test(validation): add test suite for reference-token validation

Author: char0n

src/test/reference-token.js

@@ -6,6 +6,8 @@ const grammar = new Grammar();
 const parser = new Parser();
 
 const testReferenceToken = (referenceToken) => {
+  if (typeof referenceToken !== 'string') return false;
+
   try {
     return parser.parse(grammar, 'reference-token', referenceToken).success;
   } catch {

test/test/reference-token.js

@@ -0,0 +1,72 @@
+import { assert } from 'chai';
+import { testReferenceToken } from '../../src/index.js';
+
+describe('testReferenceToken', function () {
+  context('valid reference tokens', function () {
+    specify('should return true for valid reference tokens (rfc 6901)', function () {
+      const validTokens = [
+        'foo', // simple name
+        'bar123', // alphanumeric
+        'hello.world', // period is allowed
+        'json_pointer', // underscore allowed
+        '0abcDEF', // mix of cases and digits
+        '~0', // valid escaped '~'
+        '~1', // valid escaped '/'
+        'some~0thing', // mixed escape sequence
+        'some~1thing', // mixed escape sequence
+        'value$', // special character allowed
+        'emoji😀', // unicode allowed
+        'unicodeΩ', // unicode allowed
+        'bar~01', // partial escape followed by invalid char
+        '', // empty
+      ];
+
+      validTokens.forEach((token) => {
+        assert.isTrue(testReferenceToken(token), `failed for token: ${token}`);
+      });
+    });
+  });
+
+  context('invalid reference tokens', function () {
+    specify('should return false for tokens with disallowed characters', function () {
+      const invalidTokens = [
+        'foo/bar', // `/` is not allowed unless escaped
+        'foo~', // `~` must be followed by `0` or `1`
+        'foo~2', // invalid escape sequence
+        'foo~x', // invalid escape sequence
+        '~3', // invalid escape sequence
+        'foo~1bar/', // contains `/`
+        'test~0~', // dangling `~`
+        '/leadingSlash', // must not start with '/'
+        'trailingSlash/', // must not end with '/'
+        'mid~slash/', // misplaced `/`
+      ];
+
+      invalidTokens.forEach((token) => {
+        assert.isFalse(testReferenceToken(token), `failed for token: ${token}`);
+      });
+    });
+  });
+
+  context('edge cases', function () {
+    specify('should return false for non-string inputs', function () {
+      assert.isFalse(testReferenceToken(42));
+      assert.isFalse(testReferenceToken(null));
+      assert.isFalse(testReferenceToken(undefined));
+      assert.isFalse(testReferenceToken({}));
+      assert.isFalse(testReferenceToken([]));
+    });
+
+    specify('should allow a single character if valid', function () {
+      assert.isTrue(testReferenceToken('a'));
+      assert.isTrue(testReferenceToken('1'));
+      assert.isTrue(testReferenceToken('~0'));
+      assert.isTrue(testReferenceToken('~1'));
+    });
+
+    specify('should disallow a single invalid character', function () {
+      assert.isFalse(testReferenceToken('/'));
+      assert.isFalse(testReferenceToken('~'));
+    });
+  });
+});