feat: adds coverage badge workflow

.github/workflows/go-coverage.yml

@@ -0,0 +1,42 @@
+name: Coverage
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v5
+      with:
+        fetch-depth: '0'
+
+    - name: Set up Go
+      uses: actions/setup-go@v6
+      with:
+        go-version: 1.24
+        cache: 'true'
+
+    - name: Build
+      run: go install
+
+    - name: Test
+      run: |
+        go test -v -cover ./... -coverprofile coverage.out -coverpkg ./...
+        go tool cover -func coverage.out -o coverage.out  # Replaces coverage.out with the analysis of coverage.out
+
+    - name: Go Coverage Badge
+      uses: tj-actions/coverage-badge-go@v3
+      with:
+        green: 80
+        filename: coverage.out
+
+    - uses: stefanzweifel/git-auto-commit-action@v6
+      id: auto-commit-action
+      with:
+        commit_message: Apply Code Coverage Badge
+        file_pattern: ./README.md

README.md

@@ -1,9 +1,9 @@
 # Exitplan
+[![Go Reference](https://pkg.go.dev/badge/github.com/struct0x/exitplan.svg)](https://pkg.go.dev/github.com/struct0x/exitplan)
+![Coverage](https://img.shields.io/badge/Coverage-83.2%25-brightgreen)
 
 A Go library for managing the lifecycle of an application with graceful shutdown capabilities.
 
-[![Go Reference](https://pkg.go.dev/badge/github.com/struct0x/exitplan.svg)](https://pkg.go.dev/github.com/struct0x/exitplan)
-
 ## Overview
 
 The Exitplan library provides a simple mechanism for managing the lifetime of an application. 

exitplan_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"slices"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -165,10 +166,10 @@ func TestOnExitTimeout(t *testing.T) {
 
 	l := exitplan.New()
 
-	called := false
+	called := atomic.Bool{}
 	l.OnExit(func() {
 		time.Sleep(2 * timeout)
-		called = true
+		called.Store(true)
 	}, exitplan.Timeout(timeout))
 
 	go func() {
@@ -186,7 +187,7 @@ func TestOnExitTimeout(t *testing.T) {
 		t.Errorf("expected timeout between %v and %v, got %v", timeout-timeoutJitter, timeout+timeoutJitter, end.Sub(start))
 	}
 
-	if called {
+	if called.Load() {
 		t.Error("callback was called")
 	}
 }