fix #83400

src/vs/workbench/api/common/extHostLanguageFeatures.ts

@@ -635,6 +635,12 @@ class SuggestAdapter {
 		const doc = this._documents.getDocument(resource);
 		const pos = typeConvert.Position.to(position);
 
+		// The default insert/replace ranges. It's important to compute them
+		// before asynchronously asking the provider for its results. See
+		// https://github.com/microsoft/vscode/issues/83400#issuecomment-546851421
+		const replaceRange = doc.getWordRangeAtPosition(pos) || new Range(pos, pos);
+		const insertRange = replaceRange.with({ end: pos });
+
 		return asPromise(() => this._provider.provideCompletionItems(doc, pos, token, typeConvert.CompletionContext.to(context))).then(value => {
 
 			if (!value) {
@@ -655,10 +661,6 @@ class SuggestAdapter {
 			const disposables = new DisposableStore();
 			this._disposables.set(pid, disposables);
 
-			// the default text edit range
-			const replaceRange = doc.getWordRangeAtPosition(pos) || new Range(pos, pos);
-			const insertRange = replaceRange.with({ end: pos });
-
 			const result: extHostProtocol.ISuggestResultDto = {
 				x: pid,
 				b: [],