Log update (#701)

* Don't export Logger

* Rename logger.js to log.js

* Move helper function

* Update extension name configuration

* Simplify docs

* Move issue URL to a field

* Simplify context

* Remove optional params that are never used

* Configure backend

* Update eslint

* Simplify

* Rename function

* Simplify _api reference

* Simplify docs

* Remove unused log levels (except 'log')

* Add log function

* Rename for more clear intent

* Use log.log

1 files changed, 149 insertions, 0 deletions

diff --git a/ext/js/core/log.js b/ext/js/core/log.js
new file mode 100644
index 00000000..8401cc2b
--- /dev/null
+++ b/ext/js/core/log.js
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2023-2024  Yomitan Authors
+ * Copyright (C) 2019-2022  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/>.
+ */
+
+import {EventDispatcher} from './event-dispatcher.js';
+import {ExtensionError} from './extension-error.js';
+
+/**
+ * This class handles logging of messages to the console and triggering an event for log calls.
+ * @augments EventDispatcher<import('log').Events>
+ */
+class Logger extends EventDispatcher {
+    constructor() {
+        super();
+        /** @type {string} */
+        this._extensionName = 'Extension';
+        /** @type {?string} */
+        this._issueUrl = 'https://github.com/themoeway/yomitan/issues';
+    }
+
+    /**
+     * @param {string} extensionName
+     */
+    configure(extensionName) {
+        this._extensionName = extensionName;
+    }
+
+    /**
+     * @param {unknown} message
+     * @param {...unknown} optionalParams
+     */
+    log(message, ...optionalParams) {
+        /* eslint-disable no-console */
+        console.log(message, ...optionalParams);
+        /* eslint-enable no-console */
+    }
+
+    /**
+     * Logs a warning.
+     * @param {unknown} error The error to log. This is typically an `Error` or `Error`-like object.
+     */
+    warn(error) {
+        this.logGenericError(error, 'warn');
+    }
+
+    /**
+     * Logs an error.
+     * @param {unknown} error The error to log. This is typically an `Error` or `Error`-like object.
+     */
+    error(error) {
+        this.logGenericError(error, 'error');
+    }
+
+    /**
+     * Logs a generic error.
+     * @param {unknown} error The error to log. This is typically an `Error` or `Error`-like object.
+     * @param {import('log').LogLevel} level
+     * @param {import('log').LogContext} [context]
+     */
+    logGenericError(error, level, context) {
+        if (typeof context === 'undefined') {
+            context = {url: location.href};
+        }
+
+        let errorString;
+        try {
+            if (typeof error === 'string') {
+                errorString = error;
+            } else {
+                errorString = (
+                    typeof error === 'object' && error !== null ?
+                    // eslint-disable-next-line @typescript-eslint/no-base-to-string
+                    error.toString() :
+                    `${error}`
+                );
+                if (/^\[object \w+\]$/.test(errorString)) {
+                    errorString = JSON.stringify(error);
+                }
+            }
+        } catch (e) {
+            errorString = `${error}`;
+        }
+
+        let errorStack;
+        try {
+            errorStack = (
+                error instanceof Error ?
+                (typeof error.stack === 'string' ? error.stack.trimEnd() : '') :
+                ''
+            );
+        } catch (e) {
+            errorStack = '';
+        }
+
+        let errorData;
+        try {
+            if (error instanceof ExtensionError) {
+                errorData = error.data;
+            }
+        } catch (e) {
+            // NOP
+        }
+
+        if (errorStack.startsWith(errorString)) {
+            errorString = errorStack;
+        } else if (errorStack.length > 0) {
+            errorString += `\n${errorStack}`;
+        }
+
+        let message = `${this._extensionName} has encountered a problem.`;
+        message += `\nOriginating URL: ${context.url}\n`;
+        message += errorString;
+        if (typeof errorData !== 'undefined') {
+            message += `\nData: ${JSON.stringify(errorData, null, 4)}`;
+        }
+        if (this._issueUrl !== null) {
+            message += `\n\nIssues can be reported at ${this._issueUrl}`;
+        }
+
+        /* eslint-disable no-console */
+        switch (level) {
+            case 'log': console.log(message); break;
+            case 'warn': console.warn(message); break;
+            case 'error': console.error(message); break;
+        }
+        /* eslint-enable no-console */
+
+        this.trigger('logGenericError', {error, level, context});
+    }
+}
+
+/**
+ * This object is the default logger used by the runtime.
+ */
+export const log = new Logger();