Google Docs accessibility refactor (#2023)

* Skip urlRegex if it's used as a filter

* Add getRequiredContentScriptRegistrationPermissions function

* Add a reentrant check to google-docs.js

* Remove script node

* Move forceGoogleDocsHtmlRendering check into google-docs.js

* Replace document-start.js usage with google-docs.js

* Remove documentStart handling

* Add missing parameter descriptions

5 files changed, 62 insertions, 51 deletions

diff --git a/ext/js/accessibility/google-docs.js b/ext/js/accessibility/google-docs.js
index f9ba0f7f..e45743ab 100644
--- a/ext/js/accessibility/google-docs.js
+++ b/ext/js/accessibility/google-docs.js
@@ -15,7 +15,36 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-(() => {
+(async () => {
+    // Reentrant check
+    if (self.googleDocsAccessibilitySetup) { return; }
+    self.googleDocsAccessibilitySetup = true;
+
+    const invokeApi = (action, params) => {
+        return new Promise((resolve, reject) => {
+            chrome.runtime.sendMessage({action, params}, (response) => {
+                void chrome.runtime.lastError;
+                if (typeof response !== 'object' || response === null) {
+                    reject(new Error('Unexpected response'));
+                } else if (typeof response.error !== 'undefined') {
+                    reject(new Error('Invalid response'));
+                } else {
+                    resolve(response.result);
+                }
+            });
+        });
+    };
+
+    const optionsContext = {depth: 0, url: location.href};
+    let options;
+    try {
+        options = await invokeApi('optionsGet', {optionsContext});
+    } catch (e) {
+        return;
+    }
+
+    if (!options.accessibility.forceGoogleDocsHtmlRendering) { return; }
+
     let parent = document.head;
     if (parent === null) {
         parent = document.documentElement;
@@ -24,4 +53,5 @@
     const script = document.createElement('script');
     script.textContent = 'window._docs_force_html_by_ext = true;';
     parent.appendChild(script);
+    parent.removeChild(script);
 })();
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index db43ec57..4e86a23c 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -127,7 +127,6 @@ class Backend {
             ['triggerDatabaseUpdated',       {async: false, contentScript: true,  handler: this._onApiTriggerDatabaseUpdated.bind(this)}],
             ['testMecab',                    {async: true,  contentScript: true,  handler: this._onApiTestMecab.bind(this)}],
             ['textHasJapaneseCharacters',    {async: false, contentScript: true,  handler: this._onApiTextHasJapaneseCharacters.bind(this)}],
-            ['documentStart',                {async: false, contentScript: true,  handler: this._onApiDocumentStart.bind(this)}],
             ['getTermFrequencies',           {async: true,  contentScript: true,  handler: this._onApiGetTermFrequencies.bind(this)}]
         ]);
         this._messageHandlersWithProgress = new Map([
@@ -747,12 +746,6 @@ class Backend {
         return this._japaneseUtil.isStringPartiallyJapanese(text);
     }
 
-    _onApiDocumentStart(params, sender) {
-        const {tab, frameId, url} = sender;
-        if (typeof url !== 'string' || typeof tab !== 'object' || tab === null) { return; }
-        this._updateTabAccessibility(url, tab.id, frameId);
-    }
-
     async _onApiGetTermFrequencies({termReadingList, dictionaries}) {
         return await this._translator.getTermFrequencies(termReadingList, dictionaries);
     }
@@ -2140,25 +2133,6 @@ class Backend {
         }
     }
 
