test: run unit tests with DENO_FUTURE=1 (#24400)

This commit adds another test suite that runs all Deno unit tests
with `DENO_FUTURE=1` flag to ensure all APIs are working as
expected, once Deno 2 is released.

---------

Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/unit/test_util.ts b/tests/unit/test_util.ts
index e45a963e9..16ca735ac 100644
--- a/tests/unit/test_util.ts
+++ b/tests/unit/test_util.ts
@@ -25,6 +25,8 @@ export { delay } from "@std/async/delay";
 export { readLines } from "@std/io/read-lines";
 export { parseArgs } from "@std/cli/parse-args";
 
+export const DENO_FUTURE = Deno.env.get("DENO_FUTURE") === "1";
+
 export function pathToAbsoluteFileUrl(path: string): URL {
   path = resolve(path);