This PR greatly improves the types within Puppeteer:
- **Almost everything** is auto-deduced.
- Parameters don't need to be specified in the function. They are deduced from the spread.
- Return types don't need to be specified. They are deduced from the function. (More on this below)
- Selections based on tag names correctly deduce element type, similar to TypeScript's mechanism for `getElementByTagName`.
- [**BREAKING CHANGE**] We've removed the ability to declare return types in type arguments for the following reasons:
1. Setting them will indubitably break auto-deduction.
2. You can just use `as ...` in TypeScript to coerce the correct type (given it makes sense).
- [**BREAKING CHANGE**] `waitFor` is officially gone.
To migrate to these changes, there are only four things you may need to change:
- If you set a return type using the `ReturnType` type parameter, remove it and use `as ...` and `HandleFor` (if necessary).
⛔ `evaluate<ReturnType>(a: number, b: number) => {...}, a, b)`
✅ `(await evaluate(a, b) => {...}, a, b)) as ReturnType`
⛔ `evaluateHandle<ReturnType>(a: number, b: number) => {...}, a, b)`
✅ `(await evaluateHandle(a, b) => {...}, a, b)) as HandleFor<ReturnType>`
- If you set any type parameters in the *parameters* of an evaluation function, remove them.
⛔ `evaluate(a: number, b: number) => {...}, a, b)`
✅ `evaluate(a, b) => {...}, a, b)`
- If you set any type parameters in the method's declaration, remove them.
⛔ `evaluate<(a: number, b: number) => void>((a, b) => {...}, a, b)`
✅ `evaluate(a, b) => {...}, a, b)`
We're seeing odd failures with Prettier on some CI branches; my hunch is that they are installing different versions of the package and therefore getting formatting conflicts. This PR updates them all and pins them to specific versions - something we should probably consider generally, or remove our `package-lock.json` from the gitignore.
* chore: enforce file extensions on imports
To make our output agnostic it should include file extensions in the
output, as per the ESM spec. It's a bit odd for Node packages but makes
it easier to publish a browser build.
* chore: Use devtools-protocol package
Rather than maintain our own protocol we can instead use the devtools-protocol package and pin it to the version of Chromium that Puppeteer is shipping with.
The only changes are naming changes between the bespoke protocol that Puppeteer created and the devtools-protocol one.
This change started as a small change to pull types from DefinitelyTyped over to
Puppeteer for the `evaluateHandle` function but instead ended up also fixing
what looks to be a long standing issue with our existing documentation.
`evaluateHandle` can in fact return an `ElementHandle` rather than a `JSHandle`.
Note that `ElementHandle` extends `JSHandle` so whilst the docs are technically
correct (all ElementHandles are JSHandles) it's confusing because JSHandles
don't have methods like `click` on them, but ElementHandles do.
if you return something that is an HTML element:
```
const button = page.evaluateHandle(() => document.querySelector('button'));
// this is an ElementHandle, not a JSHandle
```
Therefore I've updated the original docs and added a large explanation to the
TSDoc for `page.evaluateHandle`.
In TypeScript land we'll assume the function will return a `JSHandle` but you
can tell TS otherwise via the generic argument, which can only be `JSHandle`
(the default) or `ElementHandle`:
```
const button = page.evaluateHandle<ElementHandle>(() => document.querySelector('button'));
```
These files will be used by both the web and node versions of Puppeteer.
Another name for this might be "core" but I don't want to cause
confusion with the puppeteer-core package that we publish at the moment.
