Auto-discover new WPT as they are added

Author: npaun

build/wpt_test.bzl

@@ -9,34 +9,88 @@
 
 load("//:build/wd_test.bzl", "wd_test")
 
-def wpt_test(name, wpt_directory, test_js):
-    test_gen_rule = "{}@_wpt_test_gen".format(name)
-    _wpt_test_gen(
-        name = test_gen_rule,
+def wpt_test(name, wpt_directory, test_config):
+    js_test_gen_rule = "{}@_wpt_js_test_gen".format(name)
+    _wpt_js_test_gen(
+        name = js_test_gen_rule,
         test_name = name,
         wpt_directory = wpt_directory,
-        test_js = test_js,
+        test_config = test_config,
+    )
+
+    wd_test_gen_rule = "{}@_wpt_wd_test_gen".format(name)
+    _wpt_wd_test_gen(
+        name = wd_test_gen_rule,
+        test_name = name,
+        wpt_directory = wpt_directory,
+        test_config = test_config,
+        test_js_generated = js_test_gen_rule,
     )
 
     wd_test(
         name = "{}".format(name),
-        src = test_gen_rule,
+        src = wd_test_gen_rule,
         args = ["--experimental"],
         data = [
             "//src/wpt:wpt-test-harness",
-            test_js,
+            test_config,
+            js_test_gen_rule,
             wpt_directory,
             "//src/workerd/io:trimmed-supported-compatibility-date.txt",
         ],
     )
 
-def _wpt_test_gen_impl(ctx):
+def _wpt_js_test_gen_impl(ctx):
+    src = ctx.actions.declare_file("{}-test.generated.js".format(ctx.attr.test_name))
+    ctx.actions.write(
+        output = src,
+        content = WPT_JS_TEST_TEMPLATE.format(
+            test_config = ctx.file.test_config.basename,
+            cases = generate_external_cases(ctx.attr.wpt_directory.files),
+        ),
+    )
+
+    return DefaultInfo(
+        files = depset([src]),
+    )
+
+def generate_external_cases(files):
+    result = []
+
+    for file in files.to_list():
+        if file.extension == "js":
+            entry = """export const {} = run(config, '{}');""".format(test_case_name(file.basename), file.basename)
+        else:
+            continue
+        result.append(entry)
+
+    return "\n".join(result)
+
+def test_case_name(filename):
+    words = (filename
+        .removesuffix(".js")
+        .removesuffix(".any")
+        .replace(".", "-")
+        .split("-"))
+
+    return words[0] + "".join([word.capitalize() for word in words[1:]])
+
+WPT_JS_TEST_TEMPLATE = """// This file is autogenerated by wpt_test.bzl
+// DO NOT EDIT.
+import {{ run }} from 'wpt:harness';
+import config from '{test_config}';
+
+{cases}
+"""
+
+def _wpt_wd_test_gen_impl(ctx):
     src = ctx.actions.declare_file("{}.wd-test".format(ctx.attr.test_name))
     ctx.actions.write(
         output = src,
-        content = WPT_TEST_TEMPLATE.format(
+        content = WPT_WD_TEST_TEMPLATE.format(
             test_name = ctx.attr.test_name,
-            test_js = wd_relative_path(ctx.file.test_js),
+            test_config = ctx.file.test_config.basename,
+            test_js_generated = wd_relative_path(ctx.file.test_js_generated),
             modules = generate_external_modules(ctx.attr.wpt_directory.files),
         ),
     )
@@ -45,14 +99,15 @@ def _wpt_test_gen_impl(ctx):
         files = depset([src]),
     )
 
-WPT_TEST_TEMPLATE = """
+WPT_WD_TEST_TEMPLATE = """
 using Workerd = import "/workerd/workerd.capnp";
 const unitTests :Workerd.Config = (
   services = [
     ( name = "{test_name}",
       worker = (
         modules = [
-          (name = "worker", esModule = embed "{test_js}"),
+          (name = "worker", esModule = embed "{test_js_generated}"),
+          (name = "{test_config}", esModule = embed "{test_config}"),
           (name = "wpt:harness", esModule = embed "../../../../../workerd/src/wpt/harness.js"),
           {modules}
         ],
@@ -102,14 +157,28 @@ def generate_external_modules(files):
 
     return ",\n".join(result)
 
-_wpt_test_gen = rule(
-    implementation = _wpt_test_gen_impl,
+_wpt_wd_test_gen = rule(
+    implementation = _wpt_wd_test_gen_impl,
+    attrs = {
+        # A string to use as the test name. Used in the wd-test filename and the worker's name
+        "test_name": attr.string(),
+        # A file group representing a directory of wpt tests. All files in the group will be embedded.
+        "wpt_directory": attr.label(),
+        # A JS file containing the test configuration.
+        "test_config": attr.label(allow_single_file = True),
+        # An auto-generated JS file containing the test logic.
+        "test_js_generated": attr.label(allow_single_file = True),
+    },
+)
+
+_wpt_js_test_gen = rule(
+    implementation = _wpt_js_test_gen_impl,
     attrs = {
         # A string to use as the test name. Used in the wd-test filename and the worker's name
         "test_name": attr.string(),
         # A file group representing a directory of wpt tests. All files in the group will be embedded.
         "wpt_directory": attr.label(),
-        # A JS file containing the actual test logic.
-        "test_js": attr.label(allow_single_file = True),
+        # A JS file containing the test configuration.
+        "test_config": attr.label(allow_single_file = True),
     },
 )

src/workerd/api/wpt/BUILD.bazel

@@ -6,6 +6,6 @@ load("//:build/wpt_test.bzl", "wpt_test")
 
 [wpt_test(
     name = file.replace("-test.js", ""),
-    test_js = file,
+    test_config = file,
     wpt_directory = "@wpt//:{}".format(file.replace("-test.js", "")),
 ) for file in glob(["*-test.js"])]