docs: minor fixes (anchor tags, redundant whitespace, consistent code-snippets lang) (#21589)

PR Close #21589

aio/content/guide/aot-compiler.md

@@ -353,7 +353,7 @@ and [arrow functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Re
 
 Consider the following component decorator:
 
-```ts
+```typescript
 @Component({
   ...
   providers: [{provide: server, useFactory: () => new Server()}]
@@ -367,7 +367,7 @@ When the compiler later interprets this node, it reports an error that invites y
 
 You can fix the error by converting to this:
 
-```ts
+```typescript
 export function serverFactory() {
   return new Server();
 }
@@ -406,7 +406,7 @@ module-local `const` declarations and initialized `var` and `let` declarations,
 
 Consider the following component definition:
 
-```ts
+```typescript
 const template = '<div>{{hero.name}}</div>';
 
 @Component({
@@ -423,7 +423,7 @@ The compiler could not refer to the `template` constant because it isn't exporte
 But the _collector_ can _fold_ the `template` constant into the metadata definition by inlining its contents.
 The effect is the same as if you had written:
 
-```TypeScript
+```typescript
 @Component({
   selector: 'app-hero',
   template: '<div>{{hero.name}}</div>'
@@ -437,7 +437,7 @@ There is no longer a reference to `template` and, therefore, nothing to trouble
 
 You can take this example a step further by including the `template` constant in another expression:
 
-```TypeScript
+```typescript
 const template = '<div>{{hero.name}}</div>';
 
 @Component({
@@ -495,7 +495,7 @@ Decorated component class members must be public. You cannot make an `@Input()`
 
 Data bound properties must also be public.
 
-```TypeScript
+```typescript
 // BAD CODE - title is private
 @Component({
   selector: 'app-root',
@@ -547,7 +547,7 @@ methods that return an expression.
 
 For example, consider the following function:
 
-```TypeScript
+```typescript
 export function wrapInArray<T>(value: T): T[] {
   return [value];
 }
@@ -557,7 +557,7 @@ You can call the `wrapInArray` in a metadata definition because it returns the v
 
 You might use  `wrapInArray()` like this:
 
-```TypeScript
+```typescript
 @NgModule({
   declarations: wrapInArray(TypicalComponent)
 })
@@ -566,7 +566,7 @@ export class TypicalModule {}
 
 The compiler treats this usage as if you had written:
 
-```TypeScript
+```typescript
 @NgModule({
   declarations: [TypicalComponent]
 })
@@ -580,7 +580,8 @@ The Angular [`RouterModule`](api/router/RouterModule) exports two macro static m
 Review the [source code](https://github.com/angular/angular/blob/master/packages/router/src/router_module.ts#L139 "RouterModule.forRoot source code")
 for these methods to see how macros can simplify configuration of complex [NgModules](guide/ngmodules).
 
-{@ metadata-rewriting}
+{@a metadata-rewriting}
+
 ### Metadata rewriting
 
 The compiler treats object literals containing the fields `useClass`, `useValue`, `useFactory`, and `data` specially. The compiler converts the expression initializing one of these fields into an exported variable, which replaces the expression. This process of rewriting these expressions removes all the restrictions on what can be in them because
@@ -590,7 +591,7 @@ the compiler doesn't need to know the expression's value&mdash;it just needs to
 
 You might write something like:
 
-```ts
+```typescript
 class TypicalServer {
 
 }
@@ -605,7 +606,7 @@ Without rewriting, this would be invalid because lambdas are not supported and `
 
 To allow this, the compiler automatically rewrites this to something like:
 
-```ts
+```typescript
 class TypicalServer {
 
 }
@@ -1146,7 +1147,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
 
   For example, consider the following component:
 
-  ```ts
+  ```typescript
   @Component({
     selector: 'my-component',
     template: '{{person.addresss.street}}'
@@ -1183,7 +1184,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
   `Object is possibly 'undefined'` error in the template above, modify it to only emit the
   interpolation if the value of `person` is initialized as shown below:
 
-  ```ts
+  ```typescript
   @Component({
     selector: 'my-component',
     template: '<span *ngIf="person"> {{person.addresss.street}} </span>'
@@ -1202,7 +1203,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
   a static member marker that is a signal to the template compiler to treat them
   like `*ngIf`. This static member for `*ngIf` is:
 
-  ```ts
+  ```typescript
     public static ngIfUseIfTypeGuard: void;
   ```
 
@@ -1223,7 +1224,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
   way to describe this constraint to TypeScript and the template compiler, but the error
   is suppressed in the example by using `address!.street`.
 
