feat(language_server): support textDocument/diagnostic

Author: Sysix

crates/oxc_language_server/README.md

@@ -14,16 +14,33 @@ This crate provides an [LSP](https://microsoft.github.io/language-server-protoco
   - `quickfix`
   - `source.fixAll.oxc`, behaves the same as `quickfix` only used when the `CodeActionContext#only` contains
     `source.fixAll.oxc`.
+- [Diagnostic Provider](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_pullDiagnostics)
+  - Only when [Diagnostics Refresh](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#diagnostic_refresh) is supported by your client
 
 ## Workspace Options
 
 These options can be passed with [initialize](#initialize), [workspace/didChangeConfiguration](#workspace/didChangeConfiguration) and [workspace/configuration](#workspace/configuration).
 
-| Option Key   | Value(s)               | Default    | Description                                                                                          |
-| ------------ | ---------------------- | ---------- | ---------------------------------------------------------------------------------------------------- |
-| `run`        | `"onSave" \| "onType"` | `"onType"` | Should the server lint the files when the user is typing or saving                                   |
-| `configPath` | `<string>` \| `null`   | `null`     | Path to a oxlint configuration file, passing a string will disable nested configuration              |
-| `flags`      | `Map<string, string>`  | `<empty>`  | Special oxc language server flags, currently only one flag key is supported: `disable_nested_config` |
+| Option Key   | Value(s)              | Default   | Description                                                                                          |
+| ------------ | --------------------- | --------- | ---------------------------------------------------------------------------------------------------- |
+| `configPath` | `<string>` \| `null`  | `null`    | Path to a oxlint configuration file, passing a string will disable nested configuration              |
+| `flags`      | `Map<string, string>` | `<empty>` | Special oxc language server flags, currently only one flag key is supported: `disable_nested_config` |
+
+### Flags
+
+- `key: disable_nested_config`: Disabled nested configuration and searches only for `configPath`
+- `key: fix_kind`: default: `"safe_fix"`, possible values `"safe_fix" | "safe_fix_or_suggestion" | "dangerous_fix" | "dangerous_fix_or_suggestion" | "none" | "all"`
+
+### Workspace Options without Diagnostic Provider
+
+| Option Key | Value(s)               | Default    | Description                                                        |
+| ---------- | ---------------------- | ---------- | ------------------------------------------------------------------ |
+| `run`      | `"onSave" \| "onType"` | `"onType"` | Should the server lint the files when the user is typing or saving |
+
+## Diagnostics Modes
+
+Depending on the client, the server will push diagnostics, or will wait for a pull request from the client.
+The server will prefer pull diagnostics when the client supports it and able to support [textDocument/diagnostic/refresh](#textdocumentdiagnosticrefresh).
 
