## Summary
This PR updates the native server to consider the `include` and
`extend-include` file resolver settings.
fixes: #12242
## Test Plan
Note: Settings reloading doesn't work for nested configs which is fixed
in #12253 so the preview here only showcases root level config.
e8969128-c175-4f98-8114-0d692b906cc8
## Summary
This PR removes the need to check for `E999` code to find the diagnostic
severity in the server.
**Note:** This is just removing a redundant check because all
`ParseErrors` are converted to `Diagnostic` with default `Error`
severity by
63c92586a1/crates/ruff_server/src/lint.rs (L309-L346)
## Test Plan
Verify that syntax errors are still shown with error severity as it did
before:
<img width="1313" alt="Screenshot 2024-06-28 at 09 30 20"
src="75e389a7-01ea-461c-86a2-0dfc244e515d">
## Summary
Follow-up from #11901
This PR adds a new server setting to show / hide syntax errors.
## Test Plan
### VS Code
Using https://github.com/astral-sh/ruff-vscode/pull/504 with the
following config:
```json
{
"ruff.nativeServer": true,
"ruff.path": ["/Users/dhruv/work/astral/ruff/target/debug/ruff"],
"ruff.showSyntaxErrors": true
}
```
First, set `ruff.showSyntaxErrors` to `true`:
<img width="1177" alt="Screenshot 2024-06-27 at 08 34 58"
src="5d77547a-a908-4a00-8714-7c00784e8679">
And then set it to `false`:
<img width="1185" alt="Screenshot 2024-06-27 at 08 35 19"
src="9720f089-f10c-420b-a2c1-2bbb2245be35">
### Neovim
Using the following Ruff server config:
```lua
require('lspconfig').ruff.setup {
init_options = {
settings = {
showSyntaxErrors = false,
},
},
}
```
First, set `showSyntaxErrors` to `true`:
<img width="1279" alt="Screenshot 2024-06-27 at 08 28 03"
src="e694e231-91ba-47f8-8e8a-ad2e82b85a45">
And then set it to `false`:
<img width="1284" alt="Screenshot 2024-06-27 at 08 28 20"
src="25b86a57-02b1-44f7-9f65-cf5fdde93b0c">
## Summary
Follow-up to #11902
This PR simplifies the `LinterResult` struct by avoiding the generic and
not store the `ParseError`.
This is possible because the callers already have access to the
`ParseError` via the `Parsed` output. This also means that we can
simplify the return type of `check_path` and avoid the generic `T` on
`LinterResult`.
## Test Plan
`cargo insta test`
## Summary
This PR updates the way syntax errors are handled throughout the linter.
The main change is that it's now not considered as a rule which involves
the following changes:
* Update `Message` to be an enum with two variants - one for diagnostic
message and the other for syntax error message
* Provide methods on the new message enum to query information required
by downstream usages
This means that the syntax errors cannot be hidden / disabled via any
disablement methods. These are:
1. Configuration via `select`, `ignore`, `per-file-ignores`, and their
`extend-*` variants
```console
$ cargo run -- check ~/playground/ruff/src/lsp.py --extend-select=E999
--no-preview --no-cache
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.10s
Running `target/debug/ruff check /Users/dhruv/playground/ruff/src/lsp.py
--extend-select=E999 --no-preview --no-cache`
warning: Rule `E999` is deprecated and will be removed in a future
release. Syntax errors will always be shown regardless of whether this
rule is selected or not.
/Users/dhruv/playground/ruff/src/lsp.py:1:8: F401 [*] `abc` imported but
unused
|
1 | import abc
| ^^^ F401
2 | from pathlib import Path
3 | import os
|
= help: Remove unused import: `abc`
```
3. Command-line flags via `--select`, `--ignore`, `--per-file-ignores`,
and their `--extend-*` variants
```console
$ cargo run -- check ~/playground/ruff/src/lsp.py --no-cache
--config=~/playground/ruff/pyproject.toml
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.11s
Running `target/debug/ruff check /Users/dhruv/playground/ruff/src/lsp.py
--no-cache --config=/Users/dhruv/playground/ruff/pyproject.toml`
warning: Rule `E999` is deprecated and will be removed in a future
release. Syntax errors will always be shown regardless of whether this
rule is selected or not.
