Add code coverage in GitHub Actions

Author: sunsided

.github/workflows/rust.yml

@@ -1,24 +1,69 @@
+---
 name: Rust
 
 on:
   push:
     branches: [ "main" ]
+    paths:
+      - 'Cargo.toml'
+      - 'Cargo.lock'
+      - 'src/**'
+      - 'crates/**'
+      - 'bins/**'
+      - '.github/workflows/rust.yml'
   pull_request:
     branches: [ "main" ]
+    paths:
+      - 'Cargo.toml'
+      - 'Cargo.lock'
+      - 'src/**'
+      - 'crates/**'
+      - 'bins/**'
+      - '.github/workflows/rust.yml'
 
 env:
   CARGO_TERM_COLOR: always
 
 jobs:
   build:
+    name: Build and Test
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, macos-latest, windows-latest ]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check format
+        run: cargo fmt --check
+      - name: Build
+        run: cargo build --verbose
+      - uses: taiki-e/install-action@nextest
+      - name: Run tests
+        run: cargo nextest run --verbose --all-features
+      - name: Run doctests
+        run: cargo test --doc --verbose --all-features
 
+  codecov:
+    name: Code Coverage
     runs-on: ubuntu-latest
-
+    env:
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
     steps:
-    - uses: actions/checkout@v3
-    - name: Build
-      run: cargo build --verbose
-    - name: Run tests
-      run: cargo test --tests --verbose
-    - name: Run doctests
-      run: cargo test --doc --verbose
+      - uses: actions/checkout@v4
+      - name: Build
+        run: cargo build --verbose
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: llvm-tools-preview
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Install nextest
+        uses: taiki-e/install-action@nextest
+      - name: Generate code coverage
+        run: cargo llvm-cov nextest --all-features --workspace --lcov --output-path lcov.info
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4.0.1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: lcov.info
+          fail_ci_if_error: true

README.md

@@ -1,5 +1,7 @@
 # A query string builder for percent encoding key-value pairs
 
+[![codecov](https://codecov.io/gh/sunsided/query-string-builder/graph/badge.svg?token=HUCXM04DOG)](https://codecov.io/gh/sunsided/query-string-builder)
+
 This is a tiny helper crate for simplifying the construction of URL query strings.
 The initial `?` question mark is automatically prepended.
 

src/lib.rs

@@ -218,7 +218,7 @@ impl QueryString {
 impl Display for QueryString {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         if self.pairs.is_empty() {
-            return Ok(());
+            Ok(())
         } else {
             write!(f, "?")?;
             for (i, pair) in self.pairs.iter().enumerate() {