test: add snapshot and test case for URL escaping with backslashes (#1621)

Author: ruchira-net

test/runtime/__snapshots__/getUrl.test.js.snap

@@ -85,3 +85,5 @@ exports[`escape should escape url 41`] = `""image other.png#hash""`;
 exports[`escape should escape url 42`] = `""image other.png#hash""`;
 
 exports[`escape should escape url 43`] = `""image other.png#hash""`;
+
+exports[`escape should escape url 44`] = `"http://url/path\\/"`;

test/runtime/getUrl.test.js

@@ -127,5 +127,6 @@ describe("escape", () => {
         { hash: "#hash", needQuotes: true },
       ),
     ).toMatchSnapshot();
+    expect(getUrl("http://url/path\\/")).toMatchSnapshot();
   });
 });