## Summary
This PR is a follow-up from https://github.com/astral-sh/ruff/pull/19551
and adds a new `ty.experimental.rename` setting to conditionally
register for the rename capability. The complementary PR in ty VS Code
extension is https://github.com/astral-sh/ty-vscode/pull/111.
This is done using dynamic registration after the settings have been
resolved. The experimental group is part of the global settings because
they're applied for all workspaces that are managed by the client.
## Test Plan
Add E2E tests.
In VS Code, with the following setting:
```json
{
"ty.experimental.rename": "true",
"python.languageServer": "None"
}
```
I get the relevant log entry:
```
2025-08-07 16:05:40.598709000 DEBUG client_response{id=3 method="client/registerCapability"}: Registered rename capability
```
And, I'm able to rename a symbol. Once I set it to `false`, then I can
see this log entry:
```
2025-08-07 16:08:39.027876000 DEBUG Rename capability is disabled in the client settings
```
And, I don't see the "Rename Symbol" open in the VS Code dropdown.
https://github.com/user-attachments/assets/501659df-ba96-4252-bf51-6f22acb4920b
## Summary
This PR updates the client settings handling to recognize unknown
options provided by the user and show a warning popup along with a
warning log message.
## Test Plan
Add E2E tests.
## Summary
This PR implements support for providing LSP client settings.
The complementary PR in the ty VS Code extension:
astral-sh/ty-vscode#106.
Notes for the previous iteration of this PR is in
https://github.com/astral-sh/ruff/pull/19614#issuecomment-3136477864
(click on "Details").
Specifically, this PR splits the client settings into 3 distinct groups.
Keep in mind that these groups are not visible to the user, they're
merely an implementation detail. The groups are:
1. `GlobalOptions` - these are the options that are global to the
language server and will be the same for all the workspaces that are
handled by the server
2. `WorkspaceOptions` - these are the options that are specific to a
workspace and will be applied only when running any logic for that
workspace
3. `InitializationOptions` - these are the options that can be specified
during initialization
The initialization options are a superset that contains both the global
and workspace options flattened into a 1-dimensional structure. This
means that the user can specify any and all fields present in
`GlobalOptions` and `WorkspaceOptions` in the initialization options in
addition to the fields that are _specific_ to initialization options.
From the current set of available settings, following are only available
during initialization because they are required at that time, are static
during the runtime of the server and changing their values require a
restart to take effect:
- `logLevel`
- `logFile`
And, following are available under `GlobalOptions`:
- `diagnosticMode`
And, following under `WorkspaceOptions`:
- `disableLanguageServices`
- `pythonExtension` (Python environment information that is populated by
the ty VS Code extension)
### `workspace/configuration`
This request allows server to ask the client for configuration to a
specific workspace. But, this is only supported by the client that has
the `workspace.configuration` client capability set to `true`. What to
do for clients that don't support pulling configurations?
In that case, the settings needs to be provided in the initialization
options and updating the values of those settings can only be done by
restarting the server. With the way this is implemented, this means that
if the client does not support pulling workspace configuration then
there's no way to specify settings specific to a workspace. Earlier,
this would've been possible by providing an array of client options with
an additional field which specifies which workspace the options belong
to but that adds complexity and clients that actually do not support
`workspace/configuration` would usually not support multiple workspaces
either.
Now, for the clients that do support this, the server will initiate the
request to get the configuration for all the workspaces at the start of
the server. Once the server receives these options, it will resolve them
for each workspace as follows:
1. Combine the client options sent during initialization with the
options specific to the workspace creating the final client options
that's specific to this workspace
2. Create a global options by combining the global options from (1) for
all workspaces which in turn will also combine the global options sent
during initialization
The global options are resolved into the global settings and are
available on the `Session` which is initialized with the default global
settings. The workspace options are resolved into the workspace settings
and are available on the respective `Workspace`.
The `SessionSnapshot` contains the global settings while the document
snapshot contains the workspace settings. We could add the global
settings to the document snapshot but that's currently not needed.