-  ```ts
+  ```typescript
   @Component({
     selector: 'my-component',
     template: '<span *ngIf="person"> {{person.name}} lives on {{address!.street}} </span>'
@@ -1245,7 +1246,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
   In this example it is recommended to include the checking of `address`
   in the `*ngIf`as shown below:
 
-  ```ts
+  ```typescript
   @Component({
     selector: 'my-component',
     template: '<span *ngIf="person && address"> {{person.name}} lives on {{address.street}} </span>'
@@ -1271,7 +1272,7 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
   In the following example, the error `Property addresss does not exist` is suppressed
   by casting `person` to the `any` type.
 
-  ```ts
+  ```typescript
   @Component({
     selector: 'my-component',
     template: '{{$any(person).addresss.street}}'
@@ -1289,4 +1290,3 @@ Chuck: After reviewing your PR comment I'm still at a loss. See [comment there](
 * Macro-functions and macro-static methods.
 * Compiler errors related to metadata.
 * Validation of binding expressions
-

aio/content/guide/bootstrapping.md

@@ -14,7 +14,7 @@ By convention, it is usually called `AppModule`.
 
 If you use the CLI to generate an app, the default `AppModule` is as follows:
 
-```javascript
+```typescript
 /* JavaScript imports */
 import { BrowserModule } from '@angular/platform-browser';
 import { NgModule } from '@angular/core';
@@ -78,7 +78,7 @@ this module and the other module imports this one.
 
 An example of what goes into a declarations array follows:
 
-```javascript
+```typescript
   declarations: [
     YourComponent,
     YourPipe,
@@ -178,4 +178,3 @@ root module's `bootstrap` array.
 
 For more on NgModules you're likely to see frequently in apps,
 see [Frequently Used Modules](#).
-

aio/content/guide/docs-style-guide.md

@@ -821,7 +821,7 @@ Here's an embedded live example for this guide. It has a custom image created fr
 
 <live-example embedded img="guide/docs-style-guide/docs-style-guide-plunker.png"></live-example>
 
-<a id="anchors"></a>
+{@a anchors}
 
 ## Anchors
 
@@ -861,7 +861,8 @@ Sometimes the section header text makes for an unattractive anchor. [This one](#
 
 The greater danger is that **a future rewording of the header text would break** a link to this section.
 
-For these reasons, it is often wise to add a custom anchor explicitly, just above the heading or text to which it applies, using the special`{@ name}` syntax like this.
+For these reasons, it is often wise to add a custom anchor explicitly, just above the heading or
+text to which it applies, using the special `{@a name}` syntax like this.
 
 <code-example  language="html">
   &#123;@a ugly-anchors&#125;

aio/content/guide/http.md

@@ -9,7 +9,7 @@ Additional benefits of `HttpClient` include testability support, strong typing o
 
 Before you can use the `HttpClient`, you need to install the `HttpClientModule` which provides it. This can be done in your application module, and is only necessary once.
 
-```javascript
+```typescript
 // app.module.ts:
 
 import {NgModule} from '@angular/core';
@@ -48,7 +48,7 @@ The most common type of request applications make to a backend is to request JSO
 The `get()` method on `HttpClient` makes accessing this data straightforward.
 
 
-```javascript
+```typescript
 @Component(...)
 export class MyComponent implements OnInit {
 
@@ -75,7 +75,7 @@ In the above example, the `data['results']` field access stands out because you
 You can, however, tell `HttpClient` what type the response will be, which is recommended.
 To do so, first you define an interface with the correct shape:
 
-```javascript
+```typescript
 interface ItemsResponse {
   results: string[];
 }
@@ -83,7 +83,7 @@ interface ItemsResponse {
 
 Then, when you make the `HttpClient.get` call, pass a type parameter:
 
-```javascript
+```typescript
 http.get<ItemsResponse>('/api/items').subscribe(data => {
   // data is now an instance of type ItemsResponse, so you can do this:
   this.results = data.results;
@@ -94,7 +94,7 @@ http.get<ItemsResponse>('/api/items').subscribe(data => {
 
 The response body doesn't return all the data you may need. Sometimes servers return special headers or status codes to indicate certain conditions, and inspecting those can be necessary. To do this, you can tell `HttpClient` you want the full response instead of just the body with the `observe` option:
 
-```javascript
+```typescript
 http
   .get<MyJsonData>('/data.json', {observe: 'response'})
   .subscribe(resp => {
@@ -116,7 +116,7 @@ What happens if the request fails on the server, or if a poor network connection
 
 To handle it, add an error handler to your `.subscribe()` call:
 
