refactor: move core-tools to monorepo

packages/core-tools/src/util/guards.ts

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2021 StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+import {JSONSchema7 as JSONSchema} from 'json-schema';
+import {SchemaWithDefinitions} from '../types/schema';
+
+/**
+ * Guard for if a JSON schema is in fact a schema with definitions
+ */
+export function isSchemaWithDefinitions(schema: JSONSchema): schema is SchemaWithDefinitions {
+  return schema.definitions !== undefined;
+}
+
+/**
+ * Guard method for determining if an object (a thing) has a type property with a type of string
+ */
+export function isThingWithType(thing: unknown): thing is {type: string} {
+  return (
+    typeof thing === 'object' &&
+    thing !== null &&
+    'type' in thing &&
+    typeof (thing as {type: unknown}).type === 'string'
+  );
+}