### Document diagnostic dynamic registration
Currently, the document diagnostic server capability is created based on
the `diagnosticMode` sent during initialization. But, that wouldn't
provide us with the complete picture. This means the server needs to
defer registering the document diagnostic capability at a later point
once the settings have been resolved.
This is done using dynamic registration for clients that support it. For
clients that do not support dynamic registration for document diagnostic
capability, the server advertises itself as always supporting workspace
diagnostics and work done progress token.
This dynamic registration now allows us to change the server capability
for workspace diagnostics based on the resolved `diagnosticMode` value.
In the future, once `workspace/didChangeConfiguration` is supported, we
can avoid the server restart when users have changed any client
settings.
## Test Plan
Add integration tests and recorded videos on the user experience in
various editors:
### VS Code
For VS Code users, the settings experience is unchanged because the
extension defines it's own interface on how the user can specify the
server setting. This means everything is under the `ty.*` namespace as
usual.
https://github.com/user-attachments/assets/c2e5ba5c-7617-406e-a09d-e397ce9c3b93
### Zed
For Zed, the settings experience has changed. Users can specify settings
during initialization:
```json
{
"lsp": {
"ty": {
"initialization_options": {
"logLevel": "debug",
"logFile": "~/.cache/ty.log",
"diagnosticMode": "workspace",
"disableLanguageServices": true
}
},
}
}
```
Or, can specify the options under the `settings` key:
```json
{
"lsp": {
"ty": {
"settings": {
"ty": {
"diagnosticMode": "openFilesOnly",
"disableLanguageServices": true
}
},
"initialization_options": {
"logLevel": "debug",
"logFile": "~/.cache/ty.log"
}
},
}
}
```
The `logLevel` and `logFile` setting still needs to go under the
initialization options because they're required by the server during
initialization.
We can remove the nesting of the settings under the "ty" namespace by
updating the return type of
db9ea0cdfd/src/tychecker.rs (L45-L49)
to be wrapped inside `ty` directly so that users can avoid doing the
double nesting.
There's one issue here which is that if the `diagnosticMode` is
specified in both the initialization option and settings key, then the
resolution is a bit different - if either of them is set to be
`workspace`, then it wins which means that in the following
configuration, the diagnostic mode is `workspace`:
```json
{
"lsp": {
"ty": {
"settings": {
"ty": {
"diagnosticMode": "openFilesOnly"
}
},
"initialization_options": {
"diagnosticMode": "workspace"
}
},
}
}
```
This behavior is mainly a result of combining global options from
various workspace configuration results. Users should not be able to
provide global options in multiple workspaces but that restriction
cannot be done on the server side. The ty VS Code extension restricts
these global settings to only be set in the user settings and not in
workspace settings but we do not control extensions in other editors.
https://github.com/user-attachments/assets/8e2d6c09-18e6-49e5-ab78-6cf942fe1255
### Neovim
Same as in Zed.
### Other
Other editors that do not support `workspace/configuration`, the users
would need to provide the server settings during initialization.
This PR adds support for the "selection range" language server feature.
This feature was recently requested by a ty user in [this feature
request](https://github.com/astral-sh/ty/issues/882).
This feature allows a client to implement "smart selection expansion"
based on the structure of the parse tree. For example, if you type
"shift-ctrl-right-arrow" in VS Code, the current selection will be
expanded to include the parent AST node. Conversely,
"shift-ctrl-left-arrow" shrinks the selection.
We will probably need to tune the granularity of selection expansion
based on user feedback. The initial implementation includes most AST
nodes, but users may find this to be too fine-grained. We have the
option of skipping some AST nodes that are not as meaningful when
editing code.
Co-authored-by: UnboundVariable <unbound@gmail.com>
This PR adds support for "document symbols" and "workspace symbols"
language server features. Most of the logic to implement these features
is shared.