/Users/dhruv/playground/ruff/src/lsp.py:1:8: F401 [*] `abc` imported but
unused
|
1 | import abc
| ^^^ F401
2 | from pathlib import Path
3 | import os
|
= help: Remove unused import: `abc`
```
This also means that the **output format** needs to be updated:
1. The `code`, `noqa_row`, `url` fields in the JSON output is optional
(`null` for syntax errors)
2. Other formats are changed accordingly
For each format, a new test case specific to syntax errors have been
added. Please refer to the snapshot output for the exact format for
syntax error message.
The output of the `--statistics` flag will have a blank entry for syntax
errors:
```
315 F821 [ ] undefined-name
119 [ ] syntax-error
103 F811 [ ] redefined-while-unused
```
The **language server** is updated to consider the syntax errors by
convert them into LSP diagnostic format separately.
### Preview
There are no quick fixes provided to disable syntax errors. This will
automatically work for `ruff-lsp` because the `noqa_row` field will be
`null` in that case.
<img width="772" alt="Screenshot 2024-06-26 at 14 57 08"
src="aaac827e-4777-4ac8-8c68-eaf9f2c36774">
Even with `noqa` comment, the syntax error is displayed:
<img width="763" alt="Screenshot 2024-06-26 at 14 59 51"
src="ba1afb68-7eaf-4b44-91af-6d93246475e2">
Rule documentation page:
<img width="1371" alt="Screenshot 2024-06-26 at 16 48 07"
src="524f01df-d91f-4ac0-86cc-40e76b318b24">
## Test Plan
- [x] Disablement methods via config shows a warning
- [x] `select`, `extend-select`
- [ ] ~`ignore`~ _doesn't show any message_
- [ ] ~`per-file-ignores`, `extend-per-file-ignores`~ _doesn't show any
message_
- [x] Disablement methods via command-line flag shows a warning
- [x] `--select`, `--extend-select`
- [ ] ~`--ignore`~ _doesn't show any message_
- [ ] ~`--per-file-ignores`, `--extend-per-file-ignores`~ _doesn't show
any message_
- [x] File with syntax errors should exit with code 1
- [x] Language server
- [x] Should show diagnostics for syntax errors
- [x] Should not recommend a quick fix edit for adding `noqa` comment
- [x] Same for `ruff-lsp`
resolves: #8447
## Summary
This PR updates the parser to remove building the `CommentRanges` and
instead it'll be built by the linter and the formatter when it's
required.
For the linter, it'll be built and owned by the `Indexer` while for the
formatter it'll be built from the `Tokens` struct and passed as an
argument.
## Test Plan
`cargo insta test`
## Summary
As-is, we're using the URL path for all files, leading us to use paths
like:
```
/c%3A/Users/crmar/workspace/fastapi/tests/main.py
```
This doesn't match against per-file ignores and other patterns in Ruff
configuration.
This PR modifies the LSP to use the real file path if available, and the
virtual file path if not.
Closes https://github.com/astral-sh/ruff/issues/11751.
## Test Plan
Ran the LSP on Windows. In the FastAPI repo, added:
```toml
[tool.ruff.lint.per-file-ignores]
"tests/**/*.py" = ["F401"]
```
And verified that an unused import was ignored in `tests` after this
change, but not before.
## Summary
This PR updates the entire parser stack in multiple ways:
### Make the lexer lazy
* https://github.com/astral-sh/ruff/pull/11244
* https://github.com/astral-sh/ruff/pull/11473
Previously, Ruff's lexer would act as an iterator. The parser would
collect all the tokens in a vector first and then process the tokens to
create the syntax tree.
The first task in this project is to update the entire parsing flow to
make the lexer lazy. This includes the `Lexer`, `TokenSource`, and
`Parser`. For context, the `TokenSource` is a wrapper around the `Lexer`
to filter out the trivia tokens[^1]. Now, the parser will ask the token
source to get the next token and only then the lexer will continue and
emit the token. This means that the lexer needs to be aware of the
"current" token. When the `next_token` is called, the current token will
be updated with the newly lexed token.
The main motivation to make the lexer lazy is to allow re-lexing a token
in a different context. This is going to be really useful to make the
parser error resilience. For example, currently the emitted tokens
remains the same even if the parser can recover from an unclosed
parenthesis. This is important because the lexer emits a
`NonLogicalNewline` in parenthesized context while a normal `Newline` in
non-parenthesized context. This different kinds of newline is also used
to emit the indentation tokens which is important for the parser as it's
used to determine the start and end of a block.
Additionally, this allows us to implement the following functionalities:
1. Checkpoint - rewind infrastructure: The idea here is to create a
checkpoint and continue lexing. At a later point, this checkpoint can be
used to rewind the lexer back to the provided checkpoint.
