Add coverage + codecov

.github/workflows/go.yml

@@ -37,9 +37,16 @@ jobs:
       run: mise run test
 
     - name: Verify golden files
-      if: env.GO_NOT_LATEST == 'false'
+      if: env.MISE_ENV == 'stable'
       run: make diff-testdata
 
+    - name: Generate coverage
+      run: mise run coverage
+    - name: Upload to CodeCov
+      uses: codecov/codecov-action@v5
+      with:
+        files: ./cover.unsafe.out,./cover.safe.out
+
   lint:
     name: lint
     runs-on: ubuntu-latest

.mise.toml

@@ -10,6 +10,10 @@ run = "go build ./..."
 description = "Run Go tests"
 run = "go test ./..."
 
+[tasks.cover]
+description = "Run Go tests with coverage"
+run = "go test -coverprofile cover.out ./..."
+
 [tasks.lint]
 description = "Run golangci-lint"
 run = "golangci-lint run ./..."

codecov.yml

@@ -0,0 +1,4 @@
+comment: false
+ignore:
+  # test runner logic for integration tests against stdlib
+  - 'internal/cmptest/*.go'