The "document symbols" feature returns a list of all symbols within a
specified source file. Clients can specify whether they want a flat or
hierarchical list. Document symbols are typically presented by a client
in an "outline" form. Here's what this looks like in VS Code, for
example.
<img width="240" height="249" alt="image"
src="https://github.com/user-attachments/assets/82b11f4f-32ec-4165-ba01-d6496ad13bdf"
/>
The "workspace symbols" feature returns a list of all symbols across the
entire workspace that match some user-supplied query string. This allows
the user to quickly find and navigate to any symbol within their code.
<img width="450" height="134" alt="image"
src="https://github.com/user-attachments/assets/aac131e0-9464-4adf-8a6c-829da028c759"
/>
---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
This PR adds support for the "document highlights" language server
feature.
This feature allows a client to highlight all instances of a selected
name within a document. Without this feature, editors perform
highlighting based on a simple text match. This adds semantic knowledge.
The implementation of this feature largely overlaps that of the
recently-added "references" feature. This PR refactors the existing
"references.rs" module, separating out the functionality and tests that
are specific to the other language feature into a "goto_references.rs"
module. The "references.rs" module now contains the functionality that
is common to "goto references", "document highlights" and "rename"
(which is not yet implemented).
As part of this PR, I also created a new `ReferenceTarget` type which is
similar to the existing `NavigationTarget` type but better suited for
references. This idea was suggested by @MichaReiser in [this code review
feedback](https://github.com/astral-sh/ruff/pull/19475#discussion_r2224061006)
from a previous PR. Notably, this new type contains a field that
specifies the "kind" of the reference (read, write or other). This
"kind" is needed for the document highlights feature.
Before: all textual instances of `foo` are highlighted
<img width="156" height="126" alt="Screenshot 2025-07-23 at 12 51 09 PM"
src="https://github.com/user-attachments/assets/37ccdb2f-d48a-473d-89d5-8e89cb6c394e"
/>
After: only semantic matches are highlighted
<img width="164" height="157" alt="Screenshot 2025-07-23 at 12 52 05 PM"
src="https://github.com/user-attachments/assets/2efadadd-4691-4815-af04-b031e74c81b7"
/>
---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
## Summary
Closes: astral-sh/ty#88
This PR implements an initial version of a mock language server that can
be used to write e2e tests using the real server running in the
background.
The way it works is that you'd use the `TestServerBuilder` to help
construct the `TestServer` with the setup data. This could be the
workspace folders, populating the file and it's content in the memory
file system, setting the right client capabilities to make the server
respond correctly, etc. This can be expanded as we write more test
cases.
There are still a few things to follow-up on:
- ~In the `Drop` implementation, we should assert that there are no
pending notification, request and responses from the server that the
test code hasn't handled yet~ Implemented in [`afd1f82`
(#19391)](afd1f82bde)
- Reduce the setup boilerplate in any way we can
- Improve the final assertion, currently I'm just snapshotting the final
output
## Test Plan
Written a few test cases.
This PR implements "go to definition" and "go to declaration"
functionality for name nodes only. Future PRs will add support for
attributes, module names in import statements, keyword argument names,
etc.
This PR:
* Registers a declaration and definition request handler for the
language server.
* Splits out the `goto_type_definition` into its own module. The `goto`
module contains functionality that is common to `goto_type_definition`,
`goto_declaration` and `goto_definition`.
* Roughs in a new module `stub_mapping` that is not yet implemented. It
will be responsible for mapping a definition in a stub file to its
corresponding definition(s) in an implementation (source) file.
* Adds a new IDE support function `definitions_for_name` that collects
all of the definitions associated with a name and resolves any imports
(recursively) to find the original definitions associated with that
name.
* Adds a new `VisibleAncestorsIter` stuct that iterates up the scope
hierarchy but skips scopes that are not visible to starting scope.
---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
## Summary
This PR removes the `ConnectionInitializer` and inlines the
`initialize_start` and `initialize_finish` calls.
