Initial commit

src/util/bitmask.ts

@@ -0,0 +1,54 @@
+/*
+ * 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 { split } from 'lodash'
+
+export const serializedBitmaskRegex = /^(\d*,\d*(,\d*,\d*)*)?$/
+
+export const validateBitmask = (bitmask: string, maxLength: number) => {
+  if (!serializedBitmaskRegex.test(bitmask)) {
+    throw new Error('bitmask does not match regex')
+  }
+
+  if (bitmask === '') {
+    return
+  }
+
+  const splitpoints = split(bitmask, ',').map((item) => parseInt(item, 10))
+
+  if (splitpoints.findIndex((item) => !Number.isSafeInteger(item)) !== -1) {
+    throw new Error('bitmask contains non-safe integers')
+  }
+
+  if (splitpoints.findIndex((item) => item < 0) !== -1) {
+    throw new Error('bitmask contains negative integers')
+  }
+
+  if (splitpoints.findIndex((item) => item > maxLength) !== -1) {
+    throw new Error('bitmask contains integers bigger than maxSize')
+  }
+
+  let previousValue = -1
+
+  splitpoints.forEach((item) => {
+    if (item <= previousValue) {
+      throw new Error('bitmask numbers are not strictly sorted')
+    }
+
+    previousValue = item
+  })
+}