From fd0a733d3a7e4cfee8f0537dcdccb36e5175d657 Mon Sep 17 00:00:00 2001
From: Hiroshige Hayashizaki <hiroshige@chromium.org>
Date: Tue, 3 Dec 2019 16:42:04 -0800
Subject: [PATCH] [Import Maps] Remove Blink internals dependency from
 WPT/import-maps/common

Quick draft.

Note:

https://web-platform-tests.org/writing-tests/testdriver-extension-tutorial.html
provides two methods, `testdriver-vendor.js` and `testdriver-extra.js`.
I'm not sure which method to use, but in this CL
I used `testdriver-vendor.js` method, because

- It was easier to implement.
- So far the API is expected only for testing and not needed to be
  exposed for automation.

This CL contradicts with:
https://web-platform-tests.org/writing-tests/testdriver.html
> NB: presently, testdriver.js only works in the top-level
> test browsing context (and not therefore in any frame or
> window opened from it).
because `test_driver` is accessed from inside `<iframe>`s
in this CL.
Perhaps this is OK in this case, as the `resolve_module_specifier`
implementation works inside <iframe>s, while other `test_driver`
method might stop working there.

Bug: 1026809, https://github.com/WICG/import-maps/issues/170
Change-Id: I8684ec544382e3036b9885e09f0c3a4d97208da5
---
 .../common/resources/common-test-helper.js    | 41 +++++++++++--------
 lint.whitelist                                |  1 -
 resources/testdriver.js                       | 29 +++++++++++++
 3 files changed, 54 insertions(+), 17 deletions(-)

diff --git a/import-maps/common/resources/common-test-helper.js b/import-maps/common/resources/common-test-helper.js
index 002c4b51fd06a6..e4f50342b7a61a 100644
--- a/import-maps/common/resources/common-test-helper.js
+++ b/import-maps/common/resources/common-test-helper.js
@@ -16,7 +16,11 @@ function parse(importMap, importMapBaseURL) {
       },
       {once: true});
 
+    const host = location.origin;
+
     const testHTML = `
+      <script src="${host}/resources/testdriver.js"></script>
+      <script src="${host}/resources/testdriver-vendor.js"></script>
       <script>
       // Handle errors around fetching, parsing and registering import maps.
       let registrationResult;
@@ -39,20 +43,23 @@ function parse(importMap, importMapBaseURL) {
 
       // Handle specifier resolution requests from the parent frame.
       window.addEventListener('message', event => {
-        try {
-          // URL resolution is tested using Chromium's internals.
-          // TODO(hiroshige): Remove the Chromium-specific dependency.
-          const result = internals.resolveModuleSpecifier(
-              event.data.specifier,
-              event.data.baseURL,
-              document);
-          parent.postMessage({type: 'ResolutionSuccess', result: result}, '*');
-        } catch (e) {
-          // We post error names instead of error objects themselves and
-          // re-create error objects later, to avoid issues around serializing
-          // error objects which is a quite new feature.
-          parent.postMessage({type: 'ResolutionFailure', result: e.name}, '*');
-        }
+        // Override the base URL.
+        const base = document.createElement('base');
+        base.setAttribute('href', event.data.baseURL);
+        document.head.insertBefore(base, document.head.firstChild);
+
+        test_driver.resolve_module_specifier(event.data.specifier)
+          .then(result => {
+              parent.postMessage(
+                  {type: 'ResolutionSuccess', result: result}, '*');
+            })
+          .catch(e => {
+              // We post error names instead of error objects themselves and
+              // re-create error objects later, to avoid issues around
+              // serializing error objects which is a quite new feature.
+              parent.postMessage(
+                  {type: 'ResolutionFailure', result: e.name}, '*');
+            });
       });
       </script>
       <script type="importmap" onerror="onScriptError(event)">
@@ -61,9 +68,11 @@ function parse(importMap, importMapBaseURL) {
     `;
 
     if (new URL(importMapBaseURL).protocol === 'data:') {
-      iframe.src = 'data:text/html;base64,' + btoa(testHTML);
+      iframe.src =
+          `data:text/html;base64,<head></head>${btoa(testHTML)}`;
     } else {
-      iframe.srcdoc = `<base href="${importMapBaseURL}">` + testHTML;
+      iframe.srcdoc =
+          `<head><base href="${importMapBaseURL}"></head>${testHTML}`;
     }
 
     document.body.appendChild(iframe);
diff --git a/lint.whitelist b/lint.whitelist
index a1b3f63650cb91..4f2ef9c005b6a1 100644
--- a/lint.whitelist
+++ b/lint.whitelist
@@ -677,7 +677,6 @@ MISSING-LINK: css/filter-effects/*.any.js
 # Tests that use WebKit/Blink testing APIs
 LAYOUTTESTS APIS: css/css-regions/interactivity/*
 LAYOUTTESTS APIS: import-maps/resources/jest-test-helper.js
-LAYOUTTESTS APIS: import-maps/common/resources/common-test-helper.js
 LAYOUTTESTS APIS: resources/chromium/generic_sensor_mocks.js
 LAYOUTTESTS APIS: resources/chromium/nfc-mock.js
 LAYOUTTESTS APIS: resources/chromium/webxr-test.js
diff --git a/resources/testdriver.js b/resources/testdriver.js
index 22d5ead72267a3..b34dfc56d9d8e8 100644
--- a/resources/testdriver.js
+++ b/resources/testdriver.js
@@ -355,6 +355,21 @@
         set_user_verified: function(authenticator_id, uv) {
             return window.test_driver_internal.set_user_verified(authenticator_id, uv);
         },
+
+        /**
+         * Resolves the given specifier, possibly with import maps.
+         * https://wicg.github.io/import-maps/#resolve-a-module-specifier
+         *
+         * @param {String} specifier - the specifier to be resolved.
+         *
+         * @returns {Promise} resolved with serialization of the resulting URL
+         *                    as a {String},
+         *                    or rejected on specifier resolution failures.
+         */
+        resolve_module_specifier: function(specifier) {
+            return window.test_driver_internal.resolve_module_specifier(
+                specifier);
+        },
     };
 
     window.test_driver_internal = {
@@ -569,5 +584,19 @@
         set_user_verified: function(authenticator_id, uv) {
             return Promise.reject(new Error("unimplemented"));
         },
+
+        /**
+         * Resolves the given specifier, possibly with import maps.
+         * https://wicg.github.io/import-maps/#resolve-a-module-specifier
+         *
+         * @param {String} specifier - the specifier to be resolved.
+         *
+         * @returns {Promise} resolved with serialization of the resulting URL
+         *                    as a {String},
+         *                    or rejected on specifier resolution failures.
+         */
+        resolve_module_specifier: function(specifier) {
+            return Promise.reject(new Error("unimplemented"));
+        },
     };
 })();