ScriptManager (#2021)

* Create ScriptManager class

* Use ScriptManager in Backend

5 files changed, 172 insertions, 144 deletions

diff --git a/.eslintrc.json b/.eslintrc.json
index 1608bc9f..bfc9c3d2 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -186,6 +186,7 @@
                 "ext/js/background/environment.js",
                 "ext/js/background/profile-conditions-util.js",
                 "ext/js/background/request-builder.js",
+                "ext/js/background/script-manager.js",
                 "ext/js/comm/anki.js",
                 "ext/js/comm/clipboard-monitor.js",
                 "ext/js/comm/clipboard-reader.js",
diff --git a/ext/background.html b/ext/background.html
index 6259e519..44027a48 100644
--- a/ext/background.html
+++ b/ext/background.html
@@ -27,6 +27,7 @@
 <script src="/js/background/environment.js"></script>
 <script src="/js/background/profile-conditions-util.js"></script>
 <script src="/js/background/request-builder.js"></script>
+<script src="/js/background/script-manager.js"></script>
 <script src="/js/comm/anki.js"></script>
 <script src="/js/comm/clipboard-monitor.js"></script>
 <script src="/js/comm/clipboard-reader.js"></script>
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index ca2f5f16..f48a87f8 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -31,6 +31,7 @@
  * PermissionsUtil
  * ProfileConditionsUtil
  * RequestBuilder
+ * ScriptManager
  * StringUtil
  * Translator
  * wanakana
@@ -67,6 +68,7 @@ class Backend {
             requestBuilder: this._requestBuilder
         });
         this._optionsUtil = new OptionsUtil();
+        this._scriptManager = new ScriptManager();
 
         this._searchPopupTabId = null;
         this._searchPopupTabCreatePromise = null;
@@ -559,8 +561,10 @@ class Backend {
         return Promise.resolve({tabId, frameId});
     }
 
-    _onApiInjectStylesheet({type, value}, sender) {
-        return this._injectStylesheet(type, value, sender);
+    async _onApiInjectStylesheet({type, value}, sender) {
+        const {frameId, tab} = sender;
+        if (!isObject(tab)) { throw new Error('Invalid tab'); }
+        return await this._scriptManager.injectStylesheet(type, value, tab.id, frameId);
     }
 
     async _onApiGetStylesheetContent({url}) {
@@ -746,7 +750,7 @@ class Backend {
     _onApiDocumentStart(params, sender) {
         const {tab, frameId, url} = sender;
         if (typeof url !== 'string' || typeof tab !== 'object' || tab === null) { return; }
-        this._updateTabAccessibility(url, tab, frameId);
+        this._updateTabAccessibility(url, tab.id, frameId);
     }
 
     async _onApiGetTermFrequencies({termReadingList, dictionaries}) {
@@ -2085,145 +2089,6 @@ class Backend {
         });
     }
 
