Add .stringifyUrl() method

index.d.ts

@@ -206,3 +206,22 @@ export function stringify(
 Extract a query string from a URL that can be passed into `.parse()`.
 */
 export function extract(url: string): string;
+
+/**
+Stringify an object into a URL with a query string and sorting the keys. The inverse of [`.parseUrl()`](https://github.com/sindresorhus/query-string#parseurlstring-options)
+
+Query items in the `query` property overrides queries in the `url` property.
+
+@example
+```
+queryString.stringifyUrl({url: 'https://foo.bar', query: {foo: 'bar'}});
+//=> 'https://foo.bar?foo=bar'
+
+queryString.stringifyUrl({url: 'https://foo.bar?foo=baz', query: {foo: 'bar'}});
+//=> 'https://foo.bar?foo=bar'
+```
+*/
+export function stringifyUrl(
+	object: ParsedUrl,
+	options?: StringifyOptions
+): string;

index.js

@@ -161,6 +161,16 @@ function removeHash(input) {
 	return input;
 }
 
+function getHash(url) {
+	let hash = '';
+	const hashStart = url.indexOf('#');
+	if (hashStart !== -1) {
+		hash = url.slice(hashStart);
+	}
+
+	return hash;
+}
+
 function extract(input) {
 	input = removeHash(input);
 	const queryStart = input.indexOf('?');
@@ -290,3 +300,17 @@ exports.parseUrl = (input, options) => {
 		query: parse(extract(input), options)
 	};
 };
+
+exports.stringifyUrl = (input, options) => {
+	const url = removeHash(input.url).split('?')[0] || '';
+	const queryFromUrl = this.extract(input.url);
+	const parsedQueryFromUrl = this.parse(queryFromUrl);
+	const hash = getHash(input.url);
+	const query = Object.assign(parsedQueryFromUrl, input.query);
+	let queryString = this.stringify(query, options);
+	if (queryString) {
+		queryString = `?${queryString}`;
+	}
+
+	return `${url}${queryString}${hash}`;
+};

readme.md

@@ -221,6 +221,39 @@ queryString.parseUrl('https://foo.bar?foo=bar');
 //=> {url: 'https://foo.bar', query: {foo: 'bar'}}
 ```
 
+### .stringifyUrl(object, options?)
+
+Stringify an object into a URL with a query string and sorting the keys. The inverse of [`.parseUrl()`](https://github.com/sindresorhus/query-string#parseurlstring-options)
+
+The `options` are the same as for `.stringify()`.
+
+Returns a string with the URL and a query string.
+
+Query items in the `query` property overrides queries in the `url` property.
+
+```js
+queryString.stringifyUrl({url: 'https://foo.bar', query: {foo: 'bar'}});
+//=> 'https://foo.bar?foo=bar'
+
+queryString.stringifyUrl({url: 'https://foo.bar?foo=baz', query: {foo: 'bar'}});
+//=> 'https://foo.bar?foo=bar'
+```
+
+#### object
+
+Type: `object`
+
+##### url
+
+Type: `string`
+
+The URL to stringify.
+
+##### query
+
+Type: `object`
+
+Query items to add to the URL.
 
 ## Nesting
 

test/stringify-url.js

@@ -0,0 +1,38 @@
+import test from 'ava';
+import queryString from '..';
+
+test('stringify URL without a query string', t => {
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar/'}), 'https://foo.bar/');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar/', query: {}}), 'https://foo.bar/');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar/#top', query: {}}), 'https://foo.bar/#top');
+	t.deepEqual(queryString.stringifyUrl({url: '', query: {}}), '');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar?', query: {}}), 'https://foo.bar');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar?foo=bar', query: {}}), 'https://foo.bar?foo=bar');
+});
+
+test('stringify URL with a query string', t => {
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar', query: {foo: 'bar'}}), 'https://foo.bar?foo=bar');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar?', query: {foo: 'bar'}}), 'https://foo.bar?foo=bar');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar/#top', query: {foo: 'bar'}}), 'https://foo.bar/?foo=bar#top');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar', query: {foo: 'bar', a: 'b'}}), 'https://foo.bar?a=b&foo=bar');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar?a=b', query: {foo: ['bar', 'baz']}}), 'https://foo.bar?a=b&foo=bar&foo=baz');
+	t.deepEqual(queryString.stringifyUrl({url: 'https://foo.bar?foo=baz', query: {foo: 'bar'}}), 'https://foo.bar?foo=bar');
+});
+
+test('stringify URL from the result of `parseUrl` without query string', t => {
+	const url = 'https://foo.bar';
+	const parsedUrl = queryString.parseUrl(url);
+	t.deepEqual(queryString.stringifyUrl(parsedUrl), url);
+});
+
+test('stringify URL from the result of `parseUrl` with query string', t => {
+	const url = 'https://foo.bar?foo=bar&foo=baz';
+	const parsedUrl = queryString.parseUrl(url);
+	t.deepEqual(queryString.stringifyUrl(parsedUrl), url);
+});
+
+test('stringify URL from the result of `parseUrl` with query string that contains `=`', t => {
+	const url = 'https://foo.bar?foo=bar=&foo=baz=';
+	const parsedUrl = queryString.parseUrl(url);
+	t.deepEqual(queryString.stringifyUrl(parsedUrl, {encode: false}), url);
+});