-    async _updateTabAccessibility(url, tabId, frameId) {
-        let file = null;
-
-        switch (new URL(url).hostname) {
-            case 'docs.google.com':
-                {
-                    const optionsContext = {depth: 0, url};
-                    const options = this._getProfileOptions(optionsContext);
-                    if (!options.accessibility.forceGoogleDocsHtmlRendering) { return; }
-                    file = 'js/accessibility/google-docs.js';
-                }
-                break;
-        }
-
-        if (file === null) { return; }
-
-        await this._scriptManager.injectScript(file, tabId, frameId, false, true, 'document_start');
-    }
-
     async _getNormalizedDictionaryDatabaseMedia(targets) {
         const results = await this._dictionaryDatabase.getMedia(targets);
         for (const item of results) {
diff --git a/ext/js/background/script-manager.js b/ext/js/background/script-manager.js
index c6bdc0bb..ba4f8671 100644
--- a/ext/js/background/script-manager.js
+++ b/ext/js/background/script-manager.js
@@ -106,9 +106,9 @@ class ScriptManager {
      * @param {string} id A unique identifier for the registration.
      * @param {object} details The script registration details.
      * @param {boolean} [details.allFrames] Same as `all_frames` in the `content_scripts` manifest key.
-     * @param {string[]} [details.css]
+     * @param {string[]} [details.css] List of CSS paths.
      * @param {string[]} [details.excludeMatches] Same as `exclude_matches` in the `content_scripts` manifest key.
-     * @param {string[]} [details.js]
+     * @param {string[]} [details.js] List of script paths.
      * @param {boolean} [details.matchAboutBlank] Same as `match_about_blank` in the `content_scripts` manifest key.
      * @param {string[]} details.matches Same as `matches` in the `content_scripts` manifest key.
      * @param {string} [details.urlMatches] Regex match pattern to use as a fallback
@@ -181,6 +181,31 @@ class ScriptManager {
         return true;
     }
 
+    /**
+     * Gets the optional permissions required to register a content script.
+     * @returns {string[]} An array of the required permissions, which may be empty.
+     */
+    getRequiredContentScriptRegistrationPermissions() {
+        if (
+            // Firefox
+            (
+                typeof browser === 'object' && browser !== null &&
+                isObject(browser.contentScripts) &&
+                typeof browser.contentScripts.register === 'function'
+            ) ||
+            // Chrome
+            (
+                isObject(chrome.scripting) &&
+                typeof chrome.scripting.registerContentScripts === 'function'
+            )
+        ) {
+            return [];
+        }
+
+        // Fallback
+        return ['webNavigation'];
+    }
+
     // Private
 
     _injectStylesheetMV2(type, content, tabId, frameId, allFrames, matchAboutBlank, runAt) {
@@ -333,8 +358,7 @@ class ScriptManager {
 
     _registerContentScriptFallback(id, details) {
         const {allFrames, css, js, matchAboutBlank, runAt, urlMatches} = details;
-        const urlRegex = new RegExp(urlMatches);
-        const details2 = {allFrames, css, js, matchAboutBlank, runAt, urlRegex};
+        const details2 = {allFrames, css, js, matchAboutBlank, runAt, urlRegex: null};
         let unregister;
         const webNavigationEvent = this._getWebNavigationEvent(runAt);
         if (isObject(webNavigationEvent)) {
@@ -356,6 +380,7 @@ class ScriptManager {
                 chrome.tabs.onUpdated.addListener(onTabUpdated, extraParameters);
             } catch (e) {
                 // Chrome
+                details2.urlRegex = new RegExp(urlMatches);
                 chrome.tabs.onUpdated.addListener(onTabUpdated);
             }
             unregister = () => chrome.tabs.onUpdated.removeListener(onTabUpdated);
@@ -378,7 +403,7 @@ class ScriptManager {
 
     async _injectContentScript(isWebNavigation, details, status, url, tabId, frameId) {
         const {urlRegex} = details;
-        if (typeof urlRegex !== 'undefined' && !urlRegex.test(url)) { return; }
+        if (urlRegex !== null && !urlRegex.test(url)) { return; }
 
         let {allFrames, css, js, matchAboutBlank, runAt} = details;
 
diff --git a/ext/js/document-start.js b/ext/js/document-start.js
deleted file mode 100644
index de1c2403..00000000
--- a/ext/js/document-start.js
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (C) 2021  Yomichan Authors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-chrome.runtime.sendMessage({action: 'documentStart'}, () => void chrome.runtime.lastError);
diff --git a/ext/manifest.json b/ext/manifest.json
index cd75e216..422d296e 100644
--- a/ext/manifest.json
+++ b/ext/manifest.json
@@ -72,7 +72,7 @@
             "match_about_blank": true,
             "all_frames": true,
             "js": [
-                "js/document-start.js"
+                "js/accessibility/google-docs.js"
             ]
         }
     ],