fix(api): adminDeleteUser handles email usernames

The delete call to StormDB was parsing dots in email addresses as
JSONPath separators and failing to delete the user.

Fixes jagregory#99

integration-tests/aws-sdk/adminDeleteUser.test.ts

@@ -60,6 +60,57 @@ describe(
             .promise()
         ).rejects.toEqual(new UserNotFoundError("User does not exist"));
       });
+
+      it("deletes a user with an email address as a username", async () => {
+        const client = Cognito();
+
+        // create the user
+        const createUserResult = await client
+          .adminCreateUser({
+            UserAttributes: [
+              { Name: "email", Value: "[email protected]" },
+              { Name: "phone_number", Value: "0400000000" },
+            ],
+            Username: "[email protected]",
+            UserPoolId: "test",
+          })
+          .promise();
+
+        // verify they exist
+        const beforeUserResult = await client
+          .adminGetUser({
+            Username: "[email protected]",
+            UserPoolId: "test",
+          })
+          .promise();
+
+        expect(beforeUserResult).toEqual({
+          Enabled: true,
+          UserAttributes: createUserResult.User?.Attributes,
+          UserCreateDate: createUserResult.User?.UserCreateDate,
+          UserLastModifiedDate: createUserResult.User?.UserLastModifiedDate,
+          Username: createUserResult.User?.Username,
+          UserStatus: createUserResult.User?.UserStatus,
+        });
+
+        // delete the user
+        await client
+          .adminDeleteUser({
+            Username: "[email protected]",
+            UserPoolId: "test",
+          })
+          .promise();
+
+        // verify they don't exist anymore
+        await expect(
+          client
+            .adminGetUser({
+              Username: "[email protected]",
+              UserPoolId: "test",
+            })
+            .promise()
+        ).rejects.toEqual(new UserNotFoundError("User does not exist"));
+      });
     },
     {
       clock,

src/services/dataStore/stormDb.ts

@@ -16,7 +16,7 @@ export class StormDBDataStore implements DataStore {
   async delete(ctx: Context, key: string | string[]) {
     ctx.logger.debug({ key }, "DataStore.delete");
     (key instanceof Array ? key : [key])
-      .reduce((acc, k) => acc.get(k), this.db)
+      .reduce((acc, k) => acc.get([k]), this.db)
       .delete(false);
 
     ctx.logger.debug({ store: this.db.value() }, "DataStore.save");