Add comprehensive test coverage for queryString.exclude()

Fixes #402

Author: sindresorhus

test/exclude.js

@@ -19,3 +19,68 @@ test('excludes elements in a URL with a filter predicate', t => {
 test('excludes elements in a URL without encoding fragment identifiers', t => {
 	t.is(queryString.exclude('https://example.com?a=b#/home', ['a']), 'https://example.com#/home');
 });
+
+test('handles empty filter array', t => {
+	t.is(queryString.exclude('http://example.com/?a=1&b=2&c=3', []), 'http://example.com/?a=1&b=2&c=3');
+});
+
+test('handles excluding non-existent parameters', t => {
+	t.is(queryString.exclude('http://example.com/?a=1&b=2', ['c', 'd']), 'http://example.com/?a=1&b=2');
+});
+
+test('handles multiple values for same parameter', t => {
+	t.is(queryString.exclude('http://example.com/?a=1&a=2&b=3', ['b']), 'http://example.com/?a=1&a=2');
+});
+
+test('handles special characters in parameter names', t => {
+	t.is(queryString.exclude('http://example.com/?foo%5Bbar%5D=1&normal=2', ['foo[bar]']), 'http://example.com/?normal=2');
+});
+
+test('handles URL without query parameters', t => {
+	t.is(queryString.exclude('http://example.com/', ['a']), 'http://example.com/');
+	t.is(queryString.exclude('http://example.com/#hash', ['a']), 'http://example.com/#hash');
+});
+
+test('excludes all parameters when filter matches everything', t => {
+	t.is(queryString.exclude('http://example.com/?a=1&b=2&c=3', ['a', 'b', 'c']), 'http://example.com/');
+});
+
+test('preserves URL path when excluding parameters', t => {
+	t.is(queryString.exclude('http://example.com/path/to/page?a=1&b=2', ['a']), 'http://example.com/path/to/page?b=2');
+});
+
+test('handles empty string values', t => {
+	t.is(queryString.exclude('http://example.com/?a=&b=2&c=', ['b']), 'http://example.com/?a=&c=');
+});
+
+test('handles parameters without values', t => {
+	t.is(queryString.exclude('http://example.com/?a&b=2&c', ['b']), 'http://example.com/?a&c');
+});
+
+test('filter predicate receives correct arguments for array values', t => {
+	const url = 'http://example.com/?a=1&a=2&b=3';
+	const result = queryString.exclude(url, (name, value) => {
+		if (name === 'a') {
+			t.true(Array.isArray(value));
+			t.deepEqual(value, ['1', '2']);
+			return true;
+		}
+
+		return false;
+	});
+	t.is(result, 'http://example.com/?b=3');
+});
+
+test('handles relative URLs', t => {
+	t.is(queryString.exclude('/path?a=1&b=2', ['a']), '/path?b=2');
+	t.is(queryString.exclude('?a=1&b=2', ['b']), '?a=1');
+});
+
+test('handles fragments with special characters', t => {
+	t.is(queryString.exclude('http://example.com/?a=1#section/subsection', ['a']), 'http://example.com/#section/subsection');
+});
+
+test('handles complex nested parameter names', t => {
+	const result = queryString.exclude('http://example.com/?user[name]=John&user[age]=30&id=1', ['user[name]']);
+	t.true(result === 'http://example.com/?user%5Bage%5D=30&id=1' || result === 'http://example.com/?id=1&user%5Bage%5D=30');
+});