feat(http): serialize search parameters from request options

- Extends URLSearchParams API to include operations for combining
  different URLSearchParams objects:

  These new methods include:
  setAll(otherParams): performs `this.set(key, values[0])` for each
      key/value-list pair in `otherParams`

  appendAll(otherParams): performs `this.append(key, values)` for
      each key/value-list pair in `otherParams`

  replaceAll(otherParams): for each key/value-list pair in
      `otherParams`, replaces current set of values for `key` with
      a copy of the list of values.

- RequestOptions do not merge search params automatically (because
  there are multiple ways to do this). Instead, they replace any
  existing `search` field if `search` is provided. Explicit merging
  is required if merging is desirable.

- Some extra test coverage added.

Closes #2417
Closes #3020

modules/angular2/src/http/base_request_options.ts

@@ -1,8 +1,9 @@
-import {CONST_EXPR, CONST, isPresent} from 'angular2/src/facade/lang';
+import {CONST_EXPR, CONST, isPresent, isString} from 'angular2/src/facade/lang';
 import {Headers} from './headers';
 import {RequestModesOpts, RequestMethods, RequestCacheOpts, RequestCredentialsOpts} from './enums';
 import {IRequestOptions} from './interfaces';
 import {Injectable} from 'angular2/di';
+import {URLSearchParams} from './url_search_params';
 
 /**
  * Creates a request options object similar to the `RequestInit` description
@@ -33,7 +34,9 @@ export class RequestOptions implements IRequestOptions {
   credentials: RequestCredentialsOpts;
   cache: RequestCacheOpts;
   url: string;
-  constructor({method, headers, body, mode, credentials, cache, url}: IRequestOptions = {}) {
+  search: URLSearchParams;
+  constructor({method, headers, body, mode, credentials, cache, url, search}:
+                  IRequestOptions = {}) {
     this.method = isPresent(method) ? method : null;
     this.headers = isPresent(headers) ? headers : null;
     this.body = isPresent(body) ? body : null;
@@ -41,6 +44,9 @@ export class RequestOptions implements IRequestOptions {
     this.credentials = isPresent(credentials) ? credentials : null;
     this.cache = isPresent(cache) ? cache : null;
     this.url = isPresent(url) ? url : null;
+    this.search = isPresent(search) ? (isString(search) ? new URLSearchParams(<string>(search)) :
+                                                          <URLSearchParams>(search)) :
+                                      null;
   }
 
   /**
@@ -56,7 +62,11 @@ export class RequestOptions implements IRequestOptions {
       credentials: isPresent(options) && isPresent(options.credentials) ? options.credentials :
                                                                           this.credentials,
       cache: isPresent(options) && isPresent(options.cache) ? options.cache : this.cache,
-      url: isPresent(options) && isPresent(options.url) ? options.url : this.url
+      url: isPresent(options) && isPresent(options.url) ? options.url : this.url,
+      search: isPresent(options) && isPresent(options.search) ?
+                  (isString(options.search) ? new URLSearchParams(<string>(options.search)) :
+                                              (<URLSearchParams>(options.search)).clone()) :
+                  this.search
     });
   }
 }

modules/angular2/src/http/http.ts

@@ -17,6 +17,7 @@ function mergeOptions(defaultOpts, providedOpts, method, url): RequestOptions {
     newOptions = newOptions.merge(new RequestOptions({
       method: providedOpts.method,
       url: providedOpts.url,
+      search: providedOpts.search,
       headers: providedOpts.headers,
       body: providedOpts.body,
       mode: providedOpts.mode,

modules/angular2/src/http/interfaces.ts

@@ -12,6 +12,10 @@ import {Headers} from './headers';
 import {BaseException} from 'angular2/src/facade/lang';
 import {EventEmitter} from 'angular2/src/facade/async';
 import {Request} from './static_request';
+import {URLSearchParamsUnionFixer, URLSearchParams} from './url_search_params';
+
+// Work around Dartanalyzer problem :(
+const URLSearchParams_UnionFixer = URLSearchParamsUnionFixer;
 
