Extract a common HoverAdapter

src/common/lspLanguageFeatures.ts

@@ -390,3 +390,75 @@ function toCommand(c: lsTypes.Command | undefined): languages.Command | undefine
 }
 
 //#endregion
+
+//#region HoverAdapter
+
+export interface ILanguageWorkerWithHover {
+	doHover(uri: string, position: lsTypes.Position): Promise<lsTypes.Hover | null>;
+}
+
+export class HoverAdapter<T extends ILanguageWorkerWithHover> implements languages.HoverProvider {
+	constructor(private _worker: WorkerAccessor<T>) {}
+
+	provideHover(
+		model: editor.IReadOnlyModel,
+		position: Position,
+		token: CancellationToken
+	): Promise<languages.Hover | undefined> {
+		let resource = model.uri;
+
+		return this._worker(resource)
+			.then((worker) => {
+				return worker.doHover(resource.toString(), fromPosition(position));
+			})
+			.then((info) => {
+				if (!info) {
+					return;
+				}
+				return <languages.Hover>{
+					range: toRange(info.range),
+					contents: toMarkedStringArray(info.contents)
+				};
+			});
+	}
+}
+
+function isMarkupContent(thing: any): thing is lsTypes.MarkupContent {
+	return (
+		thing && typeof thing === 'object' && typeof (<lsTypes.MarkupContent>thing).kind === 'string'
+	);
+}
+
+function toMarkdownString(entry: lsTypes.MarkupContent | lsTypes.MarkedString): IMarkdownString {
+	if (typeof entry === 'string') {
+		return {
+			value: entry
+		};
+	}
+	if (isMarkupContent(entry)) {
+		if (entry.kind === 'plaintext') {
+			return {
+				value: entry.value.replace(/[\\`*_{}[\]()#+\-.!]/g, '\\$&')
+			};
+		}
+		return {
+			value: entry.value
+		};
+	}
+
+	return { value: '```' + entry.language + '\n' + entry.value + '\n```\n' };
+}
+
+function toMarkedStringArray(
+	contents: lsTypes.MarkupContent | lsTypes.MarkedString | lsTypes.MarkedString[]
+): IMarkdownString[] | undefined {
+	if (!contents) {
+		return void 0;
+	}
+	if (Array.isArray(contents)) {
+		return contents.map(toMarkdownString);
+	}
+	return [toMarkdownString(contents)];
+}
+
+//#endregion