2. Remove the `SoftKeywordTransformer` and instead use lookahead or
speculative parsing to determine whether a soft keyword is a keyword or
an identifier
3. Remove the `Tok` enum. The `Tok` enum represents the tokens emitted
by the lexer but it contains owned data which makes it expensive to
clone. The new `TokenKind` enum just represents the type of token which
is very cheap.
This brings up a question as to how will the parser get the owned value
which was stored on `Tok`. This will be solved by introducing a new
`TokenValue` enum which only contains a subset of token kinds which has
the owned value. This is stored on the lexer and is requested by the
parser when it wants to process the data. For example:
8196720f80/crates/ruff_python_parser/src/parser/expression.rs (L1260-L1262)
[^1]: Trivia tokens are `NonLogicalNewline` and `Comment`
### Remove `SoftKeywordTransformer`
* https://github.com/astral-sh/ruff/pull/11441
* https://github.com/astral-sh/ruff/pull/11459
* https://github.com/astral-sh/ruff/pull/11442
* https://github.com/astral-sh/ruff/pull/11443
* https://github.com/astral-sh/ruff/pull/11474
For context,
https://github.com/RustPython/RustPython/pull/4519/files#diff-5de40045e78e794aa5ab0b8aacf531aa477daf826d31ca129467703855408220
added support for soft keywords in the parser which uses infinite
lookahead to classify a soft keyword as a keyword or an identifier. This
is a brilliant idea as it basically wraps the existing Lexer and works
on top of it which means that the logic for lexing and re-lexing a soft
keyword remains separate. The change here is to remove
`SoftKeywordTransformer` and let the parser determine this based on
context, lookahead and speculative parsing.
* **Context:** The transformer needs to know the position of the lexer
between it being at a statement position or a simple statement position.
This is because a `match` token starts a compound statement while a
`type` token starts a simple statement. **The parser already knows
this.**
* **Lookahead:** Now that the parser knows the context it can perform
lookahead of up to two tokens to classify the soft keyword. The logic
for this is mentioned in the PR implementing it for `type` and `match
soft keyword.
* **Speculative parsing:** This is where the checkpoint - rewind
infrastructure helps. For `match` soft keyword, there are certain cases
for which we can't classify based on lookahead. The idea here is to
create a checkpoint and keep parsing. Based on whether the parsing was
successful and what tokens are ahead we can classify the remaining
cases. Refer to #11443 for more details.
If the soft keyword is being parsed in an identifier context, it'll be
converted to an identifier and the emitted token will be updated as
well. Refer
8196720f80/crates/ruff_python_parser/src/parser/expression.rs (L487-L491).
The `case` soft keyword doesn't require any special handling because
it'll be a keyword only in the context of a match statement.
### Update the parser API
* https://github.com/astral-sh/ruff/pull/11494
* https://github.com/astral-sh/ruff/pull/11505
Now that the lexer is in sync with the parser, and the parser helps to
determine whether a soft keyword is a keyword or an identifier, the
lexer cannot be used on its own. The reason being that it's not
sensitive to the context (which is correct). This means that the parser
API needs to be updated to not allow any access to the lexer.
Previously, there were multiple ways to parse the source code:
1. Passing the source code itself
2. Or, passing the tokens
Now that the lexer and parser are working together, the API
corresponding to (2) cannot exists. The final API is mentioned in this
PR description: https://github.com/astral-sh/ruff/pull/11494.
### Refactor the downstream tools (linter and formatter)
* https://github.com/astral-sh/ruff/pull/11511
* https://github.com/astral-sh/ruff/pull/11515
* https://github.com/astral-sh/ruff/pull/11529
* https://github.com/astral-sh/ruff/pull/11562
* https://github.com/astral-sh/ruff/pull/11592
And, the final set of changes involves updating all references of the
lexer and `Tok` enum. This was done in two-parts:
1. Update all the references in a way that doesn't require any changes
from this PR i.e., it can be done independently
* https://github.com/astral-sh/ruff/pull/11402
* https://github.com/astral-sh/ruff/pull/11406
* https://github.com/astral-sh/ruff/pull/11418
* https://github.com/astral-sh/ruff/pull/11419
* https://github.com/astral-sh/ruff/pull/11420
* https://github.com/astral-sh/ruff/pull/11424
2. Update all the remaining references to use the changes made in this
PR
For (2), there were various strategies used:
1. Introduce a new `Tokens` struct which wraps the token vector and add
methods to query a certain subset of tokens. These includes:
1. `up_to_first_unknown` which replaces the `tokenize` function
2. `in_range` and `after` which replaces the `lex_starts_at` function
where the former returns the tokens within the given range while the
latter returns all the tokens after the given offset
2. Introduce a new `TokenFlags` which is a set of flags to query certain
information from a token. Currently, this information is only limited to
any string type token but can be expanded to include other information
in the future as needed. https://github.com/astral-sh/ruff/pull/11578
3. Move the `CommentRanges` to the parsed output because this
information is common to both the linter and the formatter. This removes
the need for `tokens_and_ranges` function.
