Fixed an issue with property type display when contextual type is a union (#56318)

Author: Andarist

src/services/services.ts

@@ -3282,12 +3282,15 @@ export function getPropertySymbolsFromContextualType(node: ObjectLiteralElementW
         return symbol ? [symbol] : emptyArray;
     }
 
-    const discriminatedPropertySymbols = mapDefined(contextualType.types, t => (isObjectLiteralExpression(node.parent) || isJsxAttributes(node.parent)) && checker.isTypeInvalidDueToUnionDiscriminant(t, node.parent) ? undefined : t.getProperty(name));
+    const filteredTypes = isObjectLiteralExpression(node.parent) || isJsxAttributes(node.parent)
+        ? filter(contextualType.types, t => !checker.isTypeInvalidDueToUnionDiscriminant(t, node.parent))
+        : contextualType.types;
+    const discriminatedPropertySymbols = mapDefined(filteredTypes, t => t.getProperty(name));
     if (unionSymbolOk && (discriminatedPropertySymbols.length === 0 || discriminatedPropertySymbols.length === contextualType.types.length)) {
         const symbol = contextualType.getProperty(name);
         if (symbol) return [symbol];
     }
-    if (discriminatedPropertySymbols.length === 0) {
+    if (!filteredTypes.length && !discriminatedPropertySymbols.length) {
         // Bad discriminant -- do again without discriminating
         return mapDefined(contextualType.types, t => t.getProperty(name));
     }

tests/cases/fourslash/quickInfoFromContextualUnionType1.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts' />
+
+// @strict: true
+//// // based on https://github.com/microsoft/TypeScript/issues/55495
+//// type X =
+////   | {
+////       name: string;
+////       [key: string]: any;
+////     }
+////   | {
+////       name: "john";
+////       someProp: boolean;
+////     };
+////
+//// const obj = { name: "john", /*1*/someProp: "foo" } satisfies X;
+
+verify.quickInfoAt("1", "(property) someProp: string");