chore: import upstream snapshot with attribution

internal/util/wrapper/wrapper_test.go

@@ -0,0 +1,52 @@
+package wrapper
+
+import (
+	"context"
+	"testing"
+
+	"go-micro.dev/v6/metadata"
+)
+
+func TestWrapper(t *testing.T) {
+	testData := []struct {
+		existing  metadata.Metadata
+		headers   metadata.Metadata
+		overwrite bool
+	}{
+		{
+			existing: metadata.Metadata{},
+			headers: metadata.Metadata{
+				"Foo": "bar",
+			},
+			overwrite: true,
+		},
+		{
+			existing: metadata.Metadata{
+				"Foo": "bar",
+			},
+			headers: metadata.Metadata{
+				"Foo": "baz",
+			},
+			overwrite: false,
+		},
+	}
+
+	for _, d := range testData {
+		c := &fromServiceWrapper{
+			headers: d.headers,
+		}
+
+		ctx := metadata.NewContext(context.Background(), d.existing)
+		ctx = c.setHeaders(ctx)
+		md, _ := metadata.FromContext(ctx)
+
+		for k, v := range d.headers {
+			if d.overwrite && md[k] != v {
+				t.Fatalf("Expected %s=%s got %s=%s", k, v, k, md[k])
+			}
+			if !d.overwrite && md[k] != d.existing[k] {
+				t.Fatalf("Expected %s=%s got %s=%s", k, d.existing[k], k, md[k])
+			}
+		}
+	}
+}