Language Server: Implement textDocument/onTypeFormatting for ERB block closers

javascript/packages/language-server/src/capabilities.ts

@@ -20,6 +20,7 @@ export class Capabilities {
   readonly hasConfiguration: boolean
   readonly hasWorkspaceFolders: boolean
   readonly hasDiagnosticRelatedInformation: boolean
+  readonly hasApplyEdit: boolean
   readonly hasShowDocument: boolean
 
   constructor(params: InitializeParams) {
@@ -28,6 +29,7 @@ export class Capabilities {
 
     this.hasConfiguration = !!this.client.workspace?.configuration
     this.hasWorkspaceFolders = !!this.client.workspace?.workspaceFolders
+    this.hasApplyEdit = !!this.client.workspace?.applyEdit
     this.hasShowDocument = !!this.client.window?.showDocument
     this.hasDiagnosticRelatedInformation = !!this.client.textDocument?.publishDiagnostics?.relatedInformation
   }

javascript/packages/language-server/src/on_type_formatting.ts

@@ -0,0 +1,5 @@
+import type { DocumentOnTypeFormattingOptions } from "vscode-languageserver/node"
+
+export const ON_TYPE_FORMATTING_OPTIONS: DocumentOnTypeFormattingOptions = {
+  firstTriggerCharacter: ">",
+}

javascript/packages/language-server/src/server.ts

@@ -10,6 +10,7 @@ import {
   Connection,
   DocumentFormattingParams,
   DocumentRangeFormattingParams,
+  DocumentOnTypeFormattingParams,
   CodeActionParams,
   CodeActionKind,
   FoldingRangeParams,
@@ -32,6 +33,7 @@ import { Config } from "@herb-tools/config"
 import { isPartialPath } from "@herb-tools/analysis"
 import { isConfigDocument, isPathInside } from "./utils"
 import { serverVersion } from "./build_info"
+import { ON_TYPE_FORMATTING_OPTIONS } from "./on_type_formatting"
 
 import type { FileEvent } from "vscode-languageserver/node"
 import type { ExtractToPartialResult } from "@herb-tools/language-service"
@@ -73,6 +75,7 @@ export class Server {
           },
           documentFormattingProvider: true,
           documentRangeFormattingProvider: true,
+          documentOnTypeFormattingProvider: ON_TYPE_FORMATTING_OPTIONS,
           codeActionProvider: {
             codeActionKinds: [CodeActionKind.QuickFix, CodeActionKind.SourceFixAll, CodeActionKind.RefactorRewrite, CodeActionKind.RefactorExtract]
           },
@@ -199,6 +202,52 @@ export class Server {
       return this.session.projects.get(params.textDocument.uri)?.formattingProvider.formatRange(params) ?? []
     })
 
+    this.connection.onDocumentOnTypeFormatting(async (params: DocumentOnTypeFormattingParams) => {
+      const document = this.session.documents.get(params.textDocument.uri)
+
+      if (!document) return []
+
+      const formatting = this.session.onTypeFormattingProvider.getFormatting(
+        document,
+        params.position,
+        params.ch,
+        params.options,
+      )
+
+      if (
+        formatting.cursor === null ||
+        !this.session.capabilities.hasApplyEdit ||
+        !this.session.capabilities.hasShowDocument
+      ) {
+        return formatting.edits
+      }
+
+      const applyResult = await this.connection.workspace.applyEdit({
+        changes: { [document.uri]: formatting.edits },
+      })
+
+      if (!applyResult.applied) return formatting.edits
+
+      try {
+        const showResult = await this.connection.window.showDocument({
+          uri: document.uri,
+          takeFocus: true,
+          selection: {
+            start: formatting.cursor,
+            end: formatting.cursor,
+          },
+        })
+
+        if (!showResult.success) {
+          this.connection.console.warn("Failed to move the cursor after on-type formatting")
+        }
+      } catch (error) {
+        this.connection.console.error(`Failed to move the cursor after on-type formatting: ${error}`)
+      }
+
+      return []
+    })
+
     this.connection.onDocumentHighlight((params: DocumentHighlightParams) => {
       const document = this.session.documents.get(params.textDocument.uri)
 

javascript/packages/language-server/src/session.ts

@@ -9,7 +9,20 @@ import { Capabilities } from "./capabilities"
 import { WorkspaceFolders } from "./workspace_folders"
 import { Documents } from "./documents"
 import { DiagnosticsPublisher } from "./diagnostics_publisher"
-import { ParserService, FoldingRangeProvider, SelectionRangeProvider, DocumentHighlightProvider, InlayHintProvider, HoverProvider, RewriteCodeActionProvider, CommentProvider, DocumentSymbolProvider, ExtractCodeActionProvider, DefinitionProvider } from "@herb-tools/language-service"
+import {
+  CommentProvider,
+  DefinitionProvider,
+  DocumentHighlightProvider,
+  DocumentSymbolProvider,
+  ExtractCodeActionProvider,
+  FoldingRangeProvider,
+  HoverProvider,
+  InlayHintProvider,
+  OnTypeFormattingProvider,
+  ParserService,
+  RewriteCodeActionProvider,
+  SelectionRangeProvider,
+} from "@herb-tools/language-service"
 import { ConfigService } from "./config_service"
 import { SaveOrchestrator } from "./save_orchestrator"
 
@@ -42,6 +55,7 @@ export class Session {
   definitionProvider: DefinitionProvider
   commentProvider: CommentProvider
   documentSymbolProvider: DocumentSymbolProvider
+  onTypeFormattingProvider: OnTypeFormattingProvider
 
   constructor(connection: Connection, params: InitializeParams) {
     this.connection = connection
@@ -77,6 +91,7 @@ export class Session {
     this.rewriteCodeActionProvider = new RewriteCodeActionProvider(this.parserService, process.cwd())
     this.commentProvider = new CommentProvider(this.parserService)
     this.documentSymbolProvider = new DocumentSymbolProvider(this.parserService)
+    this.onTypeFormattingProvider = new OnTypeFormattingProvider(this.parserService)
 
     this.extractCodeActionProvider = new ExtractCodeActionProvider(this.parserService, this.capabilities, existsSync)
 

javascript/packages/language-server/test/capabilities.test.ts

@@ -18,6 +18,7 @@ describe("Capabilities", () => {
 
       expect(capabilities.hasConfiguration).toBe(false)
       expect(capabilities.hasWorkspaceFolders).toBe(false)
+      expect(capabilities.hasApplyEdit).toBe(false)
       expect(capabilities.hasShowDocument).toBe(false)
       expect(capabilities.hasDiagnosticRelatedInformation).toBe(false)
     })
@@ -26,14 +27,19 @@ describe("Capabilities", () => {
       const capabilities = new Capabilities({
         ...mockParams,
         capabilities: {
-          workspace: { configuration: true, workspaceFolders: true },
+          workspace: {
+            applyEdit: true,
+            configuration: true,
+            workspaceFolders: true,
+          },
           window: { showDocument: { support: true } },
           textDocument: { publishDiagnostics: { relatedInformation: true } }
         }
       })
 
       expect(capabilities.hasConfiguration).toBe(true)
       expect(capabilities.hasWorkspaceFolders).toBe(true)
+      expect(capabilities.hasApplyEdit).toBe(true)
       expect(capabilities.hasShowDocument).toBe(true)
       expect(capabilities.hasDiagnosticRelatedInformation).toBe(true)
     })