Did you forget to use await? on arguments of function calls

src/compiler/checker.ts

@@ -21434,6 +21434,7 @@ namespace ts {
                     const checkArgType = checkMode & CheckMode.SkipContextSensitive ? getRegularTypeOfObjectLiteral(argType) : argType;
                     if (!checkTypeRelatedToAndOptionallyElaborate(checkArgType, paramType, relation, reportErrors ? arg : undefined, arg, headMessage, containingMessageChain, errorOutputContainer)) {
                         Debug.assert(!reportErrors || !!errorOutputContainer.errors, "parameter should have errors when reporting errors");
+                        maybeAddMissingAwaitInfo(arg, checkArgType, paramType);
                         return errorOutputContainer.errors || [];
                     }
                 }
@@ -21443,10 +21444,20 @@ namespace ts {
                 const errorNode = reportErrors ? argCount < args.length ? args[argCount] : node : undefined;
                 if (!checkTypeRelatedTo(spreadType, restType, relation, errorNode, headMessage, /*containingMessageChain*/ undefined, errorOutputContainer)) {
                     Debug.assert(!reportErrors || !!errorOutputContainer.errors, "rest parameter should have errors when reporting errors");
+                    maybeAddMissingAwaitInfo(errorNode, spreadType, restType);
                     return errorOutputContainer.errors || [];
                 }
             }
             return undefined;
+
+            function maybeAddMissingAwaitInfo(errorNode: Node | undefined, source: Type, target: Type) {
+                if (errorNode && reportErrors && errorOutputContainer.errors && errorOutputContainer.errors.length) {
+                    const awaitedTypeOfSource = getAwaitedTypeOfPromise(source);
+                    if (awaitedTypeOfSource && isTypeRelatedTo(awaitedTypeOfSource, target, relation)) {
+                        addRelatedInfo(errorOutputContainer.errors[0], createDiagnosticForNode(errorNode, Diagnostics.Did_you_forget_to_use_await));
+                    }
+                }
+            }
         }
 
         /**

src/compiler/diagnosticMessages.json

@@ -2757,6 +2757,10 @@
         "category": "Error",
         "code": 2788
     },
+    "Did you forget to use 'await'?": {
+        "category": "Error",
+        "code": 2789
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

