[WIP] Promises to Async Await Code Fix

src/compiler/checker.ts

@@ -120,6 +120,7 @@ namespace ts {
                 return node ? getTypeFromTypeNode(node) : errorType;
             },
             getParameterType: getTypeAtPosition,
+            getPromisedTypeOfPromise,
             getReturnTypeOfSignature,
             getNullableType,
             getNonNullableType,

src/compiler/diagnosticMessages.json

@@ -4098,7 +4098,10 @@
         "category": "Suggestion",
         "code": 80005
     },
-
+    "This may be converted to an async function.": {
+        "category": "Suggestion",
+        "code": 80006
+    },
     "Add missing 'super()' call": {
         "category": "Message",
         "code": 90001
@@ -4446,5 +4449,13 @@
     "Convert named export to default export": {
         "category": "Message",
         "code": 95062
+    },
+    "Convert to async function":{
+        "category": "Message",
+         "code": 95063
+    },
+    "Convert all to async functions": {
+        "category": "Message",
+        "code": 95064
     }
-}
+}

src/compiler/types.ts

@@ -2885,6 +2885,8 @@ namespace ts {
         getBaseTypes(type: InterfaceType): BaseType[];
         getBaseTypeOfLiteralType(type: Type): Type;
         getWidenedType(type: Type): Type;
+        /* @internal */
+        getPromisedTypeOfPromise(promise: Type, errorNode?: Node): Type | undefined;
         getReturnTypeOfSignature(signature: Signature): Type;
         /**
          * Gets the type of a parameter at a given position in a signature.