(init): Add initial logger files.

src/Logger.ts

@@ -0,0 +1,44 @@
+import LogLevel from './typings/LogLevel';
+import Transport from './typings/Transport';
+
+export class Logger {
+  private transports: Transport[];
+
+  constructor(transports: Transport[] = []) {
+    this.transports = transports;
+  }
+
+  async log(level: LogLevel, module: string, content: string): Promise<void> {
+    const tasks: Promise<void>[] = [];
+
+    for (const transport of this.transports) {
+      if (level >= transport.minLevel) {
+        tasks.push(transport.log(level, module, content));
+      }
+    }
+
+    await Promise.all(tasks);
+  }
+
+  debug(module: string, content: string) {
+    return this.log(LogLevel.Debug, module, content);
+  }
+
+  info(module: string, content: string) {
+    return this.log(LogLevel.Information, module, content);
+  }
+
+  warn(module: string, content: string) {
+    return this.log(LogLevel.Warning, module, content);
+  }
+
+  error(module: string, content: string) {
+    return this.log(LogLevel.Error, module, content);
+  }
+
+  fatal(module: string, content: string) {
+    return this.log(LogLevel.Fatal, module, content);
+  }
+}
+
+export default Logger;