## Test Plan
- [x] Update and verify the test snapshots
- [x] Make sure the entire test suite is passing
- [x] Make sure there are no changes in the ecosystem checks
- [x] Run the fuzzer on the parser
- [x] Run this change on dozens of open-source projects
### Running this change on dozens of open-source projects
Refer to the PR description to get the list of open source projects used
for testing.
Now, the following tests were done between `main` and this branch:
1. Compare the output of `--select=E999` (syntax errors)
2. Compare the output of default rule selection
3. Compare the output of `--select=ALL`
**Conclusion: all output were same**
## What's next?
The next step is to introduce re-lexing logic and update the parser to
feed the recovery information to the lexer so that it can emit the
correct token. This moves us one step closer to having error resilience
in the parser and provides Ruff the possibility to lint even if the
source code contains syntax errors.
## Summary
Closes https://github.com/astral-sh/ruff/issues/11587.
## Test Plan
- Added a lint error to `test_server.py` in `vscode-ruff`.
- Validated that, prior to this change, diagnostics appeared in the
file.
- Validated that, with this change, no diagnostics were shown.
- Validated that, with this change, no diagnostics were fixed on-save.
## Summary
Fixes https://github.com/astral-sh/ruff/issues/11236.
This PR fixes several issues, most of which relate to non-VS Code
editors (Helix and Neovim).
1. Global-only initialization options are now correctly deserialized
from Neovim and Helix
2. Empty diagnostics are now published correctly for Neovim and Helix.
3. A workspace folder is created at the current working directory if the
initialization parameters send an empty list of workspace folders.
4. The server now gracefully handles opening files outside of any known
workspace, and will use global fallback settings taken from client
editor settings and a user settings TOML, if it exists.
## Test Plan
I've tested to confirm that each issue has been fixed.
* Global-only initialization options are now correctly deserialized from
Neovim and Helix + the server gracefully handles opening files outside
of any known workspace
4f33477f-20c8-4e50-8214-6608b1a1ea6b
* Empty diagnostics are now published correctly for Neovim and Helix
c93f56a0-f75d-466f-9f40-d77f99cf0637
* A workspace folder is created at the current working directory if the
initialization parameters send an empty list of workspace folders.
b4b2e818-4b0d-40ce-961d-5831478cc726
## Summary
Closes https://github.com/astral-sh/ruff/issues/10858.
`ruff server` now supports `*.ipynb` (aka Jupyter Notebook) files.
Extensive internal changes have been made to facilitate this, which I've
done some work to contextualize with documentation and an pre-review
that highlights notable sections of the code.
`*.ipynb` cells should behave similarly to `*.py` documents, with one
major exception. The format command `ruff.applyFormat` will only apply
to the currently selected notebook cell - if you want to format an
entire notebook document, use `Format Notebook` from the VS Code context
menu.
## Test Plan
The VS Code extension does not yet have Jupyter Notebook support
enabled, so you'll first need to enable it manually. To do this,
checkout the `pre-release` branch and modify `src/common/server.ts` as
follows:
Before:
After:
I recommend testing this PR with large, complicated notebook files. I
used notebook files from [this popular
repository](https://github.com/jakevdp/PythonDataScienceHandbook/tree/master/notebooks)
in my preliminary testing.
The main thing to test is ensuring that notebook cells behave the same
as Python documents, besides the aforementioned issue with
`ruff.applyFormat`. You should also test adding and deleting cells (in
particular, deleting all the code cells and ensure that doesn't break
anything), changing the kind of a cell (i.e. from markup -> code or vice
versa), and creating a new notebook file from scratch. Finally, you
should also test that source actions work as expected (and across the
entire notebook).
Note: `ruff.applyAutofix` and `ruff.applyOrganizeImports` are currently
broken for notebook files, and I suspect it has something to do with
https://github.com/astral-sh/ruff/issues/11248. Once this is fixed, I
will update the test plan accordingly.