 ## Supported LSP Specifications from Server
 
@@ -45,11 +62,6 @@ The client can pass the workspace options like following:
 }
 ```
 
-#### Flags
-
-- `key: disable_nested_config`: Disabled nested configuration and searches only for `configPath`
-- `key: fix_kind`: default: `"safe_fix"`, possible values `"safe_fix" | "safe_fix_or_suggestion" | "dangerous_fix" | "dangerous_fix_or_suggestion" | "none" | "all"`
-
 ### [initialized](https://microsoft.github.io/language-server-protocol/specification#initialized)
 
 When the client did not pass the workspace configuration in [initialize](#initialize), the server will request the configuration for every workspace with [workspace/configuration](#workspaceconfiguration).
@@ -121,17 +133,17 @@ When the configuration `run` is set to `onType`, the server will validate the fi
 
 It will remove the reference internal.
 
-#### [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction)
+#### [textDocument/diagnostics](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_diagnostic)
 
-Returns a list of [CodeAction](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_codeAction)
+ToDo:
 
-## Expected LSP Specification from Client
+#### [textDocument/diagnostic/refresh](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#diagnostic_refresh)
 
-### TextDocument
+ToDo:
 
-#### [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics)
+#### [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction)
 
-Returns a [PublishDiagnostic object](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#publishDiagnosticsParams)
+Returns a list of [CodeAction](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_codeAction)
 
 ## Optional LSP Specifications from Client
 
@@ -145,6 +157,12 @@ The server will send this request to watch for specific files. The method `works
 
 The server will send this request to stop watching for specific files. The `id` will match from [client/registerCapability](#clientregistercapability).
 
+### TextDocument
+
+#### [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics)
+
+ToDo:
+
 ### Workspace
 
 #### [workspace/configuration](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_configuration)

crates/oxc_language_server/src/capabilities.rs

@@ -1,23 +1,40 @@
 use tower_lsp_server::lsp_types::{
     ClientCapabilities, CodeActionKind, CodeActionOptions, CodeActionProviderCapability,
-    ExecuteCommandOptions, OneOf, SaveOptions, ServerCapabilities, TextDocumentSyncCapability,
-    TextDocumentSyncKind, TextDocumentSyncOptions, TextDocumentSyncSaveOptions,
-    WorkDoneProgressOptions, WorkspaceFoldersServerCapabilities, WorkspaceServerCapabilities,
+    DiagnosticOptions, DiagnosticServerCapabilities, ExecuteCommandOptions, OneOf, SaveOptions,
+    ServerCapabilities, TextDocumentSyncCapability, TextDocumentSyncKind, TextDocumentSyncOptions,
+    TextDocumentSyncSaveOptions, WorkDoneProgressOptions, WorkspaceFoldersServerCapabilities,
+    WorkspaceServerCapabilities,
 };
 
 use crate::{code_actions::CODE_ACTION_KIND_SOURCE_FIX_ALL_OXC, commands::FIX_ALL_COMMAND_ID};
 
-#[derive(Clone, Default)]
+/// Represents the capabilities of the client that the server can use to determine
+/// which features to enable or disable.
+#[derive(Clone, Default, Debug)]
 pub struct Capabilities {
     pub code_action_provider: bool,
     pub workspace_apply_edit: bool,
     pub workspace_execute_command: bool,
     pub workspace_configuration: bool,
+    /// Whether the client supports dynamic registration of file watchers.
     pub dynamic_watchers: bool,
+    /// Whether the client supports pull diagnostics.
+    pull_diagnostics: bool,
+    /// Whether the client supports the `workspace/diagnostic/refresh` request.
+    refresh_diagnostics: bool,
 }
 
-impl From<ClientCapabilities> for Capabilities {
-    fn from(value: ClientCapabilities) -> Self {
+impl Capabilities {
+    /// The server supports pull and push diagnostics.
+    /// Only use push diagnostics if the client does not support pull diagnostics,
+    /// or we can not the client to refresh diagnostics.
+    pub fn use_push_diagnostics(&self) -> bool {
+        !self.pull_diagnostics || !self.refresh_diagnostics
+    }
+}
+
+impl From<&ClientCapabilities> for Capabilities {
+    fn from(value: &ClientCapabilities) -> Self {
         // check if the client support some code action literal support
         let code_action_provider = value.text_document.as_ref().is_some_and(|capability| {
             capability.code_action.as_ref().is_some_and(|code_action| {
@@ -34,18 +51,33 @@ impl From<ClientCapabilities> for Capabilities {
             .workspace
             .as_ref()
             .is_some_and(|workspace| workspace.configuration.is_some_and(|config| config));
-        let dynamic_watchers = value.workspace.is_some_and(|workspace| {
-            workspace.did_change_watched_files.is_some_and(|watched_files| {
-                watched_files.dynamic_registration.is_some_and(|dynamic| dynamic)
+        let dynamic_watchers = value.workspace.as_ref().is_some_and(|workspace| {
+            workspace.did_change_watched_files.as_ref().is_some_and(|watched_files| {
+                watched_files.dynamic_registration.as_ref().is_some_and(|dynamic| *dynamic)
             })
         });
 
+        let pull_diagnostics = value
+            .text_document
+            .as_ref()
+            .is_some_and(|text_document| text_document.diagnostic.is_some());
+
+        // BUG: see https://github.com/tower-lsp-community/tower-lsp-server/issues/50
+        // let refresh_diagnostics = value.workspace.as_ref().is_some_and(|workspace| {
+        //     workspace
+        //         .diagnostic
+        //         .as_ref()
+        //         .is_some_and(|diagnostic| diagnostic.refresh_support.is_some_and(|refresh| refresh))
+        // });
+
         Self {
             code_action_provider,
             workspace_apply_edit,
             workspace_execute_command,
             workspace_configuration,
             dynamic_watchers,
+            pull_diagnostics,
+            refresh_diagnostics: true,
         }
     }
 }
@@ -92,6 +124,11 @@ impl From<Capabilities> for ServerCapabilities {
             } else {
                 None
             },
+            diagnostic_provider: if value.use_push_diagnostics() {
+                None
+            } else {
+                Some(DiagnosticServerCapabilities::Options(DiagnosticOptions::default()))
+            },
             ..ServerCapabilities::default()
         }
     }
@@ -108,6 +145,37 @@ mod test {
 
     use super::Capabilities;
 
+    #[test]
+    fn test_use_push_diagnostics() {
+        let capabilities = Capabilities {
+            pull_diagnostics: true,
+            refresh_diagnostics: true,
+            ..Default::default()
+        };
+        assert!(!capabilities.use_push_diagnostics());
+
+        let capabilities = Capabilities {
+            pull_diagnostics: false,
+            refresh_diagnostics: true,
+            ..Default::default()
+        };
+        assert!(capabilities.use_push_diagnostics());
+
+        let capabilities = Capabilities {
+            pull_diagnostics: true,
+            refresh_diagnostics: false,
+            ..Default::default()
+        };
+        assert!(capabilities.use_push_diagnostics());
+
+        let capabilities = Capabilities {
+            pull_diagnostics: false,
+            refresh_diagnostics: false,
+            ..Default::default()
+        };
+        assert!(capabilities.use_push_diagnostics());
+    }
+
     #[test]
     fn test_code_action_provider_vscode() {
         let client_capabilities = ClientCapabilities {
@@ -138,7 +206,7 @@ mod test {
             ..ClientCapabilities::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
 
         assert!(capabilities.code_action_provider);
     }
@@ -168,7 +236,7 @@ mod test {
             ..ClientCapabilities::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
 
         assert!(capabilities.code_action_provider);
     }
@@ -201,7 +269,7 @@ mod test {
             ..ClientCapabilities::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
 
         assert!(capabilities.code_action_provider);
     }
@@ -219,7 +287,7 @@ mod test {
             ..ClientCapabilities::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
 
         assert!(capabilities.workspace_execute_command);
     }
@@ -235,7 +303,7 @@ mod test {
             ..ClientCapabilities::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
 
         assert!(capabilities.workspace_apply_edit);
     }
@@ -253,7 +321,7 @@ mod test {
             ..Default::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
         assert!(capabilities.dynamic_watchers);
     }
 
@@ -270,7 +338,7 @@ mod test {
             ..Default::default()
         };
 
-        let capabilities = Capabilities::from(client_capabilities);
+        let capabilities = Capabilities::from(&client_capabilities);
         assert!(capabilities.dynamic_watchers);
     }
 }