diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index db306b460ff..56b06d84c6a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,6 +1,6 @@
 name: build
 
-'on':
+on:
   pull_request:
   workflow_dispatch:
   schedule:
@@ -11,22 +11,31 @@ jobs:
     name: cargo fmt
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: cargo fmt
-      run: cargo fmt --all -- --check
-   
+      - uses: actions/checkout@v4
+      - name: cargo fmt
+        run: cargo fmt --all -- --check
+
   clippy:
     name: cargo clippy
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: cargo clippy
-      run: cargo clippy --all --all-targets -- -D warnings
-  
+      - uses: actions/checkout@v4
+      - name: cargo clippy
+        run: cargo clippy --all --all-targets -- -D warnings
+
   test:
     name: cargo test
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: cargo test
-      run: cargo test
+      - uses: actions/checkout@v4
+      - name: cargo test
+        run: cargo test --all -- --test-threads=1
+
+      - name: Install codecov
+        run: |
+          curl -Os https://uploader.codecov.io/latest/linux/codecov
+          chmod +x codecov
+          sudo mv codecov /usr/local/bin
+
+      - name: Upload coverage to Codecov
+        run: codecov -f target/debug/deps/*.gcov -t ${{ secrets.CODECOV_TOKEN }} || echo "Codecov upload failed"
diff --git a/src/string/reverse.rs b/src/string/reverse.rs
index bf17745a147..1fb997be653 100644
--- a/src/string/reverse.rs
+++ b/src/string/reverse.rs
@@ -15,6 +15,7 @@ pub fn reverse(text: &str) -> String {
 mod tests {
     use super::*;
 
+    // Macro for generating test cases
     macro_rules! test_cases {
         ($($name:ident: $test_case:expr,)*) => {
             $(
@@ -27,6 +28,7 @@ mod tests {
         };
     }
 
+    // Using the macro to define various test cases
     test_cases! {
         test_simple_palindrome: ("racecar", "racecar"),
         test_non_palindrome: ("abcdef", "fedcba"),