The main benefit of this is that it will allow us to use
[`Connection::memory`](https://docs.rs/lsp-server/latest/lsp_server/struct.Connection.html#method.memory)
in the mock server. That method returns two `Connection` where one of
them will represent the client side connection and the other will be
sent to the `Server::new` call to be used by the server. This way the
mock client can send notifications and requests to mimic the editor.
## Test Plan
I tested out the initialization process and checked that the initialized
result contains the server capabilities and server info.
This PR includes:
* Implemented core signature help logic
* Added new docstring method on Definition that returns a docstring for
function and class definitions
* Modified the display code for Signature that allows a signature string
to be broken into text ranges that correspond to each parameter in the
signature
* Augmented Signature struct so it can track the Definition for a
signature when available; this allows us to find the docstring
associated with the signature
* Added utility functions for parsing parameter documentation from three
popular docstring formats (Google, NumPy and reST)
* Implemented tests for all of the above
"Signature help" is displayed by an editor when you are typing a
function call expression. It is typically triggered when you type an
open parenthesis. The language server provides information about the
target function's signature (or multiple signatures), documentation, and
parameters.
Here is how this appears:

---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
This PR implements a basic semantic token provider for ty's language
server. This allows for more accurate semantic highlighting / coloring
within editors that support this LSP functionality.
Here are screen shots that show how code appears in VS Code using the
"rainbow" theme both before and after this change.


The token types and modifier tags in this implementation largely mirror
those used in Microsoft's default language server for Python.
The implementation supports two LSP interfaces. The first provides
semantic tokens for an entire document, and the second returns semantic
tokens for a requested range within a document.
The PR includes unit tests. It also includes comments that document
known limitations and areas for future improvements.
---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
## Summary
This PR adds initial support for workspace diagnostics in the ty server.
Reference spec:
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_diagnostic
This is currently implemented via the **pull diagnostics method** which
was added in the current version (3.17) and the server advertises it via
the `diagnosticProvider.workspaceDiagnostics` server capability.
**Note:** This might be a bit confusing but a workspace diagnostics is
not for a single workspace but for all the workspaces that the server
handles. These are the ones that the server received during
initialization. Currently, the ty server doesn't support multiple
workspaces so this capability is also limited to provide diagnostics
only for a single workspace (the first one if the client provided
multiple).
A new `ty.diagnosticMode` server setting is added which can be either
`workspace` (for workspace diagnostics) or `openFilesOnly` (for checking
only open files) (default). This is same as
`python.analysis.diagnosticMode` that Pyright / Pylance utilizes. In the
future, we could use the value under `python.*` namespace as fallback to
improve the experience on user side to avoid setting the value multiple
times.
Part of: astral-sh/ty#81
## Test Plan
This capability was introduced in the current LSP version (~3 years) and
the way it's implemented by various clients are a bit different. I've
provided notes on what I've noticed and what would need to be done on
our side to further improve the experience.
### VS Code
VS Code sends the `workspace/diagnostic` requests every ~2 second:
```
[Trace - 12:12:32 PM] Sending request 'workspace/diagnostic - (403)'.
[Trace - 12:12:32 PM] Received response 'workspace/diagnostic - (403)' in 2ms.
[Trace - 12:12:34 PM] Sending request 'workspace/diagnostic - (404)'.
[Trace - 12:12:34 PM] Received response 'workspace/diagnostic - (404)' in 2ms.
[Trace - 12:12:36 PM] Sending request 'workspace/diagnostic - (405)'.
[Trace - 12:12:36 PM] Received response 'workspace/diagnostic - (405)' in 2ms.
[Trace - 12:12:38 PM] Sending request 'workspace/diagnostic - (406)'.
[Trace - 12:12:38 PM] Received response 'workspace/diagnostic - (406)' in 3ms.
[Trace - 12:12:40 PM] Sending request 'workspace/diagnostic - (407)'.
[Trace - 12:12:40 PM] Received response 'workspace/diagnostic - (407)' in 2ms.
