test(function() {

var params = new URLSearchParams('a=b&c=d');

params.delete('a');

assert_equals(params + '', 'c=d');

params = new URLSearchParams('a=a&b=b&a=a&c=c');

params.delete('a');

assert_equals(params + '', 'b=b&c=c');

params = new URLSearchParams('a=a&=&b=b&c=c');

params.delete('');

assert_equals(params + '', 'a=a&b=b&c=c');

params = new URLSearchParams('a=a&null=null&b=b');

params.delete(null);

assert_equals(params + '', 'a=a&b=b');

params = new URLSearchParams('a=a&undefined=undefined&b=b');

params.delete(undefined);

assert_equals(params + '', 'a=a&b=b');

}, 'Delete basics');

test(function() {

var params = new URLSearchParams();

params.append('first', 1);

assert_true(params.has('first'), 'Search params object has name "first"');

assert_equals(params.get('first'), '1', 'Search params object has name "first" with value "1"');

params.delete('first');

assert_false(params.has('first'), 'Search params object has no "first" name');

params.append('first', 1);

params.append('first', 10);

params.delete('first');

assert_false(params.has('first'), 'Search params object has no "first" name');

}, 'Deleting appended multiple');

test(function() {

var url = new URL('http://example.com/?param1&param2');

url.searchParams.delete('param1');

url.searchParams.delete('param2');

assert_equals(url.href, 'http://example.com/', 'url.href does not have ?');

assert_equals(url.search, '', 'url.search does not have ?');

}, 'Deleting all params removes ? from URL');

test(function() {

var url = new URL('http://example.com/?');

url.searchParams.delete('param1');

assert_equals(url.href, 'http://example.com/', 'url.href does not have ?');

assert_equals(url.search, '', 'url.search does not have ?');

}, 'Removing non-existent param removes ? from URL');

test(() => {

const url = new URL('data:space ?test');

assert_true(url.searchParams.has('test'));

url.searchParams.delete('test');

assert_false(url.searchParams.has('test'));

assert_equals(url.search, '');

assert_equals(url.pathname, 'space');

assert_equals(url.href, 'data:space');

}, 'Changing the query of a URL with an opaque path can impact the path');

test(() => {

const url = new URL('data:space ?test#test');

url.searchParams.delete('test');

assert_equals(url.search, '');

assert_equals(url.pathname, 'space ');

assert_equals(url.href, 'data:space #test');

}, 'Changing the query of a URL with an opaque path can impact the path if the URL has no fragment');

test(() => {

const params = new URLSearchParams();

params.append('a', 'b');

params.append('a', 'c');

params.append('a', 'd');

params.delete('a', 'c');

assert_equals(params.toString(), 'a=b&a=d');

}, "Two-argument delete()");

test(() => {

const params = new URLSearchParams();

params.append('a', 'b');

params.append('a', 'c');

params.append('b', 'c');

params.append('b', 'd');

params.delete('b', 'c');

params.delete('a', undefined);

assert_equals(params.toString(), 'b=d');

}, "Two-argument delete() respects undefined as second arg");