ci: add coverage reporting to pr-check workflow (#14)

* ci: add coverage reporting to pr-check workflow

Run cargo-llvm-cov on Ubuntu only and upload the resulting LCOV
report to Codecov via codecov/codecov-action. The three coverage
steps are guarded by `if: matrix.os == 'ubuntu-24.04'` so macOS
and Windows matrix legs are unaffected.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Philippe Martin <phmartin@redhat.com>

* chore: add kaiden workspace config with cargo-llvm-cov feature

Adds a Kaiden workspace definition that provisions Rust and a
custom cargo-llvm-cov devcontainer feature, making coverage tools
available in the development environment out of the box.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Philippe Martin <phmartin@redhat.com>

---------

Signed-off-by: Philippe Martin <phmartin@redhat.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: feloy

.github/workflows/pr-check.yml

@@ -52,3 +52,20 @@ jobs:
 
       - name: Test
         run: cargo test
+
+      - name: Install cargo-llvm-cov
+        if: matrix.os == 'ubuntu-24.04'
+        uses: taiki-e/install-action@65851e10cd6c377f11a60e600abc07cb08643468 # v2.79.3
+        with:
+          tool: cargo-llvm-cov
+
+      - name: Generate coverage report
+        if: matrix.os == 'ubuntu-24.04'
+        run: cargo llvm-cov --lcov --output-path lcov.info
+
+      - name: Upload coverage to Codecov
+        if: matrix.os == 'ubuntu-24.04'
+        uses: codecov/codecov-action@cddd853df119a48c5be31a973f8cd97e12e35e16 # v6.0.1
+        with:
+          files: lcov.info
+          token: ${{ secrets.CODECOV_TOKEN }}

.kaiden/features/cargo-llvm-cov/devcontainer-feature.json

@@ -0,0 +1,12 @@
+{
+  "id": "cargo-llvm-cov",
+  "version": "1.0.0",
+  "name": "cargo-llvm-cov",
+  "description": "Installs cargo-llvm-cov for LLVM-based code coverage",
+  "containerEnv": {
+    "CARGO_HOME": "/home/agent/.cargo"
+  },
+  "installsAfter": [
+    "ghcr.io/devcontainers/features/rust"
+  ]
+}

.kaiden/features/cargo-llvm-cov/install.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+set -e
+
+cargo +stable install cargo-llvm-cov --locked
+rustup component add llvm-tools-preview --toolchain stable

.kaiden/workspace.json

@@ -0,0 +1,6 @@
+{
+  "features": {
+    "ghcr.io/devcontainers/features/rust:1": {},
+    "./features/cargo-llvm-cov": {}
+  }
+}