-    _injectStylesheet(type, value, target) {
-        if (isObject(chrome.tabs) && typeof chrome.tabs.insertCSS === 'function') {
-            return this._injectStylesheetMV2(type, value, target);
-        } else if (isObject(chrome.scripting) && typeof chrome.scripting.insertCSS === 'function') {
-            return this._injectStylesheetMV3(type, value, target);
-        } else {
-            return Promise.reject(new Error('insertCSS function not available'));
-        }
-    }
-
-    _injectStylesheetMV2(type, value, target) {
-        return new Promise((resolve, reject) => {
-            if (!target.tab) {
-                reject(new Error('Invalid tab'));
-                return;
-            }
-
-            const tabId = target.tab.id;
-            const frameId = target.frameId;
-            const details = (
-                type === 'file' ?
-                {
-                    file: value,
-                    runAt: 'document_start',
-                    cssOrigin: 'author',
-                    allFrames: false,
-                    matchAboutBlank: true
-                } :
-                {
-                    code: value,
-                    runAt: 'document_start',
-                    cssOrigin: 'user',
-                    allFrames: false,
-                    matchAboutBlank: true
-                }
-            );
-            if (typeof frameId === 'number') {
-                details.frameId = frameId;
-            }
-
-            chrome.tabs.insertCSS(tabId, details, () => {
-                const e = chrome.runtime.lastError;
-                if (e) {
-                    reject(new Error(e.message));
-                } else {
-                    resolve();
-                }
-            });
-        });
-    }
-
-    _injectStylesheetMV3(type, value, target) {
-        return new Promise((resolve, reject) => {
-            if (!target.tab) {
-                reject(new Error('Invalid tab'));
-                return;
-            }
-
-            const tabId = target.tab.id;
-            const frameId = target.frameId;
-            const details = (
-                type === 'file' ?
-                {origin: chrome.scripting.StyleOrigin.AUTHOR, files: [value]} :
-                {origin: chrome.scripting.StyleOrigin.USER,   css: value}
-            );
-            details.target = {
-                tabId,
-                allFrames: false
-            };
-            if (typeof frameId === 'number') {
-                details.target.frameIds = [frameId];
-            }
-
-            chrome.scripting.insertCSS(details, () => {
-                const e = chrome.runtime.lastError;
-                if (e) {
-                    reject(new Error(e.message));
-                } else {
-                    resolve();
-                }
-            });
-        });
-    }
-
-    _injectScript(file, tabId, frameId) {
-        if (isObject(chrome.tabs) && typeof chrome.tabs.executeScript === 'function') {
-            return this._injectScriptMV2(file, tabId, frameId);
-        } else if (isObject(chrome.scripting) && typeof chrome.scripting.executeScript === 'function') {
-            return this._injectScriptMV3(file, tabId, frameId);
-        } else {
-            return Promise.reject(new Error('executeScript function not available'));
-        }
-    }
-
-    _injectScriptMV2(file, tabId, frameId) {
-        return new Promise((resolve, reject) => {
-            const details = {
-                allFrames: false,
-                frameId,
-                file,
-                matchAboutBlank: true,
-                runAt: 'document_start'
-            };
-            const callback = (results) => {
-                const e = chrome.runtime.lastError;
-                if (e) {
-                    reject(new Error(e.message));
-                } else {
-                    const result = results[0];
-                    resolve({frameId, result});
-                }
-            };
-            chrome.tabs.executeScript(tabId, details, callback);
-        });
-    }
-
-    _injectScriptMV3(file, tabId, frameId) {
-        return new Promise((resolve, reject) => {
-            const details = {
-                files: [file],
-                target: {
-                    allFrames: false,
-                    frameIds: [frameId],
-                    tabId
-                }
-            };
-            const callback = (results) => {
-                const e = chrome.runtime.lastError;
-                if (e) {
-                    reject(new Error(e.message));
-                } else {
-                    const {frameId: frameId2, result} = results[0];
-                    resolve({frameId: frameId2, result});
-                }
-            };
-            chrome.scripting.executeScript(details, callback);
-        });
-    }
-
     _getTabById(tabId) {
         return new Promise((resolve, reject) => {
             chrome.tabs.get(
@@ -2275,7 +2140,7 @@ class Backend {
         }
     }
 
-    async _updateTabAccessibility(url, tab, frameId) {
+    async _updateTabAccessibility(url, tabId, frameId) {
         let file = null;
 
         switch (new URL(url).hostname) {
@@ -2291,7 +2156,7 @@ class Backend {
 
         if (file === null) { return; }
 
-        return await this._injectScript(file, tab.id, frameId);
+        await this._scriptManager.injectScript(file, tabId, frameId);
     }
 
