add TupleKey method to convert string key back to tuple

src/types/TupleKey.ts

@@ -16,4 +16,9 @@ export class TupleKey<T extends any[]> {
   valueOf(): string {
     return this.strKey;
   }
+
+  static fromExistingStringKey(strKey: string) {
+    const tuple = strKey.split(separator);
+    return new TupleKey(...tuple);
+  }
 }

test/types/TupleKeyTests.test.ts

@@ -28,4 +28,18 @@ describe("TupleKey", () => {
     expect(sampleObject[tupleKey1.toString()]).toEqual("value1");
     expect(sampleObject[(new TupleKey("1", "2")).toString()]).toEqual("value1");
   });
-});
+
+  describe("fromExistingStringKey", () => {
+    it("creates a new TupleKey from an existing string key", () => {
+      const strKey = "hello|there";
+      const tupleKey = TupleKey.fromExistingStringKey(strKey);
+      expect(tupleKey.toString()).toEqual(strKey);
+    });
+
+    it("creates an empty tuple if there is no string", () => {
+      const strKey = "";
+      const tupleKey = TupleKey.fromExistingStringKey(strKey);
+      expect(tupleKey.toString()).toEqual(strKey);
+    })
+  })
+});