## Summary
This PR introduces a structured `DiagnosticId` instead of using a plain
`&'static str`. It is the first of three in a stack that implements a
basic rules infrastructure for Red Knot.
`DiagnosticId` is an enum over all known diagnostic codes. A closed enum
reduces the risk of accidentally introducing two identical diagnostic
codes. It also opens the possibility of generating reference
documentation from the enum in the future (not part of this PR).
The enum isn't *fully closed* because it uses a `&'static str` for lint
names. This is because we want the flexibility to define lints in
different crates, and all names are only known in `red_knot_linter` or
above. Still, lower-level crates must already reference the lint names
to emit diagnostics. We could define all lint-names in `DiagnosticId`
but I decided against it because:
* We probably want to share the `DiagnosticId` type between Ruff and Red
Knot to avoid extra complexity in the diagnostic crate, and both tools
use different lint names.
* Lints require a lot of extra metadata beyond just the name. That's why
I think defining them close to their implementation is important.
In the long term, we may also want to support plugins, which would make
it impossible to know all lint names at compile time. The next PR in the
stack introduces extra syntax for defining lints.
A closed enum does have a few disadvantages:
* rustc can't help us detect unused diagnostic codes because the enum is
public
* Adding a new diagnostic in the workspace crate now requires changes to
at least two crates: It requires changing the workspace crate to add the
diagnostic and the `ruff_db` crate to define the diagnostic ID. I
consider this an acceptable trade. We may want to move `DiagnosticId` to
its own crate or into a shared `red_knot_diagnostic` crate.
## Preventing duplicate diagnostic identifiers
One goal of this PR is to make it harder to introduce ambiguous
diagnostic IDs, which is achieved by defining a closed enum. However,
the enum isn't fully "closed" because it doesn't explicitly list the IDs
for all lint rules. That leaves the possibility that a lint rule and a
diagnostic ID share the same name.
I made the names unambiguous in this PR by separating them into
different namespaces by using `lint/<rule>` for lint rule codes. I don't
mind the `lint` prefix in a *Ruff next* context, but it is a bit weird
for a standalone type checker. I'd like to not overfocus on this for now
because I see a few different options:
* We remove the `lint` prefix and add a unit test in a top-level crate
that iterates over all known lint rules and diagnostic IDs to ensure the
names are non-overlapping.
* We only render `[lint]` as the error code and add a note to the
diagnostic mentioning the lint rule. This is similar to clippy and has
the advantage that the header line remains short
(`lint/some-long-rule-name` is very long ;))
* Any other form of adjusting the diagnostic rendering to make the
distinction clear
I think we can defer this decision for now because the `DiagnosticId`
contains all the relevant information to change the rendering
accordingly.
## Why `Lint` and not `LintRule`
I see three kinds of diagnostics in Red Knot:
* Non-suppressable: Reveal type, IO errors, configuration errors, etc.
(any `DiagnosticId`)
* Lints: code-related diagnostics that are suppressable.
* Lint rules: The same as lints, but they can be enabled or disabled in
the configuration. The majority of lints in Red Knot and the Ruff
linter.
Our current implementation doesn't distinguish between lints and Lint
rules because we aren't aware of a suppressible code-related lint that
can't be configured in the configuration. The only lint that comes to my
mind is maybe `division-by-zero` if we're 99.99% sure that it is always
right. However, I want to keep the door open to making this distinction
in the future if it proves useful.
Another reason why I chose lint over lint rule (or just rule) is that I
want to leave room for a future lint rule and lint phase concept:
* lint is the *what*: a specific code smell, pattern, or violation
* the lint rule is the *how*: I could see a future `LintRule` trait in
`red_knot_python_linter` that provides the necessary hooks to run as
part of the linter. A lint rule produces diagnostics for exactly one
lint. A lint rule differs from all lints in `red_knot_python_semantic`
because they don't run as "rules" in the Ruff sense. Instead, they're a
side-product of type inference.
* the lint phase is a different form of *how*: A lint phase can produce
many different lints in a single pass. This is a somewhat common pattern
in Ruff where running one analysis collects the necessary information
for finding many different lints
* diagnostic is the *presentation*: Unlike a lint, the diagnostic isn't
the what, but how a specific lint gets presented. I expect that many
lints can use one generic `LintDiagnostic`, but a few lints might need
more flexibility and implement their custom diagnostic rendering (at
least custom `Diagnostic` implementation).
## Test Plan
`cargo test`
## Summary
...and remove periods from messages that don't span more than a single
sentence.
This is more consistent with how we present user-facing messages in uv
(which has a defined style guide).
## Summary
This PR simplifies the virtual file support in the red knot core,
specifically:
* Update `File::add_virtual_file` method to `File::virtual_file` which
will always create a new virtual file and override the existing entry in
the lookup table
* Add `VirtualFile` which is a wrapper around `File` and provides
methods to increment the file revision / close the virtual file
* Add a new `File::try_virtual_file` to lookup the `VirtualFile` from
`Files`
* Add `File::sync_virtual_path` which takes in the `SystemVirtualPath`,
looks up the `VirtualFile` for it and calls the `sync` method to
increment the file revision
* Removes the `virtual_path_metadata` method on `System` trait
## Test Plan
- [x] Make sure the existing red knot tests pass
- [x] Updated code works well with the LSP
## Summary
This PR adds support for `textDocument/didChange` notification.
There seems to be a bug (probably in Salsa) where it panics with:
```
2024-08-22 15:33:38.802 [info] panicked at /Users/dhruv/.cargo/git/checkouts/salsa-61760caba2b17ca5/f608ff8/src/tracked_struct.rs:377:9:
two concurrent writers to Id(4800), should not be possible
```
## Test Plan
https://github.com/user-attachments/assets/81055feb-ba8e-4acf-ad2f-94084a3efead
## Summary
This PR adds basic support for files outside of any workspace in the red
knot server.
This also limits the red knot server to only work in a single workspace.
The server will not start if there are multiple workspaces.
## Test Plan
https://github.com/user-attachments/assets/de601387-0ad5-433c-9d2c-7b6ae5137654
## Summary
This PR removes notebook sync support from server capabilities because
it isn't tested, it'll be added back once we actually add full support
for notebook.
## Summary
This PR adds very basic support for using the line / column information
from the diagnostic message. This makes it easier to validate
diagnostics in an editor as oppose to going through the diff one
diagnostic at a time and confirming it at the location.
## Summary
This PR adds support for VS Code specific cell metadata to consider when
collecting valid code cells.
For context, Ruff only runs on valid code cells. These are the code
cells that doesn't contain cell magics. Previously, Ruff only used the
notebook's metadata to determine whether it's a Python notebook. But, in
VS Code, a notebook's preferred language might be Python but it could
still contain code cells for other languages. This can be determined
with the `metadata.vscode.languageId` field.
### References:
* https://code.visualstudio.com/docs/languages/identifiers
* e6c009a3d4/extensions/ipynb/src/serializers.ts (L104-L107)
*
e6c009a3d4/extensions/ipynb/src/serializers.ts (L117-L122)
This brings us one step closer to fixing #12281.
## Test Plan
Add test cases for `is_valid_python_code_cell` and an integration test
case which showcase running it end to end. The test notebook contains a
JavaScript code cell and a Python code cell.