 /**
  * Abstract class from which real backends are derived.
@@ -41,6 +45,7 @@ export class Connection {
 export interface IRequestOptions {
   url?: string;
   method?: RequestMethods;
+  search?: string | URLSearchParams;
   headers?: Headers;
   // TODO: Support Blob, ArrayBuffer, JSON, URLSearchParams, FormData
   body?: string;

modules/angular2/src/http/static_request.ts

@@ -6,7 +6,8 @@ import {
   RegExpWrapper,
   CONST_EXPR,
   isPresent,
-  isJsObject
+  isJsObject,
+  StringWrapper
 } from 'angular2/src/facade/lang';
 
 // TODO(jeffbcross): properly implement body accessors
@@ -39,7 +40,19 @@ export class Request {
   cache: RequestCacheOpts;
   constructor(requestOptions: RequestOptions) {
     // TODO: assert that url is present
+    let url = requestOptions.url;
     this.url = requestOptions.url;
+    if (isPresent(requestOptions.search)) {
+      let search = requestOptions.search.toString();
+      if (search.length > 0) {
+        let prefix = '?';
+        if (StringWrapper.contains(this.url, '?')) {
+          prefix = (this.url[this.url.length - 1] == '&') ? '' : '&';
+        }
+        // TODO: just delete search-query-looking string in url?
+        this.url = url + prefix + search;
+      }
+    }
     this._body = requestOptions.body;
     this.method = requestOptions.method;
     // TODO(jeffbcross): implement behavior

modules/angular2/src/http/url_search_params.ts

@@ -1,4 +1,4 @@
-import {isPresent, isBlank, StringWrapper} from 'angular2/src/facade/lang';
+import {CONST_EXPR, isPresent, isBlank, StringWrapper} from 'angular2/src/facade/lang';
 import {
   Map,
   MapWrapper,
@@ -7,8 +7,9 @@ import {
   isListLikeIterable
 } from 'angular2/src/facade/collection';
 
-function paramParser(rawParams: string): Map<string, List<string>> {
+function paramParser(rawParams: string = ''): Map<string, List<string>> {
   var map: Map<string, List<string>> = new Map();
+  if (rawParams.length > 0) {
     var params: List<string> = StringWrapper.split(rawParams, new RegExp('&'));
     ListWrapper.forEach(params, (param: string) => {
       var split: List<string> = StringWrapper.split(param, new RegExp('='));
@@ -18,17 +19,30 @@ function paramParser(rawParams: string): Map<string, List<string>> {
       list.push(val);
       map.set(key, list);
     });
+  }
   return map;
 }
 
+// TODO(caitp): This really should not be needed. Issue with ts2dart.
+export const URLSearchParamsUnionFixer: string = CONST_EXPR("UnionFixer");
+
 /**
  * Map-like representation of url search parameters, based on
- * [URLSearchParams](https://url.spec.whatwg.org/#urlsearchparams) in the url living standard.
+ * [URLSearchParams](https://url.spec.whatwg.org/#urlsearchparams) in the url living standard,
- *
+ * with several extensions for merging URLSearchParams objects:
+ *   - setAll()
+ *   - appendAll()
+ *   - replaceAll()
  */
 export class URLSearchParams {
   paramsMap: Map<string, List<string>>;
-  constructor(public rawParams: string) { this.paramsMap = paramParser(rawParams); }
+  constructor(public rawParams: string = '') { this.paramsMap = paramParser(rawParams); }
+
+  clone(): URLSearchParams {
+    var clone = new URLSearchParams();
+    clone.appendAll(this);
+    return clone;
+  }
 
   has(param: string): boolean { return this.paramsMap.has(param); }
 
@@ -46,6 +60,30 @@ export class URLSearchParams {
     return isPresent(mapParam) ? mapParam : [];
   }
 
