fix(errors): correct error message for invalid JSON pointer start (#118)

Signed-off-by: Oleksandr Redko <oleksandr.red+github@gmail.com>

Author: alexandear

errors.go

@@ -16,7 +16,7 @@ const (
 	ErrPointer pointerError = "JSON pointer error"
 
 	// ErrInvalidStart states that a JSON pointer must start with a separator ("/").
-	ErrInvalidStart pointerError = `JSON pointer must be empty or start with a "` + pointerSeparator
+	ErrInvalidStart pointerError = `JSON pointer must be empty or start with a "` + pointerSeparator + `"`
 
 	// ErrUnsupportedValueType indicates that a value of the wrong type is being set.
 	ErrUnsupportedValueType pointerError = "only structs, pointers, maps and slices are supported for setting values"

pointer_test.go

@@ -444,6 +444,8 @@ func TestOtherThings(t *testing.T) {
 	t.Run("single string pointer should be valid", func(t *testing.T) {
 		_, err := New("abc")
 		require.Error(t, err)
+		assert.EqualError(t, err, `JSON pointer must be empty or start with a "/"
+JSON pointer error`)
 	})
 
 	t.Run("empty string pointer should be valid", func(t *testing.T) {