* Add typescript as a valid parser value
Now that typescript development has started, each contributor has been adding this as a supported flag themselves.
This just adds it as an allowed option, with a warning that support for this parser is experimental.
I also tried to structure this a bit future proof, in case other experimental parsers come along.
* Simplifies the code at vjeux's request
Rather than a notion of "experimental" parsers, we'll just leave typescript out of the documentation until it's supported.
We've had this issue since the beginning and I tagged it as 1.0 but haven't managed to fix it by then. We shouldn't allow things to break in the argument list if we are in the last argument expansion mode. It turns out that we now have all the building blocks needed to fix this:
- have a special way to flag when we are printing the last argument expansion in the code that prints the argument list
- have a way to remove all the softlines from the argument list
Fixes#1301
This is the second part of the fix for the performance regression seen in #1250. In #1217, for correctness reasons, we're now traversing all the conditional groups. This means that we're now in O(n^2). But, in practice, many of those groups are === between each others. So we only need to recurse through one of the instances to know if it's going to break.
This makes the first example go from not terminating to being instant. The second one going from not terminating to taking ~1s. We can also make it instant by tweaking the printing phase, but that's for another PR.
In #1250, @jeresig reported that adding // prettier-ignore on a file that has a ton of conditional group still took 1.7s. The issue is that we're printing before checking for the comment. Swaping the two had the unfortunate side effect of not marking the comments as being printed, so I had to skip that safety check if there's a prettier-ignore.
With this change, adding prettier-ignore makes the file be printed instantly!
The implementation was checking if the comment was inside of the expression range, which seems like a good idea. Unfortunately, the expression range is not what's inside of `${}` but the actual AST node, which incidentally doesn't include comments. So the logic was off and returned `undefined` which threw afterwards.
Another solution is to find the first quasi where start is > comment start. This means that the comment appeared between the quasi before and this one... therefore in the expression before!
The flow parser has issues with unicode where it makes node location invalid, there are likely other places where node locations are off. So instead of throwing with a weird error, let's attach it to the first one if it doesn't work.
Fixes#1293
As I was debugging #1248, I found out that the code to fix was actually making things worse. The other two branches are for decorators and deleting some random value of a function. I ran all the tests and the flow object is actually now preserving empty lines and didn't change anything else.
I'd rather remove all those and if something comes up then fix it properly upstream than having those crutches that we don't know why they exist anymore.
In #1257, I discovered that if there's a `""` doc at the end, it's not going to trim the previous one correctly. It also happens to fix a few existing things.
This one is pretty crazy. In #927, I changed
```js
concat(["(", join(concat([", "]), printed), ")"]),
```
into
```js
concat(["(", join(concat([", "]), printedLastArgExpanded), ")"]),
```
which makes the example in #1203 look ugly. The crazy thing is that `JSON.stringify(printed) === JSON.stringify(printedLastArgExpanded)`. So they are deep equal but not the same object. In a non-mutative world, this should cause any problem, but we actually mutate those to propagate breaks.
In the break propagation, we only looked at the first one in case of a conditional group. But, because the two were the same object then it also applied to the second one and happened to be the correct behavior! When I changed that piece of code to be two distinct objects, it no longer worked by accident and caused a bunch of weird issues where breaks didn't propagate correctly.
The solution for this case is to propagate the breaks on all the conditions. I'm pretty sure that this is the expected behavior, we want to deeply recurse in all of them, we don't propagate it up the boundary anyway.
The other use case for `traverseInDoc()` is `findInDoc()`, right now it searches for the first conditional group but it seems very arbitrary. I changed it to not search on any and none of the tests are failing, so I think it's safe(tm). If it triggers weird behavior, then it'll at least be expected and not randomly explode at us if we move groups around.
I tried to go through all the conditions for `findInDoc()` but it triggers a few failures (the output look bad). I'm not really sure why. https://gist.github.com/vjeux/5fb7566cc3d65974817d512d1ef6abe1Fix#1203
We shouldn't be reading from the printed document but instead look at the AST. This was really easy, it can either be EmptyStatement, BlockStatement or anything else.
In #847, I used a heuristic to find if the element was going to be expanded. But, it wasn't 100% accurate because we couldn't know in which conditionalGroup we would land. We added a way for the parent to tell that function if we should be in `expandLastArg`. By replacing the condition by this variable, it now fixes the issues!
This is so good that adding the right abstraction fixes problems across the board :)
Fixes#997
Christopher Chedeau