From 38fe42fa10d7578ca4315990757937cfcaef9fec Mon Sep 17 00:00:00 2001
From: Wroud <wrouds@gmail.com>
Date: Sun, 26 Apr 2020 20:01:00 +0300
Subject: [PATCH] feat(extensions): implementation

---
 webapp/packages/core/extensions/package.json  |  8 +++++
 .../core/src/extensions/IExtension.ts         | 15 ++++++++++
 .../packages/core/src/extensions/constants.ts | 10 +++++++
 .../core/src/extensions/createExtension.ts    | 30 +++++++++++++++++++
 webapp/packages/core/src/extensions/index.ts  |  2 ++
 5 files changed, 65 insertions(+)
 create mode 100644 webapp/packages/core/extensions/package.json
 create mode 100644 webapp/packages/core/src/extensions/IExtension.ts
 create mode 100644 webapp/packages/core/src/extensions/constants.ts
 create mode 100644 webapp/packages/core/src/extensions/createExtension.ts
 create mode 100644 webapp/packages/core/src/extensions/index.ts

diff --git a/webapp/packages/core/extensions/package.json b/webapp/packages/core/extensions/package.json
new file mode 100644
index 0000000000..3b62caed89
--- /dev/null
+++ b/webapp/packages/core/extensions/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@dbeaver/core/extensions",
+  "private": true,
+  "sideEffects": false,
+  "main": "../dist/extensions",
+  "module": "../dist/extensions",
+  "types": "../dist/types/extensions"
+}
diff --git a/webapp/packages/core/src/extensions/IExtension.ts b/webapp/packages/core/src/extensions/IExtension.ts
new file mode 100644
index 0000000000..b11e5de0e1
--- /dev/null
+++ b/webapp/packages/core/src/extensions/IExtension.ts
@@ -0,0 +1,15 @@
+/*
+ * cloudbeaver - Cloud Database Manager
+ * Copyright (C) 2020 DBeaver Corp and others
+ *
+ * Licensed under the Apache License, Version 2.0.
+ * you may not use this file except in compliance with the License.
+ */
+
+import { EXTENSION_SYMBOL, EXTENSION_TYPE_SYMBOL } from './constants';
+
+
+export interface IExtension<T> {
+  [EXTENSION_SYMBOL]: symbol;
+  [EXTENSION_TYPE_SYMBOL]?: T;
+}
diff --git a/webapp/packages/core/src/extensions/constants.ts b/webapp/packages/core/src/extensions/constants.ts
new file mode 100644
index 0000000000..9e98216e22
--- /dev/null
+++ b/webapp/packages/core/src/extensions/constants.ts
@@ -0,0 +1,10 @@
+/*
+ * cloudbeaver - Cloud Database Manager
+ * Copyright (C) 2020 DBeaver Corp and others
+ *
+ * Licensed under the Apache License, Version 2.0.
+ * you may not use this file except in compliance with the License.
+ */
+
+export const EXTENSION_SYMBOL = Symbol('@extension');
+export const EXTENSION_TYPE_SYMBOL = Symbol('@extension/type');
diff --git a/webapp/packages/core/src/extensions/createExtension.ts b/webapp/packages/core/src/extensions/createExtension.ts
new file mode 100644
index 0000000000..2b3c21ce5c
--- /dev/null
+++ b/webapp/packages/core/src/extensions/createExtension.ts
@@ -0,0 +1,30 @@
+/*
+ * cloudbeaver - Cloud Database Manager
+ * Copyright (C) 2020 DBeaver Corp and others
+ *
+ * Licensed under the Apache License, Version 2.0.
+ * you may not use this file except in compliance with the License.
+ */
+
+import { EXTENSION_SYMBOL } from './constants';
+import { IExtension } from './IExtension';
+
+export function createExtension<T>(
+  extension: object,
+  key: symbol
+): IExtension<T> {
+  return Object.assign(extension, { [EXTENSION_SYMBOL]: key });
+}
+
+export function isExtension<T>(
+  obj: any,
+  key?: symbol,
+): obj is IExtension<T> {
+  if (!(EXTENSION_SYMBOL in obj)) {
+    return false;
+  }
+  if (key && obj[EXTENSION_SYMBOL] !== key) {
+    return false;
+  }
+  return true;
+}
diff --git a/webapp/packages/core/src/extensions/index.ts b/webapp/packages/core/src/extensions/index.ts
new file mode 100644
index 0000000000..4a845dbddb
--- /dev/null
+++ b/webapp/packages/core/src/extensions/index.ts
@@ -0,0 +1,2 @@
+export * from './IExtension';
+export * from './createExtension';