heal: Refactor heal command. (#2901)

- return errors for heal operation through rpc replies.
  - implement rotating wheel for healing status.

Fixes #2491

cmd/utils_test.go

@@ -124,6 +124,48 @@ func TestMaxObjectSize(t *testing.T) {
 	}
 }
 
+// Test urlPathSplit.
+func TestURLPathSplit(t *testing.T) {
+	type test struct {
+		urlPath    string
+		bucketName string
+		prefixName string
+	}
+
+	testCases := []test{
+		{
+			urlPath:    "/b/c/",
+			bucketName: "b",
+			prefixName: "c/",
+		},
+		{
+			urlPath:    "c/aa",
+			bucketName: "c",
+			prefixName: "aa",
+		},
+		{
+			urlPath:    "",
+			bucketName: "",
+			prefixName: "",
+		},
+		{
+			urlPath:    "/b",
+			bucketName: "b",
+			prefixName: "",
+		},
+	}
+
+	for i, testCase := range testCases {
+		bucketName, prefixName := urlPathSplit(testCase.urlPath)
+		if bucketName != testCase.bucketName {
+			t.Errorf("Tets %d: Expected %s, %s", i+1, testCase.bucketName, bucketName)
+		}
+		if prefixName != testCase.prefixName {
+			t.Errorf("Tets %d: Expected %s, %s", i+1, testCase.bucketName, bucketName)
+		}
+	}
+}
+
 // Tests minimum allowed part size.
 func TestMinAllowedPartSize(t *testing.T) {
 	sizes := []struct {