...
```
I couldn't really find any resource that explains this behavior. But,
this does mean that we'd need to implement the caching layer via the
previous result ids sooner. This will allow the server to avoid sending
all the diagnostics on every request and instead just send a response
stating that the diagnostics hasn't changed yet. This could possibly be
achieved by using the salsa ID.
If we switch from workspace diagnostics to open-files diagnostics, the
server would send the diagnostics only via the `textDocument/diagnostic`
endpoint. Here, when a document containing the diagnostic is closed, the
server would send a publish diagnostics notification with an empty list
of diagnostics to clear the diagnostics from that document. The issue is
the VS Code doesn't seem to be clearing the diagnostics in this case
even though it receives the notification. (I'm going to open an issue on
VS Code side for this today.)
https://github.com/user-attachments/assets/b0c0833d-386c-49f5-8a15-0ac9133e15ed
### Zed
Zed's implementation works by refreshing the workspace diagnostics
whenever the content of the documents are changed. This seems like a
very reasonable behavior and I was a bit surprised that VS Code didn't
use this heuristic.
https://github.com/user-attachments/assets/71c7b546-7970-434a-9ba0-4fa620647f6c
### Neovim
Neovim only recently added support for workspace diagnostics
(https://github.com/neovim/neovim/pull/34262, merged ~3 weeks ago) so
it's only available on nightly versions.
The initial support is limited and requires fetching the workspace
diagnostics manually as demonstrated in the video. It doesn't support
refreshing the workspace diagnostics either, so that would need to be
done manually as well. I'm assuming that these are just a temporary
limitation and will be implemented before the stable release.
https://github.com/user-attachments/assets/25b4a0e5-9833-4877-88ad-279904fffaf9
## Summary
This PR makes the necessary changes to the server that it can request
configurations from the client using the `configuration` request.
This PR doesn't make use of the request yet. It only sets up the
foundation (mainly the coordination between client and server)
so that future PRs could pull specific settings.
I plan to use this for pulling the Python environment from the Python
extension.
Deno does something very similar to this.
## Test Plan
Tested that diagnostics are still shown.
## Summary
PR adding support for it in the VS Code extension:
https://github.com/astral-sh/ty-vscode/pull/36
This PR adds support for `python.ty.disableLanguageServices` to the ty
language server by accepting this as server setting.
This has the same issue as https://github.com/astral-sh/ty/issues/282 in
that it only works when configured globally. Fixing that requires
support for multiple workspaces in the server itself.
I also went ahead and did a similar refactor as the Ruff server to use
"Options" and "Settings" to keep the code consistent although the
combine functionality doesn't exists yet because workspace settings
isn't supported in the ty server.
## Test Plan
Refer to https://github.com/astral-sh/ty-vscode/pull/36 for the test
demo.
Specifically, this PR reverts "Make completions an opt-in LSP feature
(#17921)",
corresponding to commit 51e2effd2d.
In practice, this means you don't need to opt into completions working
by enabling experimental features. i.e., I was able to remove this from
my LSP configuration:
```
"experimental": {
"completions": {
"enable": true
}
},
```
There's still a lot of work left to do to make completions awesome, but
I think it's in a state where it would be useful to get real user
feedback. It's also meaningfully using ty to provide completions that
use type information.
Ref astral-sh/ty#86
## Summary
This PR updates the language server to avoid panicking when there are
multiple workspace folders passed during initialization. The server
currently picks up the first workspace folder and provides a warning and
a log message.
## Test Plan
<img width="1724" alt="Screenshot 2025-05-17 at 11 43 09"
src="https://github.com/user-attachments/assets/1a7ddbc3-198d-4191-a28f-9b69321e8f99"
/>
## Summary
We now expect the client to send initialization options to opt-in to
experimental (but LSP-standardized) features, like completion support.
Specifically, the client should set `"experimental.completions.enable":
true`.
Closes https://github.com/astral-sh/ty/issues/74.