From 00febde261e1b8dd121d49bbb54554355344dae0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Gorej?= <vladimir.gorej@smartbear.com>
Date: Tue, 31 Oct 2023 14:13:11 +0100
Subject: [PATCH] feat(logging): add Placeholder implementation (#3345)

Refs #3197
---
 packages/apidom-logging/src/Logger.ts      |  1 +
 packages/apidom-logging/src/Placeholder.ts | 23 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 packages/apidom-logging/src/Logger.ts
 create mode 100644 packages/apidom-logging/src/Placeholder.ts

diff --git a/packages/apidom-logging/src/Logger.ts b/packages/apidom-logging/src/Logger.ts
new file mode 100644
index 0000000000..e82a4aa0eb
--- /dev/null
+++ b/packages/apidom-logging/src/Logger.ts
@@ -0,0 +1 @@
+export interface LoggerInstance {}
diff --git a/packages/apidom-logging/src/Placeholder.ts b/packages/apidom-logging/src/Placeholder.ts
new file mode 100644
index 0000000000..1714a55b97
--- /dev/null
+++ b/packages/apidom-logging/src/Placeholder.ts
@@ -0,0 +1,23 @@
+import type { LoggerInstance } from './Logger';
+
+type LoggerHierarchyInstance = LoggerInstance | PlaceholderInstance;
+
+export interface PlaceholderInstance {
+  readonly loggerMap: Map<LoggerHierarchyInstance, LoggerHierarchyInstance | null>;
+  append(logger: LoggerHierarchyInstance): void;
+}
+class Placeholder implements PlaceholderInstance {
+  public readonly loggerMap: Map<LoggerHierarchyInstance, LoggerHierarchyInstance | null>;
+
+  constructor(logger: LoggerHierarchyInstance) {
+    this.loggerMap = new Map([[logger, null]]);
+  }
+
+  public append(logger: LoggerHierarchyInstance): void {
+    if (!this.loggerMap.has(logger)) {
+      this.loggerMap.set(logger, null);
+    }
+  }
+}
+
+export default Placeholder;