Co-authored-by: unknown <deepanshu.9dd@gmail.com~>

`a expensive` should be `an expensive`

Fix "documentatino" typo to "documentation" in comment about useOptimistic reference page.

…d example of the use API (#7767)

* Update "Deep Dive" in reusing-logic-with-custom-hooks.md with link to and example of the use API

* Remove mention of Server Components when explaining the use API

* Update src/content/learn/reusing-logic-with-custom-hooks.md

Co-authored-by: Ricky <rickhanlonii@gmail.com>

* fix: Correct which lines are highlighted in code example

---------

Co-authored-by: Ricky <rickhanlonii@gmail.com>

The previous examples used a service called loremflickr.com to link to  placeholder images. Since that service is now down, I updated them to reference placecats.com instead, which we already use in other examples as well. placecats doesn't have the same random cat feature so I roughly approximated it in the example code.

Closes #7966

* Fix handleClick compiler intro example

* Use a note instead

* Update src/content/learn/react-compiler/introduction.md

* fix: changed source file names in docs from App.js, index.js and styles.css to src/ dir

* fix: updated wrong image with the correct one with current sandbox file structure

* refactor: reverted all formatting and just just mention src folder in introductory section

* Reverted changes tutorial-tic-tac-toe.md

* added enhanced image of sandbox

* docs: add flushSync Troubleshooting section

* Update src/content/reference/react-dom/flushSync.md

* oops

* Apply suggestions from code review

* formatting and pitfall

---------

Co-authored-by: Ricky <rickhanlonii@gmail.com>
Co-authored-by: Rick Hanlon <rickhanlonii@meta.com>

* correct IconExperimental naming and usage (from #7972)

Co-authored-by: Tuna <198469603+TunaDev0@users.noreply.github.com>

* Bump Activity to Canary in docs

---------

Co-authored-by: Tuna <198469603+TunaDev0@users.noreply.github.com>

Happened to notice we were still on an old version of the compiler. This PR upgrades us to use the latest RC.

Copied over our copyright script from the react repo. I made a small fix to handle shebangs.

* Add copyright script

Copied over our copyright script from the react repo. I made a small fix to handle shebangs.

* Update copyright on all files

Run the script.

…iler (#7988)

In facebook/react#34462 for example, we found an issue where the compiler was incorrectly validating an example straight from the docs.

In order to find more issues like this + also provide more feedback to doc authors on valid/invalid patterns, this PR adds a new local eslint rule which validates all markdown codeblocks containing components/hooks with React Compiler. An autofixer is also provided.

To express that a codeblock has an expected error, we can use the following metadata:

```ts
// pseudo type def
type MarkdownCodeBlockMetadata = {
    expectedErrors?: {
      'react-compiler'?: number[];
    };
  };
```

and can be used like so:

````
```js {expectedErrors: {'react-compiler': [4]}}
// ❌ setState directly in render
function Component({value}) {
  const [count, setCount] = useState(0);
  setCount(value); // error on L4
  return <div>{count}</div>;
}
```
````

Because this is defined as a local rule, we don't have the same granular reporting that `eslint-plugin-react-hooks` yet. I can look into that later but for now this first PR just sets us up with something basic.

* Add local eslint rule to validate markdown codeblocks with React Compiler

In facebook/react#34462 for example, we found an issue where the compiler was incorrectly validating an example straight from the docs.

In order to find more issues like this + also provide more feedback to doc authors on valid/invalid patterns, this PR adds a new local eslint rule which validates all markdown codeblocks containing components/hooks with React Compiler. An autofixer is also provided.

To express that a codeblock has an expected error, we can use the following metadata:

```ts
// pseudo type def
type MarkdownCodeBlockMetadata = {
    expectedErrors?: {
      'react-compiler'?: number[];
    };
  };
```

and can be used like so:

````
```js {expectedErrors: {'react-compiler': [4]}}
// ❌ setState directly in render
function Component({value}) {
  const [count, setCount] = useState(0);
  setCount(value); // error on L4
  return <div>{count}</div>;
}
```
````

Because this is defined as a local rule, we don't have the same granular reporting that `eslint-plugin-react-hooks` yet. I can look into that later but for now this first PR just sets us up with something basic.

* fix compiler errors

I went through the list of existing errors and tried to separate the expected errors from those that seem to be flagging unexpected issues.  In particular, our effects validations are flagging patterns that our own docs examples use. I added todos for these and will follow up later.

Previously, `createFileMap` split the MDX meta string on spaces and assumed the first token was the filename. Once we prefixed code fences with `{expectedErrors: ...}`, it would incorrectly parse the meta and crash.

This PR updates createFileMap to skip tokens in the meta containing a start and end brace pair (using a stack to ensure we close on the correct brace) while tokenizing the meta string as expected.

Test plan: pages reported in #7994 no longer crash on the next PR

Closes #7994

For local dev and CI we want to have the eslint-local-rules running, so let's make sure both have their dependencies installed. We don't use a monorepo setup here, which is why they're currently setup as a two completely independent yarn workspaces.

Adds new docs for our new eslint rules.