**Unit Testing Code Does Not Compile**
The compilation error is:
```
The compilation error is
./src/testing/http-client.spec.ts - Error: Module build failed (from ./node_modules/@ngtools/webpack/src/ivy/index.js):
Error: /home/projects/obk3vc--run/src/testing/http-client.spec.ts is missing from the TypeScript compilation. Please make sure it is in your tsconfig via the 'files' or 'include' property.
```
I’m not sure what to say about unit testing HTTP in a full Standalone app. Is it different?
_This is the only known remaining defect in this conversion of HTTP to Standalone._
**Edited content of `http-request-data-from-server.md`**
The current version of this page is confusing. In particular
* It tells readers they **should always unsubscribe** from the HttpClient method calls. This is *not true* and this example doesn't even do it. I replaced this instruction with more nuanced advice and an explanation of why it is OK to not unsubscribe to HttpClient methods.
* There is a "helpful" note about using the RxJS `map` operator to transform the response. This is *not "helpfulf"*. It is *confusing* because the sample doesn't use `map` anywhere. It was unnecessary here, even if it might be helpful elsewhere. I removed this note.
* The "Requesting a typed response" section seemed unclear to me, particularly because the guide begins with a `get` request that already has the `Config` return type specification. My revision attempts to make this more clear.
* The bold "callout" about the `observe` and `responseType` options appears out of nowhere after "Requesting a typed response". It's disconcerting at best. I moved it to the bottom of the page and linked to it from the `options` discussion at the top.
I made a few other revisions that I hope improve the readability of this page.
**Corrected `http-make-jsonp-request.md`**
The JSONP example, handwritten in the guide page, would not have compiled. I added one that does to `heroes.service.ts` and displayed it on this page.
**Corrected `http-handle-request-errors.md`
This page ended with a section called "Sending data to a server" that introduces PUT, POST, and DELETE. These features have nothing to do with error handling and the verbiage here duplicates the opening paragraphs of the next topic which does: "Send data to a server". So I deleted this section from the error handling guide page.
**Archived http-setup-server-communication.md**
`http-setup-server-communication.md` appears to be the original long document that has since been divided over the other pages in this folder.
It shouldn’t be in the reader’s flow. I did update it for Standalone. But I also removed it from left-nav and marked as archived.
PR Close#51400
**Pipes Sample Code**
Migrated all sample code in the `examples/pipes` folder. Did not touch the pipes in the ToH or Testing folders.
>The existing, complex discussion of the `CurrencyPipe` within `pipes-transform-data.md` cried out for a new `concurrency-formatting.component` example`.
**Extracted "pipe precedence" into its own page**
The topic had been extracted from `pipe.md` and tacked on to the bottom of the `pipes-overview.md` page.
It's an advanced and somewhat obscure topic that doesn't belong in the overview. Rather than throw it away, I created a new `pipe-precedence.md` page and added it to the bottom of the pipes section navigation.
I also tried to improve both the guide text and the companion component, `precedence.component`.
**How to create a pipe is missing**
The readers are told they can create their own pipes in several places throughout the docs. But there are no links and you can't navigate to a page that covers the topic. This is a serious omission!
The topic is introduced in the `pipes-custom-data-trans.md` page (extracted verbatim from `pipes.md`). But you can't navigate to this page and their are no links to it.
TODO: restore this page and add it to the left-nav.
**Change `pipes.md` references to `pipe-overview.md`**
The original, kitchen-sink page, `pipes.md`, was disconnected from navigation long ago, in favor of multiple pages such as `pipe-overview.md`. The page is still in the AIO documentation and can be found by searching or by links from 3rd party documenters. Landing on that page hides the left-nav.
In this commit, we treat `pipes.md` as deprecated (which it seems to be). Therefore, this commit retargets previous `pipes.md` references to `pipe-overview.md`.
>The `change-detection-slow-computations.md` is the exception. It refers to "pure pipes", a subject not covered in the current pipe documentation. That reference is retargeted to `api/core/Pipe#pure`.
Certain code files are only referenced in `pipe.md`. They still work and are displayed in the overall pipes code sample as before. Now they are marked with deprecation comments for future treatment or removal.
For consistency, certain sections of `pipes.md` were replaced by the contents of the corresponding current pages.
PR Close#51333
