feat: add isIndexed (#1337)

Closes #1236

src/index.js

@@ -81,6 +81,7 @@ export { default as isSet } from './isSet';
 export { default as isSparseArray } from './isSparseArray';
 export { default as isSymbol } from './isSymbol';
 export { default as isSafeInteger } from './isSafeInteger';
+export { default as isIndexed } from './isIndexed';
 // Function
 export { default as stubUndefined } from './stubUndefined';
 export { default as stubNull } from './stubNull';

src/isIndexed.js

@@ -0,0 +1,25 @@
+import { either } from 'ramda';
+import curry1 from 'ramda/src/internal/_curry1';
+
+import isArray from './isArray';
+import isString from './isString';
+
+/**
+ * Determine if input value is an indexed data type.
+ *
+ * @func isIndexed
+ * @memberOf RA
+ * @since {@link https://char0n.github.io/ramda-adjunct/2.26.0|v2.26.0}
+ * @category Type
+ * @sig * -> Boolean
+ * @param {*} val The value to test
+ * @return {boolean}
+ * @example
+ *
+ * RA.isIndexed([1]) //=> true
+ * RA.isIndexed('test') //=> true
+ */
+
+const isIndexed = curry1(either(isString, isArray));
+
+export default isIndexed;

test/isIndexed.js

@@ -0,0 +1,37 @@
+import { assert } from 'chai';
+import * as R from 'ramda';
+
+import * as RA from '../src';
+
+describe('isIndexed', function() {
+  context('given a `String` value', function() {
+    specify('should return true', function() {
+      assert.isTrue(RA.isIndexed('test'));
+      assert.isTrue(RA.isIndexed(Object('test')));
+      assert.isTrue(RA.isIndexed(''));
+    });
+  });
+
+  context('given array value', function() {
+    specify('should return true', function() {
+      assert.isTrue(RA.isIndexed([]));
+      assert.isTrue(RA.isIndexed([1, 2]));
+    });
+  });
+
+  context('given a non `String` or `Array` value', function() {
+    specify('should return false', function() {
+      assert.isFalse(RA.isIndexed(true));
+      assert.isFalse(RA.isIndexed(new Date()));
+      assert.isFalse(RA.isIndexed(new Error()));
+      assert.isFalse(RA.isIndexed({ 0: 1, length: 1 }));
+      assert.isFalse(RA.isIndexed(1));
+    });
+  });
+
+  it('should support placeholder to specify "gaps"', function() {
+    const isIndexed = RA.isIndexed(R.__);
+
+    assert.isTrue(isIndexed([]));
+  });
+});

types/index.d.ts

@@ -1350,6 +1350,11 @@ declare namespace RamdaAdjunct {
          */
         sortByProps(props: string[], list: object[]): object[];
         sortByProps(props: string[]): (list: object[]) => object[];
+
+        /**
+         * Determine if input value is an indexed data type.
+         */
+        isIndexed(val: any): val is string | any[];
     }
 }
 

types/test/isIndexed.ts

@@ -0,0 +1,18 @@
+import * as RA from 'ramda-adjunct';
+
+RA.isIndexed(-0); // $ExpectType boolean
+RA.isIndexed(+0); // $ExpectType boolean
+RA.isIndexed(null); // $ExpectType boolean
+RA.isIndexed(true); // $ExpectType boolean
+RA.isIndexed(NaN); // $ExpectType boolean
+RA.isIndexed({}); // $ExpectType boolean
+RA.isIndexed([]); // $ExpectType boolean
+RA.isIndexed(() => {}); // $ExpectType boolean
+RA.isIndexed('string'); // $ExpectType boolean
+RA.isIndexed(1); // $ExpectType boolean
+RA.isIndexed(0.1); // $ExpectType boolean
+RA.isIndexed(Object(0.1)); // $ExpectType boolean
+RA.isIndexed(NaN); // $ExpectType boolean
+RA.isIndexed(Infinity); // $ExpectType boolean
+RA.isIndexed(Number.MAX_VALUE); // $ExpectType boolean
+RA.isIndexed(Number.MIN_VALUE); // $ExpectType boolean