1 files changed, 71 insertions, 0 deletions
diff --git a/go/tools/bzltestutil/lcov_test.go b/go/tools/bzltestutil/lcov_test.go
new file mode 100644
index 00000000..3dc595b6
--- /dev/null
+++ b/go/tools/bzltestutil/lcov_test.go
@@ -0,0 +1,71 @@
+package bzltestutil
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestConvertCoverToLcov(t *testing.T) {
+	var tests = []struct {
+		name         string
+		goCover      string
+		expectedLcov string
+	}{
+		{
+			"empty",
+			"",
+			"",
+		},
+		{
+			"mode only",
+			"mode: set\n",
+			"",
+		},
+		{
+			"single file",
+			`mode: count
+file.go:0.4,2.10 0 0
+`,
+			`SF:file.go
+DA:0,0
+DA:1,0
+DA:2,0
+LH:0
+LF:3
+end_of_record
+`,
+		},
+		{
+			"narrow ranges",
+			`mode: atomic
+path/to/pkg/file.go:0.1,0.2 5 1
+path/to/pkg/file2.go:1.2,1.2 4 2
+`,
+			`SF:path/to/pkg/file.go
+DA:0,1
+LH:1
+LF:1
+end_of_record
+SF:path/to/pkg/file2.go
+DA:1,2
+LH:1
+LF:1
+end_of_record
+`,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			in := strings.NewReader(tt.goCover)
+			var out strings.Builder
+			err := convertCoverToLcov(in, &out)
+			if err != nil {
+				t.Errorf("convertCoverToLcov returned unexpected error: %+v", err)
+			}
+			actualLcov := out.String()
+			if actualLcov != tt.expectedLcov {
+				t.Errorf("covertCoverToLcov returned:\n%q\n, expected:\n%q\n", actualLcov, tt.expectedLcov)
+			}
+		})
+	}
+}