fixup! copy reporter changes from jquery

Author: timmywil

tests/runner/.eslintrc.json

@@ -24,7 +24,8 @@
 				"browser": true
 			},
 			"globals": {
-				"QUnit": false
+				"QUnit": false,
+				"Symbol": false
 			},
 			"parserOptions": {
 				"ecmaVersion": 5,

tests/runner/listeners.js

@@ -1,5 +1,4 @@
 ( function() {
-
 	"use strict";
 
 	// Get the report ID from the URL.
@@ -53,6 +52,14 @@
 					return nu;
 				}
 			}
+
+			// Serialize Symbols as string representations so they are
+			// sent over the wire after being stringified.
+			if ( typeof value === "symbol" ) {
+				var ctor = Symbol.keyFor( value ) !== undefined ? "Symbol.for" : "Symbol";
+				return ctor + "(" + JSON.stringify( value.description ) + ")";
+			}
+
 			return value;
 		}
 		return derez( object );
@@ -99,5 +106,4 @@
 			};
 		} );
 	} );
-
 } )();

tests/runner/reporter.js

@@ -3,11 +3,14 @@ import { getBrowserString } from "./lib/getBrowserString.js";
 import { prettyMs } from "./lib/prettyMs.js";
 import * as Diff from "diff";
 
-const rdquo = /"/g;
+function serializeForDiff( value ) {
 
-function quoteWrap( value ) {
+	// Use naive serialization for everything except types with confusable values
 	if ( typeof value === "string" ) {
-		return `"${ value.replace( rdquo, "\\\"" ) }"`;
+		return JSON.stringify( value );
+	}
+	if ( typeof value === "bigint" ) {
+		return `${ value }n`;
 	}
 	return `${ value }`;
 }
@@ -76,12 +79,12 @@ export function reportTest( test, reportId, { browser, headless } ) {
 
 					// Diff the characters of strings
 					diff = Diff.diffChars( error.expected, error.actual );
-				} else if ( error.expected != null && error.actual != null ) {
+				} else {
 
 					// Diff everything else as words
 					diff = Diff.diffWords(
-						quoteWrap( error.expected ),
-						quoteWrap( error.actual )
+						serializeForDiff( error.expected ),
+						serializeForDiff( error.actual )
 					);
 				}