Fix :| edge case

actions-languageservice/src/complete.test.ts

@@ -157,7 +157,7 @@ jobs:
     const result = await complete(...getPositionFromCursor(input));
 
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(17);
+    expect(result.length).toEqual(0);
   });
 
   it("custom value providers override defaults", async () => {

actions-languageservice/src/complete.ts

@@ -40,6 +40,15 @@ export async function complete(
   valueProviderConfig?: ValueProviderConfig,
   contextProviderConfig?: ContextProviderConfig
 ): Promise<CompletionItem[]> {
+  // Edge case: when completing a key like `foo:|`, do not calculate auto-completions
+  const charBeforePos = textDocument.getText({
+    start: {line: position.line, character: position.character - 1},
+    end: {line: position.line, character: position.character}
+  });
+  if (charBeforePos === ":") {
+    return [];
+  }
+
   // Fix the input to work around YAML parsing issues
   const [newDoc, newPos] = transform(textDocument, position);