[ui/url] add modifyUrl() helper

src/ui/public/url/__tests__/modify_url.js

@@ -0,0 +1,44 @@
+import { parse as parseUrl } from 'url';
+
+import expect from 'expect.js';
+
+import { modifyUrl } from '../modify_url';
+
+describe('modifyUrl()', () => {
+  it('throws an error with invalid input', () => {
+    expect(() => modifyUrl(1, () => {})).to.throwError();
+    expect(() => modifyUrl(undefined, () => {})).to.throwError();
+    expect(() => modifyUrl('http://localhost')).to.throwError(); // no block
+  });
+
+  it('supports returning a new url spec', () => {
+    expect(modifyUrl('http://localhost', () => ({}))).to.eql('');
+  });
+
+  it('supports modifying the passed object', () => {
+    expect(modifyUrl('http://localhost', parsed => {
+      parsed.port = 9999;
+      parsed.auth = 'foo:bar';
+    })).to.eql('http://foo:bar@localhost:9999/');
+  });
+
+  it('supports changing pathname', () => {
+    expect(modifyUrl('http://localhost/some/path', parsed => {
+      parsed.pathname += '/subpath';
+    })).to.eql('http://localhost/some/path/subpath');
+  });
+
+  it('supports changing port', () => {
+    expect(modifyUrl('http://localhost:5601', parsed => {
+      parsed.port = (parsed.port * 1) + 1;
+    })).to.eql('http://localhost:5602/');
+  });
+
+  it('supports changing protocol', () => {
+    expect(modifyUrl('http://localhost', parsed => {
+      parsed.protocol = 'mail';
+      parsed.slashes = false;
+      parsed.pathname = null;
+    })).to.eql('mail:localhost');
+  });
+});

src/ui/public/url/index.js

@@ -0,0 +1,2 @@
+export { KbnUrlProvider as default } from './url';
+export { modifyUrl } from './modify_url';

src/ui/public/url/modify_url.js

@@ -0,0 +1,61 @@
+import { parse as parseUrl, format as formatUrl } from 'url';
+
+/**
+ *  Takes a URL and a function that takes the meaningful parts
+ *  of the URL as a key-value object, modifies some or all of
+ *  the parts, and returns the modified parts formatted again
+ *  as a url.
+ *
+ *  Url Parts sent:
+ *    - protocol
+ *    - slashes (does the url have the //)
+ *    - auth
+ *    - hostname (just the name of the host, no port or auth information)
+ *    - port
+ *    - pathmame (the path after the hostname, no query or hash, starts
+ *        with a slash if there was a path)
+ *    - query (always an object, even when no query on original url)
+ *    - hash
+ *
+ *  Why?
+ *    - The default url library in node produces several conflicting
+ *      properties on the "parsed" output. Modifying any of these might
+ *      lead to the modifications being ignored (depending on which
+ *      property was modified)
+ *    - It's not always clear wither to use path/pathname, host/hostname,
+ *      so this trys to add helpful constraints
+ *
+ *  @param  {String} url - the url to parse
+ *  @param  {Function<Object|undefined>} block - a function that will modify the parsed url, or return a new one
+ *  @return {String} the modified and reformatted url
+ */
+export function modifyUrl(url, block) {
+  if (typeof block !== 'function') {
+    throw new TypeError('You must pass a block to define the modifications desired');
+  }
+
+  const parsed = parseUrl(url, true);
+
+  // copy over the most specific version of each
+  // property. By default, the parsed url includes
+  // several conflicting properties (like path and
+  // pathname + search, or search and query) and keeping
+  // track of which property is actually used when they
+  // are formatted is harder than necessary
+  const meaningfulParts = {
+    protocol: parsed.protocol,
+    slashes: parsed.slashes,
+    auth: parsed.auth,
+    hostname: parsed.hostname,
+    port: parsed.port,
+    pathname: parsed.pathname,
+    query: parsed.query || {},
+    hash: parsed.hash,
+  };
+
+  // the block modifies the meaningfulParts object, or returns a new one
+  const modifications = block(meaningfulParts) || meaningfulParts;
+
+  // format the modified/replaced meaningfulParts back into a url
+  return formatUrl(modifications);
+}

src/ui/public/url/url.js

@@ -8,7 +8,7 @@ import AppStateProvider from 'ui/state_management/app_state';
 uiModules.get('kibana/url')
 .service('kbnUrl', function (Private) { return Private(KbnUrlProvider); });
 
-function KbnUrlProvider($injector, $location, $rootScope, $parse, Private) {
+export function KbnUrlProvider($injector, $location, $rootScope, $parse, Private) {
   const self = this;
 
   /**
@@ -207,5 +207,3 @@ function KbnUrlProvider($injector, $location, $rootScope, $parse, Private) {
     return (reloadOnSearch && searchSame) || !reloadOnSearch;
   };
 }
-
-export default KbnUrlProvider;