-audit-version:
         description: "cargo-audit version"
         value: ${{ jobs.get-configs.outputs.cargo-audit-version }}
+      cargo-llvm-cov-version:
+        description: "cargo-llvm-cov version"
+        value: ${{ jobs.get-configs.outputs.cargo-llvm-cov-version }}
+      jacoco-version:
+        description: "JaCoCo version for the JVM binding coverage report"
+        value: ${{ jobs.get-configs.outputs.jacoco-version }}
 
 permissions:
   contents: read
@@ -67,6 +73,8 @@ jobs:
       WASM_PACK_VERSION: '0.14.0'
       CARGO_ABOUT_VERSION: '0.9.0'
       CARGO_AUDIT_VERSION: '0.22.2'
+      CARGO_LLVM_COV_VERSION: '0.8.7'
+      JACOCO_VERSION: '0.8.13'          # keep in sync with bindings-jvm/tests/kotlin/build.gradle.kts
     outputs:
       app-name: ${{ env.APP_NAME }}
       working-dir: ${{ env.WORKING_DIR }}
@@ -82,6 +90,8 @@ jobs:
       wasm-pack-version: ${{ env.WASM_PACK_VERSION }}
       cargo-about-version: ${{ env.CARGO_ABOUT_VERSION }}
       cargo-audit-version: ${{ env.CARGO_AUDIT_VERSION }}
+      cargo-llvm-cov-version: ${{ env.CARGO_LLVM_COV_VERSION }}
+      jacoco-version: ${{ env.JACOCO_VERSION }}
     steps:
       - name: Provide configs
         run: |
@@ -99,3 +109,5 @@ jobs:
           echo "wasm-pack-version   = ${{ env.WASM_PACK_VERSION }}"
           echo "cargo-about-version = ${{ env.CARGO_ABOUT_VERSION }}"
           echo "cargo-audit-version = ${{ env.CARGO_AUDIT_VERSION }}"
+          echo "cargo-llvm-cov-version = ${{ env.CARGO_LLVM_COV_VERSION }}"
+          echo "jacoco-version      = ${{ env.JACOCO_VERSION }}"

.github/workflows/validate.yml

@@ -96,6 +96,8 @@
   test:
     needs: [ format, lint, audit, get-configs ]
     runs-on: ubuntu-latest
+    env:
+      WORKING_DIR: ${{ needs.get-configs.outputs.working-dir }}
     steps:
     - uses: actions/checkout@v6
       with:
@@ -105,18 +107,24 @@
       uses: dtolnay/rust-toolchain@stable
       with:
         toolchain: ${{ needs.get-configs.outputs.rust-toolchain }}
+        components: llvm-tools-preview
 
     - name: Cache Cargo
       uses: Swatinem/rust-cache@v2
       with:
-        workspaces: ${{ needs.get-configs.outputs.working-dir }}
+        workspaces: ${{ env.WORKING_DIR }}
+
+    - name: Install cargo-llvm-cov ${{ needs.get-configs.outputs.cargo-llvm-cov-version }}
+      uses: taiki-e/install-action@v2
+      with:
+        tool: cargo-llvm-cov@${{ needs.get-configs.outputs.cargo-llvm-cov-version }}
 
     - name: Log tool versions
       uses: ./.github/actions/print-build-versions
 
     - name: Test
-      working-directory: ${{ needs.get-configs.outputs.working-dir }}
-      run: cargo test --locked --release --workspace --no-fail-fast
+      working-directory: ${{ env.WORKING_DIR }}
+      run: cargo llvm-cov --locked --release --workspace --no-fail-fast
 
   test-jvm:
     needs: [ format, lint, audit, get-configs ]
@@ -149,6 +157,8 @@
 
     - name: Log tool versions
       uses: ./.github/actions/print-build-versions
+      with:
+        jacoco-version: ${{ needs.get-configs.outputs.jacoco-version }}
 
     - name: Test
       working-directory: ${{ env.WORKING_DIR }}/bindings-jvm/tests

.gitignore

@@ -16,6 +16,7 @@ src/bindings-jvm/generated/**/*
 # Node / WASM
 **/node_modules/
 **/package-lock.json
+!src/bindings-wasm/package-lock.json
 
 # Output (regenerable)
 **/output/**
@@ -24,6 +25,7 @@ src/data-source/generated/patched_schemas/
 src/**/reports/
 **/cdk.out/
 *.pyc
+**/coverage/**
 
