[Import Maps] WPT: Check parsed import maps' scopes

Before this CL, only `imports` parts of import maps were tested.

Chromium side:
- This CL makes ImportMap::ToString() to output the whole import map,
  rather than only the `imports` value.
- This CL removes white spaces for pretty printing, to simplify
  the logic.

WPT side:
- This CL checks the whole import maps in `jest-test-helper.js`.
- Reflect the upstream changes in
  WICG/import-maps#190 to
  `builtin-support.tentative/imported/resources/parsing-scope-keys.js`.

Test expectation changes:
- This CL exposes new test failures in
  `parsing-scope-keys.tentative.html` on Chromium
  due to the spec-inconformant behavior of Chromium's URL parser.
- Other test expectation changes are just converting
  `x` to `{imports: x, scopes: {}}`.

Bug: 990561, 927181
Change-Id: Ic6a0171298636170d2fd96db2ac1a8d60e3ff345
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863854
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706790}

import-maps/builtin-support.tentative/imported/resources/parsing-scope-keys.js

@@ -62,14 +62,14 @@ describe('Relative URL scope keys', () => {
 });
 
 describe('Absolute URL scope keys', () => {
-  it('should only accept absolute URL scope keys with fetch schemes', () => {
+  it('should accept all absolute URL scope keys, with or without fetch schemes', () => {
     expectScopes(
       [
         'about:good',
         'blob:good',
         'data:good',
         'file:///good',
-        'filesystem:good',
+        'filesystem:http://example.com/good/',
         'http://good/',
         'https://good/',
         'ftp://good/',
@@ -84,17 +84,16 @@ describe('Absolute URL scope keys', () => {
         'blob:good',
         'data:good',
         'file:///good',
-        'filesystem:good',
+        'filesystem:http://example.com/good/',
         'http://good/',
         'https://good/',
-        'ftp://good/'
+        'ftp://good/',
+        'import:bad',
+        'mailto:bad',
+        'javascript:bad',
+        'wss://ba/'
       ],
-      [
-        'Invalid scope "import:bad". Scope URLs must have a fetch scheme.',
-        'Invalid scope "mailto:bad". Scope URLs must have a fetch scheme.',
-        'Invalid scope "javascript:bad". Scope URLs must have a fetch scheme.',
-        'Invalid scope "wss://ba/". Scope URLs must have a fetch scheme.'
-      ]
+      []
     );
   });
 

import-maps/resources/jest-test-helper.js

@@ -15,6 +15,22 @@ function require(name) {
   }, exports);
 }
 
+// Sort keys and then stringify for comparison.
+function stringifyImportMap(importMap) {
+  function getKeys(m) {
+    if (typeof m !== 'object')
+      return [];
+
+    let keys = [];
+    for (const key in m) {
+      keys.push(key);
+      keys = keys.concat(getKeys(m[key]));
+    }
+    return keys;
+  }
+  return JSON.stringify(importMap, getKeys(importMap).sort());
+}
+
 function expect(v) {
   return {
     toMatchURL: expected => assert_equals(v, expected),
@@ -34,10 +50,8 @@ function expect(v) {
         const actualParsedImportMap = JSON.parse(
             internals.getParsedImportMap(v.contentDocument));
         assert_equals(
-          JSON.stringify(actualParsedImportMap,
-                         Object.keys(actualParsedImportMap).sort()),
-          JSON.stringify(expected.imports,
-                         Object.keys(expected.imports).sort())
+          stringifyImportMap(actualParsedImportMap),
+          stringifyImportMap(expected)
         );
       } else {
         assert_object_equals(v, expected);