variable Deno.test
Register a test which will be run when `deno test` is used on the command
line and the containing module looks like a test module.
`fn` can be async if required.
```ts
import { assertEquals } from "jsr:@std/assert";
Deno.test({
name: "example test",
fn() {
assertEquals("world", "world");
},
});
Deno.test({
name: "example ignored test",
ignore: Deno.build.os === "windows",
fn() {
// This test is ignored only on Windows machines
},
});
Deno.test({
name: "example async test",
async fn() {
const decoder = new TextDecoder("utf-8");
const data = await Deno.readFile("hello_world.txt");
assertEquals(decoder.decode(data), "Hello world");
}
});
```