-```javascript
+```typescript
 http
   .get<ItemsResponse>('/api/items')
   .subscribe(
@@ -137,7 +137,7 @@ There are two types of errors that can occur. If the backend returns an unsucces
 
 In both cases, you can look at the `HttpErrorResponse` to figure out what happened.
 
-```javascript
+```typescript
 http
   .get<ItemsResponse>('/api/items')
   .subscribe(
@@ -169,7 +169,7 @@ import 'rxjs/add/operator/retry';
 
 Then, you can use it with HTTP Observables like this:
 
-```javascript
+```typescript
 http
   .get<ItemsResponse>('/api/items')
   // Retry this request up to 3 times.
@@ -182,7 +182,7 @@ http
 
 Not all APIs return JSON data. Suppose you want to read a text file on the server. You have to tell `HttpClient` that you expect a textual response:
 
-```javascript
+```typescript
 http
   .get('/textfile.txt', {responseType: 'text'})
   // The Observable returned by get() is of type Observable<string>
@@ -200,7 +200,7 @@ In addition to fetching data from the server, `HttpClient` supports mutating req
 One common operation is to POST data to a server; for example when submitting a form. The code for
 sending a POST request is very similar to the code for GET:
 
-```javascript
+```typescript
 const body = {name: 'Brad'};
 
 http
@@ -212,7 +212,7 @@ http
 
 *Note the `subscribe()` method.* All Observables returned from `HttpClient` are _cold_, which is to say that they are _blueprints_ for making requests. Nothing will happen until you call `subscribe()`, and every such call will make a separate request. For example, this code sends a POST request with the same data twice:
 
-```javascript
+```typescript
 const req = http.post('/api/items/add', body);
 // 0 requests made - .subscribe() not called.
 req.subscribe();
@@ -230,7 +230,7 @@ Besides the URL and a possible request body, there are other aspects of an outgo
 
 One common task is adding an `Authorization` header to outgoing requests. Here's how you do that:
 
-```javascript
+```typescript
 http
   .post('/api/items/add', body, {
     headers: new HttpHeaders().set('Authorization', 'my-auth-token'),
@@ -244,7 +244,7 @@ The `HttpHeaders` class is immutable, so every `set()` returns a new instance an
 
 Adding URL parameters works in the same way. To send a request with the `id` parameter set to `3`, you would do:
 
-```javascript
+```typescript
 http
   .post('/api/items/add', body, {
     params: new HttpParams().set('id', '3'),
@@ -269,7 +269,7 @@ before sending it to the server, and the interceptors can transform the response
 To implement an interceptor, you declare a class that implements `HttpInterceptor`, which
 has a single `intercept()` method. Here is a simple interceptor which does nothing but forward the request through without altering it:
 
-```javascript
+```typescript
 import {Injectable} from '@angular/core';
 import {HttpEvent, HttpInterceptor, HttpHandler, HttpRequest} from '@angular/common/http';
 
@@ -295,7 +295,7 @@ This pattern is similar to those in middleware frameworks such as Express.js.
 
 Simply declaring the `NoopInterceptor` above doesn't cause your app to use it. You need to wire it up in your app module by providing it as an interceptor, as follows:
 
-```javascript
+```typescript
 import {NgModule} from '@angular/core';
 import {HTTP_INTERCEPTORS} from '@angular/common/http';
 
@@ -338,7 +338,7 @@ If you have a need to mutate the request body, you need to copy the request body
 
 Since requests are immutable, they cannot be modified directly. To mutate them, use `clone()`:
 
-```javascript
+```typescript
 intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
   // This is a duplicate. It is exactly the same as the original.
   const dupReq = req.clone();
@@ -354,7 +354,7 @@ As you can see, the hash accepted by `clone()` allows you to mutate specific pro
 
 A common use of interceptors is to set default headers on outgoing responses. For example, assuming you have an injectable `AuthService` which can provide an authentication token, here is how you would write an interceptor which adds it to all outgoing requests:
 
-```javascript
+```typescript
 import {Injectable} from '@angular/core';
 import {HttpEvent, HttpInterceptor, HttpHandler, HttpRequest} from '@angular/common/http';
 
@@ -375,7 +375,7 @@ export class AuthInterceptor implements HttpInterceptor {
 
 The practice of cloning a request to set new headers is so common that there's actually a shortcut for it:
 
-```javascript
+```typescript
 const authReq = req.clone({setHeaders: {Authorization: authHeader}});
 ```
 
@@ -389,7 +389,7 @@ An interceptor that alters headers can be used for a number of different operati
 
