Initial commit

src/util/list.ts

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+/*
+ * server component for the TimeLimit App
+ * Copyright (C) 2019 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import { uniq } from 'lodash'
+
+export function assertNonEmptyListWithoutDuplicates (list: Array<string>) {
+  if (list.length === 0) {
+    throw new Error('expected not empty list')
+  }
+
+  if (uniq(list).length !== list.length) {
+    throw new Error('expected list without duplicates')
+  }
+}