---------
Co-authored-by: nolan <nolan.king90@gmail.com>
## Summary
Alternative to #11237
This PR adds a new `Tokens` struct which is a newtype wrapper around a
vector of lexer output. This allows us to add a `kinds` method which
returns an iterator over the corresponding `TokenKind`. This iterator is
implemented as a separate `TokenKindIter` struct to allow using the type
and provide additional methods like `peek` directly on the iterator.
This exposes the linter to access the stream of `TokenKind` instead of
`Tok`.
Edit: I've made the necessary downstream changes and plan to merge the
entire stack at once.
## Summary
Fixes https://github.com/astral-sh/ruff/issues/10594.
Code actions to disable a diagnostic via `noqa` comment are now
available.
6d3bcf11-a9d9-499b-8c7f-a10cd39cfbba
`DiagnosticFix` has been changed so that `noqa` code actions appear even
for diagnostics with no available quick fix. It can contain quick fix
edits, `noqa` comment edits, or both.
## Test Plan
The scenarios that need to be tested are as follows:
* A code action to disable a diagnostic should be available for every
diagnostic.
* Using this code action should append to the appropriate line with the
diagnostic, or modify an existing `noqa` comment.
* Adding a `noqa` comment manually should make a diagnostic disappear
* `Fix all auto-fixable problems` should not add `noqa` comments
* Removing a code from a `noqa` comment should make the diagnostic
re-appear
## Summary
This PR removes the `ImportMap` implementation and all its routing
through ruff.
The import map was added in https://github.com/astral-sh/ruff/pull/3243
but we then never ended up using it to do cross file analysis.
We are now working on adding multifile analysis to ruff, and revisit
import resolution as part of it.
```
hyperfine --warmup 10 --runs 20 --setup "./target/release/ruff clean" \
"./target/release/ruff check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I" \
"./target/release/ruff-import check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I"
Benchmark 1: ./target/release/ruff check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I
Time (mean ± σ): 37.6 ms ± 0.9 ms [User: 52.2 ms, System: 63.7 ms]
Range (min … max): 35.8 ms … 39.8 ms 20 runs
Benchmark 2: ./target/release/ruff-import check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I
Time (mean ± σ): 36.0 ms ± 0.7 ms [User: 50.3 ms, System: 58.4 ms]
Range (min … max): 34.5 ms … 37.6 ms 20 runs
Summary
./target/release/ruff-import check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I ran
1.04 ± 0.03 times faster than ./target/release/ruff check crates/ruff_linter/resources/test/cpython -e -s --extend-select=I
```
I suspect that the performance improvement should even be more
significant for users that otherwise don't have any diagnostics.
```
hyperfine --warmup 10 --runs 20 --setup "cd ../ecosystem/airflow && ../../ruff/target/release/ruff clean" \
"./target/release/ruff check ../ecosystem/airflow -e -s --extend-select=I" \
"./target/release/ruff-import check ../ecosystem/airflow -e -s --extend-select=I"
Benchmark 1: ./target/release/ruff check ../ecosystem/airflow -e -s --extend-select=I
Time (mean ± σ): 53.7 ms ± 1.8 ms [User: 68.4 ms, System: 63.0 ms]
Range (min … max): 51.1 ms … 58.7 ms 20 runs
Benchmark 2: ./target/release/ruff-import check ../ecosystem/airflow -e -s --extend-select=I
Time (mean ± σ): 50.8 ms ± 1.4 ms [User: 50.7 ms, System: 60.9 ms]
Range (min … max): 48.5 ms … 55.3 ms 20 runs
Summary
./target/release/ruff-import check ../ecosystem/airflow -e -s --extend-select=I ran
1.06 ± 0.05 times faster than ./target/release/ruff check ../ecosystem/airflow -e -s --extend-select=I
```
## Test Plan
`cargo test`
## Summary
Fixes#11185Fixes#11214
Document path and package information is now forwarded to the Ruff
linter, which allows `per-file-ignores` to correctly match against the
file name. This also fixes an issue where the import sorting rule didn't
distinguish between third-party and first-party packages since we didn't
pass in the package root.
## Test Plan
`per-file-ignores` should ignore files as expected. One quick way to
check is by adding this to your `pyproject.toml`:
```toml
[tool.ruff.lint.per-file-ignores]
"__init__.py" = ["ALL"]
```
Then, confirm that no diagnostics appear when you add code to an
`__init__.py` file (besides syntax errors).
