feat: add Tarpaulin-based code coverage reporting

.github/workflows/coverage.yml

@@ -0,0 +1,53 @@
+name: Code Coverage
+
+on:
+  push:
+    branches: [main, dev]
+  pull_request:
+    branches: [main, dev]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    name: Generate Coverage Report
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Rust Cache
+        uses: Swatinem/rust-cache@v2
+
+      - name: Install cargo-tarpaulin
+        run: cargo install cargo-tarpaulin
+
+      - name: Generate coverage report
+        run: |
+          cargo tarpaulin \
+            --workspace \
+            --out Xml \
+            --output-dir coverage \
+            --timeout 300 \
+            --exclude-files "tests/*" \
+            --ignore-panics
+
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ./coverage/cobertura.xml
+          flags: rust
+          name: coverage-report
+          fail_ci_if_error: false
+          verbose: true
+
+      - name: Archive coverage report
+        if: always()
+        uses: actions/upload-artifact@v5
+        with:
+          name: coverage-report
+          path: coverage/

.tarpaulin.toml

@@ -0,0 +1,4 @@
+[coverage]
+timeout = 300
+ignore-panics = true
+exclude-files = ["tests/*", "benches/*"]

README.md

@@ -3,6 +3,7 @@
 ![WebARKitLib-rs](./assets/WebARKitLib-Rust-banner.jpg)
 
 [![CI](https://github.com/webarkit/WebARKitLib-rs/actions/workflows/ci.yml/badge.svg)](https://github.com/webarkit/WebARKitLib-rs/actions/workflows/ci.yml)
+[![codecov](https://codecov.io/gh/webarkit/WebARKitLib-rs/branch/main/graph/badge.svg)](https://codecov.io/gh/webarkit/WebARKitLib-rs)
 [![Crates.io](https://img.shields.io/crates/v/webarkitlib-rs.svg)](https://crates.io/crates/webarkitlib-rs)
 [![npm](https://img.shields.io/npm/v/@webarkit/webarkitlib-wasm.svg)](https://www.npmjs.com/package/@webarkit/webarkitlib-wasm)
 [![GitHub stars](https://img.shields.io/github/stars/webarkit/WebARKitLib-rs.svg?style=social)](https://github.com/webarkit/WebARKitLib-rs/stargazers)
@@ -263,6 +264,36 @@ Because it's the `log` crate facade, any compatible backend works:
 
 No library code change is needed — pick the backend in your application's entry point.
 
+## 📈 Code Coverage
+
+Coverage reports are generated automatically on every push and pull request via the [coverage workflow](.github/workflows/coverage.yml) using [cargo-tarpaulin](https://github.com/xd009642/tarpaulin) and uploaded to [Codecov](https://codecov.io/gh/webarkit/WebARKitLib-rs).
+
+### Generate a Coverage Report Locally
+
+```bash
+# Install tarpaulin (once)
+cargo install cargo-tarpaulin
+
+# Run the helper script — produces coverage/index.html
+./scripts/coverage.sh
+```
+
+Or run tarpaulin directly:
+
+```bash
+cargo tarpaulin --workspace --out Html --output-dir coverage --timeout 300
+```
+
+### Coverage Targets
+
+| Area | Target |
+|------|--------|
+| Minimum overall | 75 % |
+| Desirable overall | 85 %+ |
+| Marker tracking (critical path) | 95 %+ |
+
+---
+
 ## 📊 Benchmarking
 
 We maintain a strict performance comparison with the original C library to ensure our Rust port remains competitive. 

scripts/coverage.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# coverage.sh — Generate a local HTML code coverage report using cargo-tarpaulin.
+#
+# Usage:
+#   ./scripts/coverage.sh
+#
+# Requires cargo-tarpaulin to be installed:
+#   cargo install cargo-tarpaulin
+set -e
+
+echo "🧪 Generating Code Coverage Report..."
+echo ""
+
+# Clean previous coverage output
+rm -rf coverage/
+mkdir -p coverage/
+
+echo "Using Tarpaulin for coverage..."
+cargo tarpaulin \
+    --workspace \
+    --out Html \
+    --output-dir coverage \
+    --timeout 300 \
+    --exclude-files "tests/*" \
+    --ignore-panics \
+    --verbose
+
+echo ""
+echo "✅ Coverage report generated!"
+echo ""
+echo "📊 Open the report:"
+if command -v open &> /dev/null; then
+    open coverage/index.html        # macOS
+elif command -v xdg-open &> /dev/null; then
+    xdg-open coverage/index.html   # Linux
+else
+    echo "   $(pwd)/coverage/index.html"
+fi