fix: handle invalid date objects in jsonify stringify (#2851)

## Summary
- Handles the case when `Date.toISOString()` throws for invalid dates by
catching the error and serializing as `"Invalid Date"`
- Round-trips correctly: `new Date("Invalid Date")` serializes to
`["Date","Invalid Date"]` and deserializes back to an invalid `Date`
object
- Adds test case and snapshot for invalid `Date`

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

Author: dahlia

packages/fresh/src/jsonify/__snapshots__/round_trip_test.ts.snap

@@ -44,6 +44,8 @@ snapshot[`round trip - URL {\\n  href: 'https://fresh.deno.dev/',\\n  origin: 'h
 
 snapshot[`round trip - 1990-05-31T00:00:00.000Z 1`] = `'[["Date","1990-05-31T00:00:00.000Z"]]'`;
 
+snapshot[`round trip - Invalid Date 1`] = `'[["Date","Invalid Date"]]'`;
+
 snapshot[`round trip - Map(2) { 1 => null, undefined => -2 } 1`] = `'[["Map",[1,-2,-1,2]],1,-2]'`;
 
 snapshot[`round trip - Set(5) { 1, 2, null, -2, NaN } 1`] = `'[["Set",[1,2,-2,3,-3]],1,2,-2]'`;

packages/fresh/src/jsonify/round_trip_test.ts

@@ -34,6 +34,7 @@ const TESTS = [
   new Uint8Array([1, 2, 3]),
   new URL("https://fresh.deno.dev"),
   new Date("1990-05-31"),
+  new Date("Invalid Date"),
   new Map([[1, null], [undefined, -2]]),
   new Set([1, 2, null, -2, NaN]),
   [1, , 3],

packages/fresh/src/jsonify/stringify.ts

@@ -108,7 +108,13 @@ function serializeInner(
     if (value instanceof URL) {
       str += `["URL","${value.href}"]`;
     } else if (value instanceof Date) {
-      str += `["Date","${value.toISOString()}"]`;
+      let iso: string;
+      try {
+        iso = value.toISOString();
+      } catch {
+        iso = "Invalid Date";
+      }
+      str += `["Date","${iso}"]`;
     } else if (value instanceof RegExp) {
       str += `["RegExp",${JSON.stringify(value.source)}, "${value.flags}"]`;
     } else if (value instanceof Uint8Array) {