Add isKey util method

packages/support/src/misc/index.ts

@@ -1,4 +1,5 @@
 export * from './empty';
+export * from './isKey';
 export * from './isPrimitive';
 export * from './isPropertyKey';
 export * from './isset';

packages/support/src/misc/isKey.ts

@@ -0,0 +1,29 @@
+import { isPropertyKey } from "./isPropertyKey";
+
+/**
+ * Determine if given is a valid {@link import('@aedart/contracts/support').Key}
+ * 
+ * @see {isPropertyKey}
+ * 
+ * @param {any} key
+ * 
+ * @returns {boolean}
+ */
+export function isKey(key: any): boolean
+{
+    if (!Array.isArray(key)) {
+        key = [ key ];
+    }
+
+    if (key.length === 0) {
+        return false;
+    }
+
+    for (const entry of key) {
+        if (!isPropertyKey(entry)) {
+            return false;
+        }
+    }
+
+    return true;
+}

tests/browser/packages/support/misc/isKey.test.js

@@ -0,0 +1,43 @@
+import {
+    isKey
+} from '@aedart/support/misc';
+
+describe('@aedart/support/misc', () => {
+    describe('isKey', () => {
+
+        it('can determine if value is a valid key', function () {
+            const valid = [
+                0,
+                1,
+                -1,
+                NaN,
+                'foo',
+                Symbol('my-symbol'),
+                [ 'a', 'b.c' ],
+                [ 'a', 'b.c', 12, Symbol('my-other-symbol') ],
+            ];
+
+            valid.forEach((value, index) => {
+                expect(isKey(value))
+                    .withContext(`Value at index ${index} is not a valid key`)
+                    .toBeTrue();
+            });
+
+            const invalid = [
+                [],
+                () => false,
+                { name: 'John' },
+                true,
+                false,
+                null,
+                undefined
+            ];
+
+            invalid.forEach((value, index) => {
+                expect(isKey(value))
+                    .withContext(`Invalid value at index ${index} SHOULD NOT be a valid key`)
+                    .toBeFalse();
+            });
+        });
+    });
+});