Add support for code folding

README.md

@@ -17,6 +17,7 @@ files:
 - Automatically load remote schema files (by enabling DiagnosticsOptions.enableSchemaRequest)
 - Links from JSON references.
 - Links and hover effects from YAML anchors.
+- Code folding.
 
 Schemas can also be provided by configuration. See
 [here](https://github.com/remcohaszing/monaco-yaml/blob/main/index.d.ts) for the API that the plugin

src/index.ts

@@ -10,6 +10,7 @@ import {
   createDefinitionProvider,
   createDocumentFormattingEditProvider,
   createDocumentSymbolProvider,
+  createFoldingRangeProvider,
   createHoverProvider,
   createLinkProvider,
   createMarkerDataProvider
@@ -76,6 +77,11 @@ export function configureMonacoYaml(monaco: MonacoEditor, options: MonacoYamlOpt
 
     monaco.languages.registerCodeActionProvider('yaml', createCodeActionProvider(worker.getWorker)),
 
+    monaco.languages.registerFoldingRangeProvider(
+      'yaml',
+      createFoldingRangeProvider(worker.getWorker)
+    ),
+
     monaco.languages.setLanguageConfiguration('yaml', {
       comments: {
         lineComment: '#'

src/languageFeatures.ts

@@ -1,11 +1,13 @@
 import { type languages } from 'monaco-editor/esm/vs/editor/editor.api.js'
 import {
+  fromFoldingRangeContext,
   fromMarkerData,
   fromPosition,
   fromRange,
   toCodeAction,
   toCompletionList,
   toDocumentSymbol,
+  toFoldingRange,
   toHover,
   toLink,
   toLocationLink,
@@ -168,3 +170,19 @@ export function createCodeActionProvider(getWorker: WorkerAccessor): languages.C
     }
   }
 }
+
+export function createFoldingRangeProvider(
+  getWorker: WorkerAccessor
+): languages.FoldingRangeProvider {
+  return {
+    async provideFoldingRanges(model) {
+      const resource = model.uri
+
+      const worker = await getWorker(resource)
+      const foldingRanges = await worker.getFoldingRanges(String(resource))
+      console.log(foldingRanges)
+
+      return foldingRanges?.map(toFoldingRange)
+    }
+  }
+}

src/yaml.worker.ts

@@ -7,6 +7,7 @@ import {
   type Diagnostic,
   type DocumentLink,
   type DocumentSymbol,
+  type FoldingRange,
   type Hover,
   type LocationLink,
   type Position,
@@ -45,6 +46,8 @@ export interface YAMLWorker {
   findLinks: (uri: string) => DocumentLink[] | undefined
 
   getCodeAction: (uri: string, range: Range, diagnostics: Diagnostic[]) => CodeAction[] | undefined
+
+  getFoldingRanges: (uri: string) => FoldingRange[] | null | undefined
 }
 
 const telemetry: Telemetry = {
@@ -116,6 +119,10 @@ initialize<YAMLWorker, MonacoYamlOptions>((ctx, { enableSchemaRequest, ...langua
         textDocument: document,
         context: { diagnostics }
       })
+    ),
+
+    getFoldingRanges: withDocument((document) =>
+      ls.getFoldingRanges(document, { lineFoldingOnly: true })
     )
   }
 })