tests/baselines/reference/operationsAvailableOnPromisedType.errors.txt

@@ -7,7 +7,7 @@ tests/cases/compiler/operationsAvailableOnPromisedType.ts(16,7): error TS2764: A
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(17,5): error TS2776: This condition will always return 'false' since the types 'number' and 'Promise<number>' have no overlap. Did you forget to use 'await'?
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(18,9): error TS2769: Type 'Promise<string[]>' is not an array type. Did you forget to use 'await'?
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(19,21): error TS2770: Type 'Promise<string[]>' is not an array type or a string type. Did you forget to use 'await'?
-tests/cases/compiler/operationsAvailableOnPromisedType.ts(20,9): error TS2554: Expected 7 arguments, but got 4.
+tests/cases/compiler/operationsAvailableOnPromisedType.ts(20,12): error TS2345: Argument of type 'Promise<number>' is not assignable to parameter of type 'number'.
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(21,11): error TS2570: Property 'prop' does not exist on type 'Promise<{ prop: string; }>'. Did you forget to use 'await'?
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(23,27): error TS2770: Type 'Promise<string[]>' is not an array type or a string type. Did you forget to use 'await'?
 tests/cases/compiler/operationsAvailableOnPromisedType.ts(24,5): error TS2774: This expression is not callable. Did you forget to use 'await'?
@@ -59,10 +59,10 @@ tests/cases/compiler/operationsAvailableOnPromisedType.ts(27,5): error TS2349: T
         for (const s of c) {
                         ~
 !!! error TS2770: Type 'Promise<string[]>' is not an array type or a string type. Did you forget to use 'await'?
-            fn(b, b, c, d);
-            ~~~~~~~~~~~~~~
-!!! error TS2554: Expected 7 arguments, but got 4.
-!!! related TS6210 tests/cases/compiler/operationsAvailableOnPromisedType.ts:6:5: An argument for 'e' was not provided.
+            fn(b, b, c, d, e, f, g);
+               ~
+!!! error TS2345: Argument of type 'Promise<number>' is not assignable to parameter of type 'number'.
+!!! related TS2777 tests/cases/compiler/operationsAvailableOnPromisedType.ts:20:12: Did you forget to use 'await'?
             d.prop;
               ~~~~
 !!! error TS2570: Property 'prop' does not exist on type 'Promise<{ prop: string; }>'. Did you forget to use 'await'?

tests/baselines/reference/operationsAvailableOnPromisedType.js

@@ -18,7 +18,7 @@ async function fn(
     a === b;
     [...c];
     for (const s of c) {
-        fn(b, b, c, d);
+        fn(b, b, c, d, e, f, g);
         d.prop;
     }
     for await (const s of c) {}
@@ -98,7 +98,7 @@ function fn(a, b, c, d, e, f, g) {
                     __spreadArrays(c);
                     for (_i = 0, c_2 = c; _i < c_2.length; _i++) {
                         s = c_2[_i];
-                        fn(b, b, c, d);
+                        fn(b, b, c, d, e, f, g);
                         d.prop;
                     }
                     _b.label = 1;

tests/baselines/reference/operationsAvailableOnPromisedType.symbols

@@ -65,12 +65,15 @@ async function fn(
 >s : Symbol(s, Decl(operationsAvailableOnPromisedType.ts, 18, 14))
 >c : Symbol(c, Decl(operationsAvailableOnPromisedType.ts, 2, 23))
 
-        fn(b, b, c, d);
+        fn(b, b, c, d, e, f, g);
 >fn : Symbol(fn, Decl(operationsAvailableOnPromisedType.ts, 0, 0))
 >b : Symbol(b, Decl(operationsAvailableOnPromisedType.ts, 1, 14))
 >b : Symbol(b, Decl(operationsAvailableOnPromisedType.ts, 1, 14))
 >c : Symbol(c, Decl(operationsAvailableOnPromisedType.ts, 2, 23))
 >d : Symbol(d, Decl(operationsAvailableOnPromisedType.ts, 3, 25))
+>e : Symbol(e, Decl(operationsAvailableOnPromisedType.ts, 4, 33))
+>f : Symbol(f, Decl(operationsAvailableOnPromisedType.ts, 5, 27))
+>g : Symbol(g, Decl(operationsAvailableOnPromisedType.ts, 6, 42))
 
         d.prop;
 >d : Symbol(d, Decl(operationsAvailableOnPromisedType.ts, 3, 25))

tests/baselines/reference/operationsAvailableOnPromisedType.types

@@ -68,13 +68,16 @@ async function fn(
 >s : any
 >c : Promise<string[]>
 
-        fn(b, b, c, d);
->fn(b, b, c, d) : Promise<void>
+        fn(b, b, c, d, e, f, g);
+>fn(b, b, c, d, e, f, g) : Promise<void>
 >fn : (a: number, b: Promise<number>, c: Promise<string[]>, d: Promise<{ prop: string; }>, e: Promise<() => void>, f: Promise<() => void> | (() => void), g: Promise<new () => any>) => Promise<void>
 >b : Promise<number>
 >b : Promise<number>
 >c : Promise<string[]>
 >d : Promise<{ prop: string; }>
+>e : Promise<() => void>
+>f : Promise<() => void> | (() => void)
+>g : Promise<new () => any>
 
         d.prop;
 >d.prop : any

tests/cases/compiler/operationsAvailableOnPromisedType.ts

@@ -17,7 +17,7 @@ async function fn(
     a === b;
     [...c];
     for (const s of c) {
-        fn(b, b, c, d);
+        fn(b, b, c, d, e, f, g);
         d.prop;
     }
     for await (const s of c) {}