     async _getNormalizedDictionaryDatabaseMedia(targets) {
diff --git a/ext/js/background/script-manager.js b/ext/js/background/script-manager.js
new file mode 100644
index 00000000..a5dbe0d2
--- /dev/null
+++ b/ext/js/background/script-manager.js
@@ -0,0 +1,160 @@
+/*
+ * 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/>.
+ */
+
+/**
+ * This class is used to manage script injection into content tabs.
+ */
+class ScriptManager {
+    /**
+     * Injects a stylesheet into a specific tab and frame.
+     * @param {string} type The type of content to inject; either 'file' or 'code'.
+     * @param {string} content The content to inject.
+     *   If type is 'file', this argument should be a path to a file.
+     *   If type is 'code', this argument should be the CSS content.
+     * @param {number} tabId The id of the tab to inject into.
+     * @param {number} frameId The id of the frame to inject into.
+     * @returns {Promise<void>}
+     */
+    injectStylesheet(type, content, tabId, frameId) {
+        if (isObject(chrome.tabs) && typeof chrome.tabs.insertCSS === 'function') {
+            return this._injectStylesheetMV2(type, content, tabId, frameId);
+        } else if (isObject(chrome.scripting) && typeof chrome.scripting.insertCSS === 'function') {
+            return this._injectStylesheetMV3(type, content, tabId, frameId);
+        } else {
+            return Promise.reject(new Error('Stylesheet injection not supported'));
+        }
+    }
+    /**
+     * Injects a script into a specific tab and frame.
+     * @param {string} file The path to a file to inject.
+     * @param {number} tabId The id of the tab to inject into.
+     * @param {number} frameId The id of the frame to inject into.
+     * @returns {Promise<{frameId: number, result: object}>} The id of the frame and the result of the script injection.
+     */
+    injectScript(file, tabId, frameId) {
+        if (isObject(chrome.tabs) && typeof chrome.tabs.executeScript === 'function') {
+            return this._injectScriptMV2(file, tabId, frameId);
+        } else if (isObject(chrome.scripting) && typeof chrome.scripting.executeScript === 'function') {
+            return this._injectScriptMV3(file, tabId, frameId);
+        } else {
+            return Promise.reject(new Error('Script injection not supported'));
+        }
+    }
+
+    // Private
+
+    _injectStylesheetMV2(type, content, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = (
+                type === 'file' ?
+                {
+                    file: content,
+                    runAt: 'document_start',
+                    cssOrigin: 'author',
+                    allFrames: false,
+                    matchAboutBlank: true
+                } :
+                {
+                    code: content,
+                    runAt: 'document_start',
+                    cssOrigin: 'user',
+                    allFrames: false,
+                    matchAboutBlank: true
+                }
+            );
+            if (typeof frameId === 'number') {
+                details.frameId = frameId;
+            }
+            chrome.tabs.insertCSS(tabId, details, () => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    resolve();
+                }
+            });
+        });
+    }
+
+    _injectStylesheetMV3(type, content, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = (
+                type === 'file' ?
+                {origin: chrome.scripting.StyleOrigin.AUTHOR, files: [content]} :
+                {origin: chrome.scripting.StyleOrigin.USER,   css: content}
+            );
+            details.target = {
+                tabId,
+                allFrames: false
+            };
+            if (typeof frameId === 'number') {
+                details.target.frameIds = [frameId];
+            }
+            chrome.scripting.insertCSS(details, () => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    resolve();
+                }
+            });
+        });
+    }
+
+    _injectScriptMV2(file, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = {
+                allFrames: false,
+                frameId,
+                file,
+                matchAboutBlank: true,
+                runAt: 'document_start'
+            };
+            chrome.tabs.executeScript(tabId, details, (results) => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    const result = results[0];
+                    resolve({frameId, result});
+                }
+            });
+        });
+    }
+
+    _injectScriptMV3(file, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = {
+                files: [file],
+                target: {
+                    allFrames: false,
+                    frameIds: [frameId],
+                    tabId
+                }
+            };
+            chrome.scripting.executeScript(details, (results) => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    const {frameId: frameId2, result} = results[0];
+                    resolve({frameId: frameId2, result});
+                }
+            });
+        });
+    }
+}
diff --git a/ext/sw.js b/ext/sw.js
index 6443c57f..2624a04d 100644
--- a/ext/sw.js
+++ b/ext/sw.js
@@ -24,6 +24,7 @@ self.importScripts(
     '/js/background/environment.js',
     '/js/background/profile-conditions-util.js',
     '/js/background/request-builder.js',
+    '/js/background/script-manager.js',
     '/js/comm/anki.js',
     '/js/comm/clipboard-monitor.js',
     '/js/comm/clipboard-reader.js',