 Because interceptors can process the request and response _together_, they can do things like log or time requests. Consider this interceptor which uses `console.log` to show how long each request takes:
 
-```javascript
+```typescript
 import 'rxjs/add/operator/do';
 
 export class TimingInterceptor implements HttpInterceptor {
@@ -414,7 +414,7 @@ Notice the RxJS `do()` operator&mdash;it adds a side effect to an Observable wit
 
 You can also use interceptors to implement caching. For this example, assume that you've written an HTTP cache with a simple interface:
 
-```javascript
+```typescript
 abstract class HttpCache {
   /**
    * Returns a cached response, if any, or null if not present.
@@ -430,7 +430,7 @@ abstract class HttpCache {
 
 An interceptor can apply this cache to outgoing requests.
 
-```javascript
+```typescript
 @Injectable()
 export class CachingInterceptor implements HttpInterceptor {
   constructor(private cache: HttpCache) {}
@@ -467,7 +467,7 @@ Obviously this example glosses over request matching, cache invalidation, etc.,
 
 To really demonstrate their flexibility, you can change the above example to return _two_ response events if the request exists in cache&mdash;the cached response first, and an updated network response later.
 
-```javascript
+```typescript
 intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
   // Still skip non-GET requests.
   if (req.method !== 'GET') {
@@ -507,7 +507,7 @@ Sometimes applications need to transfer large amounts of data, and those transfe
 
 To make a request with progress events enabled, first create an instance of `HttpRequest` with the special `reportProgress` option set:
 
-```javascript
+```typescript
 const req = new HttpRequest('POST', '/upload/file', file, {
   reportProgress: true,
 });
@@ -518,7 +518,7 @@ change detection, so only turn them on if you intend to actually update the UI o
 
 Next, make the request through the `request()` method of `HttpClient`. The result will be an Observable of events, just like with interceptors:
 
-```javascript
+```typescript
 http.request(req).subscribe(event => {
   // Via this API, you get access to the raw event stream.
   // Look for upload progress events.
@@ -553,7 +553,7 @@ In order to prevent collisions in environments where multiple Angular apps share
 
 If your backend service uses different names for the XSRF token cookie or header, use `HttpClientXsrfModule.withOptions()` to override the defaults.
 
-```javascript
+```typescript
 imports: [
   HttpClientModule,
   HttpClientXsrfModule.withOptions({
@@ -575,7 +575,7 @@ Angular's HTTP testing library is designed for a pattern of testing where the ap
 
 To begin testing requests made through `HttpClient`, import `HttpClientTestingModule` and add it to your `TestBed` setup, like so:
 
-```javascript
+```typescript
 
 import {HttpClientTestingModule} from '@angular/common/http/testing';
 
@@ -595,7 +595,7 @@ That's it. Now requests made in the course of your tests will hit the testing ba
 
 With the mock installed via the module, you can write a test that expects a GET Request to occur and provides a mock response. The following example does this by injecting both the `HttpClient` into the test and a class called `HttpTestingController`
 
-```javascript
+```typescript
 it('expects a GET request', inject([HttpClient, HttpTestingController], (http: HttpClient, httpMock: HttpTestingController) => {
   // Make an HTTP GET request, and expect that it return an object
   // of the form {name: 'Test Data'}.
@@ -624,7 +624,7 @@ it('expects a GET request', inject([HttpClient, HttpTestingController], (http: H
 
 The last step, verifying that no requests remain outstanding, is common enough for you to move it into an `afterEach()` step:
 
-```javascript
+```typescript
 afterEach(inject([HttpTestingController], (httpMock: HttpTestingController) => {
   httpMock.verify();
 }));
@@ -634,7 +634,7 @@ afterEach(inject([HttpTestingController], (httpMock: HttpTestingController) => {
 
 If matching by URL isn't sufficient, it's possible to implement your own matching function. For example, you could look for an outgoing request that has an Authorization header:
 
-```javascript
+```typescript
 const req = httpMock.expectOne((req) => req.headers.has('Authorization'));
 ```
 
@@ -644,7 +644,7 @@ Just as with the `expectOne()` by URL in the test above, if 0 or 2+ requests mat
 
 If you need to respond to duplicate requests in your test, use the `match()` API instead of `expectOne()`, which takes the same arguments but returns an array of matching requests. Once returned, these requests are removed from future matching and are your responsibility to verify and flush.
 
-```javascript
+```typescript
 // Expect that 5 pings have been made and flush them.
 const reqs = httpMock.match('/ping');
 expect(reqs.length).toBe(5);