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1 files changed, 67 insertions, 0 deletions

diff --git a/shared/logger/src/base.ts b/shared/logger/src/base.ts
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+++ b/shared/logger/src/base.ts
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+import type { Level, Logger } from './types';
+
+export abstract class BaseLogger<Args extends unknown[] = unknown[]>
+    implements Logger<Args>
+{
+    constructor(protected readonly name: string) {}
+
+    /**
+     * Log a debug level message.
+     * Appropriate for verbose logging that explains steps/details of the inner state of
+     * a code unit.
+     *
+     * Example uses include in a size-constrain datastructure, logging when the size
+     * exceeds the threshold and elements are removed, or in a virtual scrolling
+     * component logging when a scroll event causes a new page of elements to be loaded.
+     *
+     * @param args Arguments to log (same as console.debug)
+     * @return empty string (for use in brackets {} in svelte components)
+     */
+    debug(...args: Args): string {
+        return this.log('debug', ...args);
+    }
+
+    /**
+     * Log an info level message.
+     * Appropriate for informational messages that may be relevant to consumers of a code
+     * unit.
+     *
+     * Example uses include a router logging when transitions occur or a button logging
+     * clicks.
+     *
+     * @param args Arguments to log (same as console.info)
+     * @return empty string (for use in brackets {} in svelte components)
+     */
+    info(...args: Args): string {
+        return this.log('info', ...args);
+    }
+
+    /**
+     * Log a warn level message.
+     * Appropriate for situations where state has been (or likely will be) corrupted or
+     * invariants have been broken.
+     *
+     * Example uses include a data structure warning when it is used before being fully
+     * initialized.
+     *
+     * @param args Arguments to log (same as console.warn)
+     * @return empty string (for use in brackets {} in svelte components)
+     */
+    warn(...args: Args): string {
+        return this.log('warn', ...args);
+    }
+
+    /**
+     * Log an error message.
+     * Appropriate for thrown errors or situations where the apps breaks or has to
+     * engage in fallback behavior to avoid a more catastrophic failure.
+     *
+     * @param args Arguments to log (same as console.error)
+     * @return empty string (for use in brackets {} in svelte components)
+     */
+    error(...args: Args): string {
+        return this.log('error', ...args);
+    }
+
+    protected abstract log(method: Level, ...args: Args): string;
+}