Minor fixes

ahejlsberg · ahejlsberg · commit aff7886510a9 · 2021-01-14T14:58:02.000-10:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -13255,12 +13255,12 @@ namespace ts {
             return includes;
         }
 
-        function removeSubtypes(types: Type[]): boolean {
+        function removeSubtypes(types: Type[], hasObjectTypes: boolean): boolean {
             // We assume that redundant primitive types have already been removed from the types array and that there
             // are no any and unknown types in the array. Thus, the only possible supertypes for primitive types are empty
             // object types, and if none of those are present we can exclude primitive types from the subtype check.
-            const hasEmptyObject = some(types, t => !!(t.flags & TypeFlags.Object) && !isGenericMappedType(t) && isEmptyResolvedType(resolveStructuredTypeMembers(<ObjectType>t)));
-            let len = types.length;
+            const hasEmptyObject = hasObjectTypes && some(types, t => !!(t.flags & TypeFlags.Object) && !isGenericMappedType(t) && isEmptyResolvedType(resolveStructuredTypeMembers(<ObjectType>t)));
+            const len = types.length;
             let i = len;
             let count = 0;
             while (i > 0) {
@@ -13382,7 +13382,7 @@ namespace ts {
                     }
                 }
                 if (unionReduction & UnionReduction.Subtype) {
-                    if (!removeSubtypes(typeSet)) {
+                    if (!removeSubtypes(typeSet, !!(includes & TypeFlags.Object))) {
                         return errorType;
                     }
                 }

Original file line number	Diff line number	Diff line change
`@@ -13255,12 +13255,12 @@ namespace ts {`
`13255`	`13255`	`return includes;`
`13256`	`13256`	`}`
`13257`	`13257`
`13258`		`- function removeSubtypes(types: Type[]): boolean {`
	`13258`	`+ function removeSubtypes(types: Type[], hasObjectTypes: boolean): boolean {`
`13259`	`13259`	`// We assume that redundant primitive types have already been removed from the types array and that there`
`13260`	`13260`	`// are no any and unknown types in the array. Thus, the only possible supertypes for primitive types are empty`
`13261`	`13261`	`// object types, and if none of those are present we can exclude primitive types from the subtype check.`
`13262`		`- const hasEmptyObject = some(types, t => !!(t.flags & TypeFlags.Object) && !isGenericMappedType(t) && isEmptyResolvedType(resolveStructuredTypeMembers(<ObjectType>t)));`
`13263`		`- let len = types.length;`
	`13262`	`+ const hasEmptyObject = hasObjectTypes && some(types, t => !!(t.flags & TypeFlags.Object) && !isGenericMappedType(t) && isEmptyResolvedType(resolveStructuredTypeMembers(<ObjectType>t)));`
	`13263`	`+ const len = types.length;`
`13264`	`13264`	`let i = len;`
`13265`	`13265`	`let count = 0;`
`13266`	`13266`	`while (i > 0) {`
`@@ -13382,7 +13382,7 @@ namespace ts {`
`13382`	`13382`	`}`
`13383`	`13383`	`}`
`13384`	`13384`	`if (unionReduction & UnionReduction.Subtype) {`
`13385`		`- if (!removeSubtypes(typeSet)) {`
	`13385`	`+ if (!removeSubtypes(typeSet, !!(includes & TypeFlags.Object))) {`
`13386`	`13386`	`return errorType;`
`13387`	`13387`	`}`
`13388`	`13388`	`}`