add tests coverare badge (#2)

* add tests coverare badge

* fix CODECOV_TOKEN

* fix issue

.github/workflows/test.yaml

@@ -0,0 +1,32 @@
+name: test
+
+env:
+  GO_VERSION: "1.20"
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Install dependencies
+        run: go mod download
+
+      - name: Run tests with coverage
+        run: go test -v -coverprofile=coverage.out ./...
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          file: ./coverage.out

README.md

@@ -1,6 +1,7 @@
 # Go Nullable with Generics
 
-[![PkgGoDev](https://pkg.go.dev/badge/github.com/lomsa-dev/gonull)](https://pkg.go.dev/github.com/lomsa-dev/gonull) ![mod-verify](https://github.com/lomsa-dev/gonull/workflows/mod-verify/badge.svg) ![golangci-lint](https://github.com/lomsa-dev/gonull/workflows/golangci-lint/badge.svg) ![staticcheck](https://github.com/lomsa-dev/gonull/workflows/staticcheck/badge.svg) ![gosec](https://github.com/lomsa-dev/gonull/workflows/gosec/badge.svg)
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/lomsa-dev/gonull)](https://pkg.go.dev/github.com/lomsa-dev/gonull) ![mod-verify](https://github.com/lomsa-dev/gonull/workflows/mod-verify/badge.svg) ![golangci-lint](https://github.com/lomsa-dev/gonull/workflows/golangci-lint/badge.svg) ![staticcheck](https://github.com/lomsa-dev/gonull/workflows/staticcheck/badge.svg) ![gosec](https://github.com/lomsa-dev/gonull/workflows/gosec/badge.svg) [![codecov](https://codecov.io/gh/lomsa-dev/gonull/branch/main/graph/badge.svg?token=76089e7b-f137-4459-8eae-4b48007bd0d6)](https://codecov.io/gh/lomsa-dev/gonull)
+
 
 ## Go package simplifies nullable fields handling with Go Generics.