tests: add web platform test runner (#8990)

Co-authored-by: Kitson Kelly <me@kitsonkelly.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/cli/tests/WPT.md b/cli/tests/WPT.md
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+## Web Platform Tests
+
+The WPT are test suites for Web platform specs, like Fetch, WHATWG Streams, or
+console. Deno is able to run most `.any.js` and `.window.js` web platform tests.
+
+This directory contains a `wpt.json` file that is used to configure our WPT test
+runner. You can use this json file to set which WPT suites to run, and which
+tests we expect to fail (due to bugs or because they are out of scope for Deno).
+
+To include a new test file to run, add it to the array of test files for the
+corresponding suite. For example we want to enable
+`streams/readable-streams/general`. The file would then look like this:
+
+```json
+{
+  "streams": ["readable-streams/general"]
+}
+```
+
+If you need more configurability over which test cases in a test file of a suite
+to run, you can use the object representation. In the example below, we
+configure `streams/readable-streams/general` to expect
+`ReadableStream can't be constructed with an invalid type` to fail.
+
+```json
+{
+  "streams": [
+    {
+      "name": "readable-streams/general",
+      "expectFail": ["ReadableStream can't be constructed with an invalid type"]
+    }
+  ]
+}
+```