+  set(param: string, val: string) {
+    var mapParam = this.paramsMap.get(param);
+    var list = isPresent(mapParam) ? mapParam : [];
+    ListWrapper.clear(list);
+    list.push(val);
+    this.paramsMap.set(param, list);
+  }
+
+  // A merge operation
+  // For each name-values pair in `searchParams`, perform `set(name, values[0])`
+  //
+  // E.g: "a=[1,2,3], c=[8]" + "a=[4,5,6], b=[7]" = "a=[4], c=[8], b=[7]"
+  //
+  // TODO(@caitp): document this better
+  setAll(searchParams: URLSearchParams) {
+    MapWrapper.forEach(searchParams.paramsMap, (value, param) => {
+      var mapParam = this.paramsMap.get(param);
+      var list = isPresent(mapParam) ? mapParam : [];
+      ListWrapper.clear(list);
+      list.push(value[0]);
+      this.paramsMap.set(param, list);
+    });
+  }
+
   append(param: string, val: string): void {
     var mapParam = this.paramsMap.get(param);
     var list = isPresent(mapParam) ? mapParam : [];
@@ -53,6 +91,44 @@ export class URLSearchParams {
     this.paramsMap.set(param, list);
   }
 
+  // A merge operation
+  // For each name-values pair in `searchParams`, perform `append(name, value)`
+  // for each value in `values`.
+  //
+  // E.g: "a=[1,2], c=[8]" + "a=[3,4], b=[7]" = "a=[1,2,3,4], c=[8], b=[7]"
+  //
+  // TODO(@caitp): document this better
+  appendAll(searchParams: URLSearchParams) {
+    MapWrapper.forEach(searchParams.paramsMap, (value, param) => {
+      var mapParam = this.paramsMap.get(param);
+      var list = isPresent(mapParam) ? mapParam : [];
+      for (var i = 0; i < value.length; ++i) {
+        list.push(value[i]);
+      }
+      this.paramsMap.set(param, list);
+    });
+  }
+
+
+  // A merge operation
+  // For each name-values pair in `searchParams`, perform `delete(name)`,
+  // followed by `set(name, values)`
+  //
+  // E.g: "a=[1,2,3], c=[8]" + "a=[4,5,6], b=[7]" = "a=[4,5,6], c=[8], b=[7]"
+  //
+  // TODO(@caitp): document this better
+  replaceAll(searchParams: URLSearchParams) {
+    MapWrapper.forEach(searchParams.paramsMap, (value, param) => {
+      var mapParam = this.paramsMap.get(param);
+      var list = isPresent(mapParam) ? mapParam : [];
+      ListWrapper.clear(list);
+      for (var i = 0; i < value.length; ++i) {
+        list.push(value[i]);
+      }
+      this.paramsMap.set(param, list);
+    });
+  }
+
   toString(): string {
     var paramsList = [];
     MapWrapper.forEach(this.paramsMap, (values, k) => {

modules/angular2/test/http/http_spec.ts

@@ -21,6 +21,7 @@ import {ResponseOptions} from 'angular2/src/http/base_response_options';
 import {Request} from 'angular2/src/http/static_request';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/facade/async';
 import {ConnectionBackend} from 'angular2/src/http/interfaces';
+import {URLSearchParams} from 'angular2/src/http/url_search_params';
 
