Fix(isLength): Correctly handle Unicode variation selectors

Author: koral--

src/lib/isLength.js

@@ -14,7 +14,7 @@ export default function isLength(str, options) {
     max = arguments[2];
   }
 
-  const presentationSequences = str.match(/(\uFE0F|\uFE0E)/g) || [];
+  const presentationSequences = str.match(/[^\uFE0F\uFE0E][\uFE0F\uFE0E]/g) || [];
   const surrogatePairs = str.match(/[\uD800-\uDBFF][\uDC00-\uDFFF]/g) || [];
   const len = str.length - presentationSequences.length - surrogatePairs.length;
   const isInsideRange = len >= min && (typeof max === 'undefined' || len <= max);

test/validators/isLength.test.js

@@ -0,0 +1,45 @@
+import test from '../testFunctions';
+
+describe('isLength', () => {
+  it('should return false for a string with length greater than the max', () => {
+    test({
+      validator: 'isLength',
+      args: [{ max: 3 }],
+      invalid: ['test'],
+    });
+  });
+
+  it('should return true for a string with length equal to the max', () => {
+    test({
+      validator: 'isLength',
+      args: [{ max: 4 }],
+      valid: ['test'],
+    });
+  });
+
+  it('should correctly calculate the length of a string with presentation sequences', () => {
+    test({
+      validator: 'isLength',
+      args: [{ max: 4 }],
+      valid: ['test\uFE0F'],
+    });
+
+    test({
+      validator: 'isLength',
+      args: [{ min: 5, max: 5 }],
+      valid: ['test\uFE0F\uFE0F'],
+    });
+
+    test({
+      validator: 'isLength',
+      args: [{ min: 5, max: 5 }],
+      valid: ['\uFE0Ftest'],
+    });
+
+    test({
+      validator: 'isLength',
+      args: [{ min: 9, max: 9 }],
+      valid: ['test\uFE0F\uFE0F\uFE0F\uFE0F\uFE0F\uFE0F'],
+    });
+  });
+});