Higher order this parameter inference, like microsoft#31116

jablko · jablko · commit 5f1d1af7c807 · 2019-11-29T00:09:43.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -23726,7 +23726,7 @@ namespace ts {
             const thisType = getThisTypeOfSignature(signature);
             if (thisType) {
                 const thisArgumentNode = getThisArgumentOfCall(node);
-                const thisArgumentType = thisArgumentNode ? checkExpression(thisArgumentNode) : voidType;
+                const thisArgumentType = thisArgumentNode ? checkExpressionWithContextualType(thisArgumentNode, thisType, context, checkMode) : voidType;
                 inferTypes(context.inferences, thisArgumentType, thisType);
             }
 

Original file line number	Diff line number	Diff line change
`@@ -23726,7 +23726,7 @@ namespace ts {`
`23726`	`23726`	`const thisType = getThisTypeOfSignature(signature);`
`23727`	`23727`	`if (thisType) {`
`23728`	`23728`	`const thisArgumentNode = getThisArgumentOfCall(node);`
`23729`		`- const thisArgumentType = thisArgumentNode ? checkExpression(thisArgumentNode) : voidType;`
	`23729`	`+ const thisArgumentType = thisArgumentNode ? checkExpressionWithContextualType(thisArgumentNode, thisType, context, checkMode) : voidType;`
`23730`	`23730`	`inferTypes(context.inferences, thisArgumentType, thisType);`
`23731`	`23731`	`}`
`23732`	`23732`