Extract fetch functions to utilities (#629)

* do backend

* other files

* move fetch utils to own file

* remove extra line

* add extra line

* remove unnecessary export

* undo changes to cssStyleApplier

3 files changed, 66 insertions, 85 deletions

diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index b95626f5..af0b3039 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -23,7 +23,7 @@ import {ClipboardReader} from '../comm/clipboard-reader.js';
 import {Mecab} from '../comm/mecab.js';
 import {createApiMap, invokeApiMapHandler} from '../core/api-map.js';
 import {ExtensionError} from '../core/extension-error.js';
-import {readResponseJson} from '../core/json.js';
+import {fetchJson, fetchText} from '../core/fetch-utilities.js';
 import {log} from '../core/logger.js';
 import {clone, deferPromise, isObject, promiseTimeout} from '../core/utilities.js';
 import {isNoteDataValid} from '../data/anki-util.js';
@@ -279,11 +279,11 @@ export class Backend {
             }
 
             /** @type {import('language-transformer').LanguageTransformDescriptor} */
-            const descriptor = await this._fetchJson('/data/language/japanese-transforms.json');
+            const descriptor = await fetchJson('/data/language/japanese-transforms.json');
             this._translator.prepare(descriptor);
 
             await this._optionsUtil.prepare();
-            this._defaultAnkiFieldTemplates = (await this._fetchText('/data/templates/default-anki-field-templates.handlebars')).trim();
+            this._defaultAnkiFieldTemplates = (await fetchText('/data/templates/default-anki-field-templates.handlebars')).trim();
             this._options = await this._optionsUtil.load();
 
             this._applyOptions('background');
@@ -668,7 +668,7 @@ export class Backend {
         if (!url.startsWith('/') || url.startsWith('//') || !url.endsWith('.css')) {
             throw new Error('Invalid URL');
         }
-        return await this._fetchText(url);
+        return await fetchText(url);
     }
 
     /** @type {import('api').ApiHandler<'getEnvironmentInfo'>} */
@@ -683,7 +683,7 @@ export class Backend {
 
     /** @type {import('api').ApiHandler<'getDisplayTemplatesHtml'>} */
     async _onApiGetDisplayTemplatesHtml() {
-        return await this._fetchText('/display-templates.html');
+        return await fetchText('/display-templates.html');
     }
 
     /** @type {import('api').ApiHandler<'getZoom'>} */
@@ -1849,44 +1849,6 @@ export class Backend {
     }
 
     /**
-     * @param {string} url
-     * @returns {Promise<Response>}
-     */
-    async _fetchAsset(url) {
-        const response = await fetch(chrome.runtime.getURL(url), {
-            method: 'GET',
-            mode: 'no-cors',
-            cache: 'default',
-            credentials: 'omit',
-            redirect: 'follow',
-            referrerPolicy: 'no-referrer'
-        });
-        if (!response.ok) {
-            throw new Error(`Failed to fetch ${url}: ${response.status}`);
-        }
-        return response;
-    }
-
-    /**
-     * @param {string} url
-     * @returns {Promise<string>}
-     */
-    async _fetchText(url) {
-        const response = await this._fetchAsset(url);
-        return await response.text();
-    }
-
-    /**
-     * @template [T=unknown]
-     * @param {string} url
-     * @returns {Promise<T>}
-     */
-    async _fetchJson(url) {
-        const response = await this._fetchAsset(url);
-        return await readResponseJson(response);
-    }
-
-    /**
      * @template {import('application').ApiNames} TName
      * @param {import('application').ApiMessage<TName>} message
      */
diff --git a/ext/js/core/fetch-utilities.js b/ext/js/core/fetch-utilities.js
new file mode 100644
index 00000000..074f7c9a
--- /dev/null
+++ b/ext/js/core/fetch-utilities.js
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2024  Yomitan 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/>.
+ */
+
+import {readResponseJson} from './json.js';
+
+/**
+ * @param {string} url
+ * @returns {Promise<Response>}
+ */
+async function fetchAsset(url) {
+    const response = await fetch(chrome.runtime.getURL(url), {
+        method: 'GET',
+        mode: 'no-cors',
+        cache: 'default',
+        credentials: 'omit',
+        redirect: 'follow',
+        referrerPolicy: 'no-referrer'
+    });
+    if (!response.ok) {
+        throw new Error(`Failed to fetch ${url}: ${response.status}`);
+    }
+    return response;
+}
+
+
+/**
+ * @param {string} url
+ * @returns {Promise<string>}
+ */
+export async function fetchText(url) {
+    const response = await fetchAsset(url);
+    return await response.text();
+}
+
+/**
+ * @template [T=unknown]
+ * @param {string} url
+ * @returns {Promise<T>}
+ */
+export async function fetchJson(url) {
+    const response = await fetchAsset(url);
+    return await readResponseJson(response);
+}
\ No newline at end of file
diff --git a/ext/js/data/options-util.js b/ext/js/data/options-util.js
index cbaeb92b..3f3a5ab8 100644
--- a/ext/js/data/options-util.js
+++ b/ext/js/data/options-util.js
@@ -16,8 +16,9 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import {fetchJson, fetchText} from '../core/fetch-utilities.js';
+import {parseJson} from '../core/json.js';
 import {escapeRegExp, isObject} from '../core/utilities.js';
-import {parseJson, readResponseJson} from '../core/json.js';
 import {TemplatePatcher} from '../templates/template-patcher.js';
 import {JsonSchema} from './json-schema.js';
 
@@ -32,7 +33,7 @@ export class OptionsUtil {
     /** */
     async prepare() {
         /** @type {import('ext/json-schema').Schema} */
-        const schema = await this._fetchJson('/data/schemas/options-schema.json');
+        const schema = await fetchJson('/data/schemas/options-schema.json');
         this._optionsSchema = new JsonSchema(schema);
     }
 
@@ -438,7 +439,7 @@ export class OptionsUtil {
             if (fieldTemplates === null) { continue; }
 
             if (patch === null) {
-                const content = await this._fetchText(modificationsUrl);
+                const content = await fetchText(modificationsUrl);
                 if (this._templatePatcher === null) {
                     this._templatePatcher = new TemplatePatcher();
                 }
@@ -450,45 +451,6 @@ export class OptionsUtil {
     }
 
     /**
-     * @param {string} url
-     * @returns {Promise<Response>}
-     */
-    async _fetchGeneric(url) {
-        url = chrome.runtime.getURL(url);
-        const response = await fetch(url, {
-            method: 'GET',
-            mode: 'no-cors',
-            cache: 'default',
-            credentials: 'omit',
-            redirect: 'follow',
-            referrerPolicy: 'no-referrer'
-        });
-        if (!response.ok) {
-            throw new Error(`Failed to fetch ${url}: ${response.status}`);
-        }
-        return response;
-    }
-
-    /**
-     * @param {string} url
-     * @returns {Promise<string>}
-     */
-    async _fetchText(url) {
-        const response = await this._fetchGeneric(url);
-        return await response.text();
-    }
-
-    /**
-     * @template [T=unknown]
-     * @param {string} url
-     * @returns {Promise<T>}
-     */
-    async _fetchJson(url) {
-        const response = await this._fetchGeneric(url);
-        return await readResponseJson(response);
-    }
-
-    /**
      * @param {string} string
      * @returns {number}
      */