Tests: improve diffing for values of different types

Close gh-5454

Co-authored-by: Richard Gibson <richard.gibson@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/test/runner/listeners.js b/test/runner/listeners.js
index cca2bbd62..61a98e7ce 100644
--- a/test/runner/listeners.js
+++ b/test/runner/listeners.js
@@ -53,6 +53,17 @@
 					return nu;
 				}
 			}
+
+			// Serialize Symbols as string representations so they are
+			// sent over the wire after being stringified.
+			if ( typeof value === "symbol" ) {
+
+				// We can *describe* unique symbols, but note that their identity
+				// (e.g., `Symbol() !== Symbol()`) is lost
+				var ctor = Symbol.keyFor( value ) !== undefined ? "Symbol.for" : "Symbol";
+				return ctor + "(" + JSON.stringify( value.description ) + ")";
+			}
+
 			return value;
 		}
 		return derez( object );