From a3a076d79f46bc52c6fc4e1ddbda90783568a07b Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrew@wheream.io>
Date: Wed, 3 Jul 2019 09:33:03 -0700
Subject: [PATCH] Did you forget to use await? for call and construct
 signatures

---
 src/compiler/checker.ts                       |  8 ++--
 src/compiler/diagnosticMessages.json          | 40 +++++++++++--------
 .../operationsAvailableOnPromisedType.ts      |  1 +
 3 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 63fa0f7e889..1a99c2642fd 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -22342,6 +22342,8 @@ namespace ts {
         function invocationErrorDetails(apparentType: Type, kind: SignatureKind): DiagnosticMessageChain {
             let errorInfo: DiagnosticMessageChain | undefined;
             const isCall = kind === SignatureKind.Call;
+            const awaitedType = getAwaitedType(apparentType);
+            const mightWorkWithAwait = awaitedType && getSignaturesOfType(awaitedType, kind).length > 0;
             if (apparentType.flags & TypeFlags.Union) {
                 const types = (apparentType as UnionType).types;
                 let hasSignatures = false;
@@ -22408,9 +22410,9 @@ namespace ts {
             }
             return chainDiagnosticMessages(
                 errorInfo,
-                isCall ?
-                    Diagnostics.This_expression_is_not_callable :
-                    Diagnostics.This_expression_is_not_constructable
+                mightWorkWithAwait
+                    ? isCall ? Diagnostics.This_expression_is_not_callable_Did_you_forget_to_use_await : Diagnostics.This_expression_is_not_constructable_Did_you_forget_to_use_await
+                    : isCall ? Diagnostics.This_expression_is_not_callable : Diagnostics.This_expression_is_not_constructable
             );
         }
         function invocationError(errorTarget: Node, apparentType: Type, kind: SignatureKind, relatedInformation?: DiagnosticRelatedInformation) {
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index a7b62838249..e3774296e0d 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -2705,50 +2705,58 @@
         "category": "Error",
         "code": 2775
     },
+    "This expression is not callable. Did you forget to use 'await'?": {
+        "category": "Error",
+        "code": 2776
+    },
+    "This expression is not constructable. Did you forget to use 'await'?": {
+        "category": "Error",
+        "code": 2777
+    },
     "The right-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type. Did you forget to use 'await'?": {
-        "category": "Error",
-        "code": 2777
-    },
-    "Type '{0}' must have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
-        "category": "Error",
-        "code": 2777
-    },
-    "Type '{0}' must have a '[Symbol.asyncIterator]()' method that returns an async iterator. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2778
     },
-    "Type '{0}' is not an array type. Did you forget to use 'await'?": {
+    "Type '{0}' must have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2779
     },
-    "Type '{0}' is not an array type or a string type. Did you forget to use 'await'?": {
+    "Type '{0}' must have a '[Symbol.asyncIterator]()' method that returns an async iterator. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2780
     },
-    "Type '{0}' is not an array type or does not have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
+    "Type '{0}' is not an array type. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2781
     },
-    "Type '{0}' is not an array type or a string type or does not have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
+    "Type '{0}' is not an array type or a string type. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2782
     },
-    "Argument of type '{0}' is not assignable to parameter of type '{1}'. Did you forget to use 'await'?": {
+    "Type '{0}' is not an array type or does not have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2783
     },
-    "Type '{0}' has no call signatures. Did you forget to use 'await'?": {
+    "Type '{0}' is not an array type or a string type or does not have a '[Symbol.iterator]()' method that returns an iterator. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2784
     },
-    "Type '{0}' has no construct signatures. Did you forget to use 'await'?": {
+    "Argument of type '{0}' is not assignable to parameter of type '{1}'. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2785
     },
-    "This condition will always return '{0}' since the types '{1}' and '{2}' have no overlap. Did you forget to use 'await'?": {
+    "Type '{0}' has no call signatures. Did you forget to use 'await'?": {
         "category": "Error",
         "code": 2786
     },
+    "Type '{0}' has no construct signatures. Did you forget to use 'await'?": {
+        "category": "Error",
+        "code": 2787
+    },
+    "This condition will always return '{0}' since the types '{1}' and '{2}' have no overlap. Did you forget to use 'await'?": {
+        "category": "Error",
+        "code": 2788
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
diff --git a/tests/cases/compiler/operationsAvailableOnPromisedType.ts b/tests/cases/compiler/operationsAvailableOnPromisedType.ts
index 76e2cea6dd8..f6e339eab7f 100644
--- a/tests/cases/compiler/operationsAvailableOnPromisedType.ts
+++ b/tests/cases/compiler/operationsAvailableOnPromisedType.ts
@@ -24,4 +24,5 @@ async function fn(
     e();
     f();
     new g();
+    b();
 }