Check other cases

jack-williams · jack-williams · commit a3062b6510fa · 2019-11-03T15:08:56.000Z
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -19319,7 +19319,7 @@ namespace ts {
                 if (isMatchingReference(reference, expr)) {
                     return getTypeWithFacts(type, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy);
                 }
-                if (isMatchingReferenceDiscriminant(expr, declaredType)) {
+                if (isMatchingReferenceDiscriminant(expr, containingUnion || declaredType)) {
                     return narrowTypeByDiscriminant(type, <AccessExpression>expr, t => getTypeWithFacts(t, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy));
                 }
                 if (containsMatchingReferenceDiscriminant(reference, expr)) {
@@ -19795,7 +19795,7 @@ namespace ts {
                 if (isMatchingReference(reference, expr)) {
                     return getTypeWithFacts(type, assumePresent ? TypeFacts.NEUndefinedOrNull : TypeFacts.EQUndefinedOrNull);
                 }
-                if (isMatchingReferenceDiscriminant(expr, declaredType)) {
+                if (isMatchingReferenceDiscriminant(expr, containingUnion || declaredType)) {
                     return narrowTypeByDiscriminant(type, <AccessExpression>expr, t => getTypeWithFacts(t, assumePresent ? TypeFacts.NEUndefinedOrNull : TypeFacts.EQUndefinedOrNull));
                 }
                 if (containsMatchingReferenceDiscriminant(reference, expr)) {

Original file line number	Diff line number	Diff line change
`@@ -19319,7 +19319,7 @@ namespace ts {`
`19319`	`19319`	`if (isMatchingReference(reference, expr)) {`
`19320`	`19320`	`return getTypeWithFacts(type, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy);`
`19321`	`19321`	`}`
`19322`		`- if (isMatchingReferenceDiscriminant(expr, declaredType)) {`
	`19322`	`+ if (isMatchingReferenceDiscriminant(expr, containingUnion \|\| declaredType)) {`
`19323`	`19323`	`return narrowTypeByDiscriminant(type, <AccessExpression>expr, t => getTypeWithFacts(t, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy));`
`19324`	`19324`	`}`
`19325`	`19325`	`if (containsMatchingReferenceDiscriminant(reference, expr)) {`
`@@ -19795,7 +19795,7 @@ namespace ts {`
`19795`	`19795`	`if (isMatchingReference(reference, expr)) {`
`19796`	`19796`	`return getTypeWithFacts(type, assumePresent ? TypeFacts.NEUndefinedOrNull : TypeFacts.EQUndefinedOrNull);`
`19797`	`19797`	`}`
`19798`		`- if (isMatchingReferenceDiscriminant(expr, declaredType)) {`
	`19798`	`+ if (isMatchingReferenceDiscriminant(expr, containingUnion \|\| declaredType)) {`
`19799`	`19799`	`return narrowTypeByDiscriminant(type, <AccessExpression>expr, t => getTypeWithFacts(t, assumePresent ? TypeFacts.NEUndefinedOrNull : TypeFacts.EQUndefinedOrNull));`
`19800`	`19800`	`}`
`19801`	`19801`	`if (containsMatchingReferenceDiscriminant(reference, expr)) {`