 # IDE
 **/*.iml

src/bindings-jvm/tests/kotlin/build.gradle.kts

@@ -1,11 +1,16 @@
 plugins {
     kotlin("jvm") version "2.3.10"
+    jacoco
 }
 
 repositories {
     mavenCentral()
 }
 
+jacoco {
+    toolVersion = "0.8.13"
+}
+
 val bindingsJar = file("${rootProject.projectDir}/../../generated/cloudformation-validate.jar")
 
 dependencies {
@@ -27,6 +32,49 @@ tasks.test {
         showStackTraces = true
         exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
     }
+
+    finalizedBy(tasks.jacocoTestReport)
+}
+
+tasks.jacocoTestReport {
+    classDirectories.setFrom(
+        zipTree(bindingsJar).matching {
+            include("com/amazonaws/cloudformation/validation/**/*.class")
+            exclude(
+                "**/FfiConverter*",
+                "**/ForeignBytes*",
+                "**/RustBuffer*",
+                "**/Uniffi*",
+                "**/*Cleaner*",
+                "**/NoPointer*",
+                "**/UByteArray*",
+            )
+        },
+    )
+
+    reports {
+        xml.required.set(true)
+        html.required.set(true)
+    }
+
+    doLast {
+        val reportFile = reports.xml.outputLocation.get().asFile
+        val factory = javax.xml.parsers.DocumentBuilderFactory.newInstance()
+        factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false)
+        val report = factory.newDocumentBuilder().parse(reportFile).documentElement
+        val counters = report.childNodes
+        println("Kotlin coverage:")
+        for (i in 0 until counters.length) {
+            val node = counters.item(i)
+            if (node.nodeName != "counter") continue
+            val type = node.attributes.getNamedItem("type").nodeValue
+            val covered = node.attributes.getNamedItem("covered").nodeValue.toInt()
+            val missed = node.attributes.getNamedItem("missed").nodeValue.toInt()
+            val total = covered + missed
+            val pct = if (total > 0) 100.0 * covered / total else 0.0
+            println("  %-12s %6d/%-6d %6.2f%%".format(type, covered, total, pct))
+        }
+    }
 }
 
 kotlin {

src/bindings-jvm/tests/run.sh

@@ -7,4 +7,4 @@ KOTLIN_DIR="$SCRIPT_DIR/kotlin"
 
 echo "Running Kotlin smoke tests..."
 cd "$KOTLIN_DIR"
-gradle test --no-daemon --rerun-tasks
+gradle test jacocoTestReport --no-daemon --rerun-tasks --console=rich

src/bindings-wasm/build.sh

@@ -32,7 +32,7 @@ if [ -f "$WASM_DTS" ] && ! grep -q "^export type JsonValue" "$WASM_DTS"; then
 fi
 
 cd "$SCRIPT_DIR"
-npm ci --silent 2>/dev/null
+npm ci --silent
 npm run build:ts
 
 # ── Package metadata ──────────────────────────────────────────────────────────

src/bindings-wasm/tests/package.json

@@ -1,10 +1,12 @@
 {
     "private": true,
     "scripts": {
-        "test": "vitest run"
+        "test": "vitest run",
+        "test:coverage": "vitest run --coverage"
     },
     "devDependencies": {
         "vitest": "4.1.8",
+        "@vitest/coverage-v8": "4.1.8",
         "@types/node": "25.9.3"
     }
 }

src/bindings-wasm/tests/run.sh

@@ -6,5 +6,5 @@ BINDINGS_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
 
 echo "Running smoke tests..."
 cd "$SCRIPT_DIR"
-npm ci --silent 2>/dev/null
-npm test
+npm install --silent
+npm run test:coverage

src/bindings-wasm/tests/vitest.config.ts

@@ -1,15 +1,20 @@
-import { defineConfig } from "vitest/config";
+import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
-  test: {
-    testTimeout: 120_000,
-    hookTimeout: 120_000,
-    teardownTimeout: 120_000,
-    pool: "threads",
-    poolOptions: {
-      threads: {
-        singleThread: true,
-      },
+    root: '..',
+    test: {
+        include: ['tests/**/*.test.ts'],
+        testTimeout: 120_000,
+        hookTimeout: 120_000,
+        teardownTimeout: 120_000,
+        fileParallelism: false,
+        coverage: {
+            provider: 'v8',
+            include: ['dist/**/*.js'],
+            exclude: ['dist/package.json'],
+            reporter: ['text', 'lcov', 'json-summary'],
+            reportsDirectory: 'tests/coverage',
+            reportOnFailure: true,
+        },
     },
-  },
 });