Only widen fresh literal types in CFA of assignment to auto-typed

ahejlsberg · ahejlsberg · commit 728d9cb91172 · 2020-04-15T18:25:14.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -20150,7 +20150,7 @@ namespace ts {
                         if (isEmptyArrayAssignment(node)) {
                             return getEvolvingArrayType(neverType);
                         }
-                        const assignedType = getBaseTypeOfLiteralType(getInitialOrAssignedType(flow));
+                        const assignedType = getWidenedLiteralType(getInitialOrAssignedType(flow));
                         return isTypeAssignableTo(assignedType, declaredType) ? assignedType : anyArrayType;
                     }
                     if (declaredType.flags & TypeFlags.Union) {

Original file line number	Diff line number	Diff line change
`@@ -20150,7 +20150,7 @@ namespace ts {`
`20150`	`20150`	`if (isEmptyArrayAssignment(node)) {`
`20151`	`20151`	`return getEvolvingArrayType(neverType);`
`20152`	`20152`	`}`
`20153`		`- const assignedType = getBaseTypeOfLiteralType(getInitialOrAssignedType(flow));`
	`20153`	`+ const assignedType = getWidenedLiteralType(getInitialOrAssignedType(flow));`
`20154`	`20154`	`return isTypeAssignableTo(assignedType, declaredType) ? assignedType : anyArrayType;`
`20155`	`20155`	`}`
`20156`	`20156`	`if (declaredType.flags & TypeFlags.Union) {`