The import sorting fix can be verified by failing to reproduce the
original issue - an `I001` diagnostic should not appear in
`other_module.py`.
## Summary
This builds off of the work in
https://github.com/astral-sh/ruff/pull/10652 to implement a command
executor, backwards compatible with the commands from the previous LSP
(`ruff.applyAutofix`, `ruff.applyFormat` and
`ruff.applyOrganizeImports`).
This involved a lot of refactoring and tweaks to the code action
resolution code - the most notable change is that workspace edits are
specified in a slightly different way, using the more general `changes`
field instead of the `document_changes` field (which isn't supported on
all LSP clients). Additionally, the API for synchronous request handlers
has been updated to include access to the `Requester`, which we use to
send a `workspace/applyEdit` request to the client.
## Test Plan
7932e30f-d944-4e35-b828-1d81aa56c087
## Summary
`ruff server` now has source action `source.fixAll` as an available code
action.
This also fixes https://github.com/astral-sh/ruff/issues/10593 in the
process of revising the code for quick fix code actions.
## Test Plan
f4c07425-e68a-445f-a4ed-949c9197a6be
## Summary
Fixes#10589.
Code that violates `F401` or `F841` (in other words, unused variables or
imports) should now appear greyed out or 'unused' in an editor.
## Test Plan
Put the following test code in a new file within the extension
development host window:
```python
import math
def func():
if False:
unused = "<- this should be greyed out"
```
The following test code should have greyed out/unused import and
variable names, like so:
<img width="294" alt="Screenshot 2024-03-28 at 4 23 18 AM"
src="e84a6e7a-49e2-4fed-9624-f8f9559e0837">
## Summary
Fixes#10588.
Most diagnostics from `ruff server` now appear as a much less alarming
warning instead of an error. Three diagnostics still appear as errors:
`F821` (`undefined name <name>`), `E902` (`IOError`) and `E999`
(`SyntaxError`).
## Test Plan
With an extension using the path to a locally-built executable, open a
file with multiple highlighted problems. Toggle the `Experimental
Server` setting on and off. The highlights should stay as warnings.
Then, modify the file to have a syntactically incorrect element. The
start of the invalid syntax should now have a red highlight.
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## Summary
This PR introduces the `ruff_server` crate and a new `ruff server`
command. `ruff_server` is a re-implementation of
[`ruff-lsp`](https://github.com/astral-sh/ruff-lsp), written entirely in
Rust. It brings significant performance improvements, much tighter
integration with Ruff, a foundation for supporting entirely new language
server features, and more!
This PR is an early version of `ruff_lsp` that we're calling the
**pre-release** version. Anyone is more than welcome to use it and
submit bug reports for any issues they encounter - we'll have some
documentation on how to set it up with a few common editors, and we'll
also provide a pre-release VSCode extension for those interested.
This pre-release version supports:
- **Diagnostics for `.py` files**
- **Quick fixes**
- **Full-file formatting**
- **Range formatting**
- **Multiple workspace folders**
- **Automatic linter/formatter configuration** - taken from any
`pyproject.toml` files in the workspace.
Many thanks to @MichaReiser for his [proof-of-concept
work](https://github.com/astral-sh/ruff/pull/7262), which was important
groundwork for making this PR possible.
## Architectural Decisions
I've made an executive choice to go with `lsp-server` as a base
framework for the LSP, in favor of `tower-lsp`. There were several
reasons for this:
1. I would like to avoid `async` in our implementation. LSPs are mostly
computationally bound rather than I/O bound, and `async` adds a lot of
complexity to the API, while also making harder to reason about
execution order. This leads into the second reason, which is...
2. Any handlers that mutate state should be blocking and run in the
event loop, and the state should be lock-free. This is the approach that
`rust-analyzer` uses (also with the `lsp-server`/`lsp-types` crates as a
framework), and it gives us assurances about data mutation and execution
order. `tower-lsp` doesn't support this, which has caused some
[issues](https://github.com/ebkalderon/tower-lsp/issues/284) around data
races and out-of-order handler execution.
3. In general, I think it makes sense to have tight control over
scheduling and the specifics of our implementation, in exchange for a
slightly higher up-front cost of writing it ourselves. We'll be able to
fine-tune it to our needs and support future LSP features without
depending on an upstream maintainer.
## Test Plan
The pre-release of `ruff_server` will have snapshot tests for common
document editing scenarios. An expanded test suite is on the roadmap for
future version of `ruff_server`.
