[URLPattern] implement URLPattern.generate() in Blink

This CL exposes the new Web API, `URLPattern.generate()`, discussed in
the DesignDoc [1]. The new experimental `URLPatternGenerate` flag is
needed to enable this feature. This CL also adds WPTs for this feature.

[1] https://docs.google.com/document/d/1hOG2SzMVab0fBJrV8J8w3wSWsbGZxDLyvjdhDu8WsT0/

Bug: 414682820
Change-Id: Id1df99bede7782dfdee605c2b998150422158f4b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6582245
Commit-Queue: Takashi Nakayama <[email protected]>
Reviewed-by: Domenic Denicola <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1465737}

Author: azaika

urlpattern/resources/urlpattern-generate-test-data.json

@@ -0,0 +1,116 @@
+[
+  {
+    "pattern": { "pathname": "/foo" },
+    "component": "invalid",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo" },
+    "component": "pathname",
+    "groups": {},
+    "expected": "/foo"
+  },
+  {
+    "pattern": { "pathname": "/:foo" },
+    "component": "pathname",
+    "groups": { "foo": "bar" },
+    "expected": "/bar"
+  },
+  {
+    "pattern": { "pathname": "/:foo" },
+    "component": "pathname",
+    "groups": { "foo": "🍅" },
+    "expected": "/%F0%9F%8D%85"
+  },
+  {
+    "pattern": { "hostname": "{:foo}.example.com" },
+    "component": "hostname",
+    "groups": { "foo": "🍅" },
+    "expected": "xn--fi8h.example.com"
+  },
+  {
+    "pattern": { "pathname": "/:foo" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar" },
+    "component": "pathname",
+    "groups": { "bar": "baz" },
+    "expected": "/foo/baz"
+  },
+  {
+    "pattern": { "pathname": "/foo:bar" },
+    "component": "pathname",
+    "groups": { "bar": "baz" },
+    "expected": "/foobaz"
+  },
+  {
+    "pattern": { "pathname": "/:foo/:bar" },
+    "component": "pathname",
+    "groups": { "foo": "baz", "bar": "qux" },
+    "expected": "/baz/qux"
+  },
+  {
+    "pattern": "https://example.com/:foo",
+    "component": "pathname",
+    "groups": { "foo": " " },
+    "expected": "/%20"
+  },
+  {
+    "pattern": "original-scheme://example.com/:foo",
+    "component": "pathname",
+    "groups": { "foo": " " },
+    "expected": "/ "
+  },
+  {
+    "pattern": { "pathname": "/:foo" },
+    "component": "pathname",
+    "groups": { "foo": "bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "*" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/{foo}+" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/{foo}?" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/{foo}*" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/(regexp)" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/([^\\/]+?)" },
+    "component": "pathname",
+    "groups": {},
+    "expected": null
+  },
+  {
+    "pattern": { "port": "([^\\:]+?)" },
+    "component": "port",
+    "groups": {},
+    "expected": null
+  }
+]

urlpattern/urlpattern-generate.tentative.any.js

@@ -0,0 +1,26 @@
+// META: global=window,worker
+
+function runTests(data) {
+  for (let entry of data) {
+    test(function () {
+      const pattern = new URLPattern(entry.pattern);
+
+      if (entry.expected === null) {
+        assert_throws_js(TypeError, _ => pattern.generate(entry.component, entry.groups),
+                         'generate() should fail with TypeError');
+        return;
+      }
+
+      const result = pattern.generate(entry.component, entry.groups);
+      assert_equals(result, entry.expected);
+    }, `Pattern: ${JSON.stringify(entry.pattern)} ` +
+    `Component: ${entry.component} ` +
+    `Groups: ${JSON.stringify(entry.groups)}`);
+  }
+}
+
+promise_test(async function () {
+  const response = await fetch('resources/urlpattern-generate-test-data.json');
+  const data = await response.json();
+  runTests(data);
+}, 'Loading data...');