 class SpyObserver extends SpyObject {
   onNext: Function;
@@ -202,6 +203,47 @@ export function main() {
              ObservableWrapper.subscribe(http.head(url), res => {});
            }));
       });
+
+
+      describe('searchParams', () => {
+        it('should append search params to url', inject([AsyncTestCompleter], async => {
+             var params = new URLSearchParams();
+             params.append('q', 'puppies');
+             ObservableWrapper.subscribe<MockConnection>(backend.connections, c => {
+               expect(c.request.url).toEqual('https://www.google.com?q=puppies');
+               backend.resolveAllConnections();
+               async.done();
+             });
+             ObservableWrapper.subscribe(
+                 http.get('https://www.google.com', new RequestOptions({search: params})),
+                 res => {});
+           }));
+
+
+        it('should append string search params to url', inject([AsyncTestCompleter], async => {
+             ObservableWrapper.subscribe<MockConnection>(backend.connections, c => {
+               expect(c.request.url).toEqual('https://www.google.com?q=piggies');
+               backend.resolveAllConnections();
+               async.done();
+             });
+             ObservableWrapper.subscribe(
+                 http.get('https://www.google.com', new RequestOptions({search: 'q=piggies'})),
+                 res => {});
+           }));
+
+
+        it('should produce valid url when url already contains a query',
+           inject([AsyncTestCompleter], async => {
+             ObservableWrapper.subscribe<MockConnection>(backend.connections, c => {
+               expect(c.request.url).toEqual('https://www.google.com?q=angular&as_eq=1.x');
+               backend.resolveAllConnections();
+               async.done();
+             });
+             ObservableWrapper.subscribe(http.get('https://www.google.com?q=angular',
+                                                  new RequestOptions({search: 'as_eq=1.x'})),
+                                         res => {});
+           }));
+      });
     });
   });
 }

modules/angular2/test/http/url_search_params_spec.ts

@@ -30,6 +30,51 @@ export function main() {
       expect(searchParams.toString()).toEqual("q=URLUtils.searchParams&topic=api&topic=webdev");
       searchParams.delete("topic");
       expect(searchParams.toString()).toEqual("q=URLUtils.searchParams");
+
+      // Test default constructor
+      expect(new URLSearchParams().toString()).toBe("");
+    });
+
+
+    it('should support map-like merging operation via setAll()', () => {
+      var mapA = new URLSearchParams('a=1&a=2&a=3&c=8');
+      var mapB = new URLSearchParams('a=4&a=5&a=6&b=7');
+      mapA.setAll(mapB);
+      expect(mapA.has('a')).toBe(true);
+      expect(mapA.has('b')).toBe(true);
+      expect(mapA.has('c')).toBe(true);
+      expect(mapA.getAll('a')).toEqual(['4']);
+      expect(mapA.getAll('b')).toEqual(['7']);
+      expect(mapA.getAll('c')).toEqual(['8']);
+      expect(mapA.toString()).toEqual('a=4&c=8&b=7');
+    });
+
+
+    it('should support multimap-like merging operation via appendAll()', () => {
+      var mapA = new URLSearchParams('a=1&a=2&a=3&c=8');
+      var mapB = new URLSearchParams('a=4&a=5&a=6&b=7');
+      mapA.appendAll(mapB);
+      expect(mapA.has('a')).toBe(true);
+      expect(mapA.has('b')).toBe(true);
+      expect(mapA.has('c')).toBe(true);
+      expect(mapA.getAll('a')).toEqual(['1', '2', '3', '4', '5', '6']);
+      expect(mapA.getAll('b')).toEqual(['7']);
+      expect(mapA.getAll('c')).toEqual(['8']);
+      expect(mapA.toString()).toEqual('a=1&a=2&a=3&a=4&a=5&a=6&c=8&b=7');
+    });
+
+
+    it('should support multimap-like merging operation via replaceAll()', () => {
+      var mapA = new URLSearchParams('a=1&a=2&a=3&c=8');
+      var mapB = new URLSearchParams('a=4&a=5&a=6&b=7');
+      mapA.replaceAll(mapB);
+      expect(mapA.has('a')).toBe(true);
+      expect(mapA.has('b')).toBe(true);
+      expect(mapA.has('c')).toBe(true);
+      expect(mapA.getAll('a')).toEqual(['4', '5', '6']);
+      expect(mapA.getAll('b')).toEqual(['7']);
+      expect(mapA.getAll('c')).toEqual(['8']);
+      expect(mapA.toString()).toEqual('a=4&a=5&a=6&c=8&b=7');
     });
   });
 }