added parent to ObjID

src/types/ObjID.ts

@@ -53,6 +53,30 @@ class ObjID {
 		return new ObjID(this.bucket,parts.join("/"))
 	}
 
+	/**
+	 * Get the parent of the object. If Obj is a file then the containing directory
+	 * if Obj is a directory it returns the parent
+	 * @returns parent ObjID or null if already at root
+	 */
+	public parent(): ObjID | null {
+		if (this.key == "/") {
+			// Already at root. We dont have a parent
+			return null
+		}
+	
+		if (this.isDirectory()) {
+			const parts = this.key.split("/")
+			const parent = new ObjID(this.bucket, parts.slice(0,-2).join("/") + "/")
+			parent.normalize()
+			return parent
+		} else {
+			const parts = this.key.split("/")
+			const parent = new ObjID(this.bucket, parts.slice(0,-1).join("/")  + "/")
+			parent.normalize()
+			return parent
+		}
+	}
+
 	public static fromString(from: string): ObjID{
 		const match = stringRegex.exec(from)