Port PR #30877 (#30904)

Ports #30877 to release-3.4
microsoft · Apr 16, 2019 · 4c6ac3e · 4c6ac3e
1 parent 95e649a
commit 4c6ac3e
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Showing 5 changed files with 99 additions and 2 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -10163,15 +10163,15 @@ namespace ts {
 
         function getConditionalTypeWorker(root: ConditionalRoot, mapper: TypeMapper | undefined, checkType: Type, extendsType: Type, trueType: Type, falseType: Type) {
             // Simplifications for types of the form `T extends U ? T : never` and `T extends U ? never : T`.
-            if (falseType.flags & TypeFlags.Never && isTypeIdenticalTo(getActualTypeVariable(trueType), getActualTypeVariable(checkType))) {
+            if (falseType.flags & TypeFlags.Never && getActualTypeVariable(trueType) === getActualTypeVariable(checkType)) {
                 if (checkType.flags & TypeFlags.Any || isTypeAssignableTo(getRestrictiveInstantiation(checkType), getRestrictiveInstantiation(extendsType))) { // Always true
                     return trueType;
                 }
                 else if (isIntersectionEmpty(checkType, extendsType)) { // Always false
                     return neverType;
                 }
             }
-            else if (trueType.flags & TypeFlags.Never && isTypeIdenticalTo(getActualTypeVariable(falseType), getActualTypeVariable(checkType))) {
+            else if (trueType.flags & TypeFlags.Never && getActualTypeVariable(falseType) === getActualTypeVariable(checkType)) {
                 if (!(checkType.flags & TypeFlags.Any) && isTypeAssignableTo(getRestrictiveInstantiation(checkType), getRestrictiveInstantiation(extendsType))) { // Always true
                     return neverType;
                 }

diff --git a/tests/baselines/reference/conditionalTypeSimplification.js b/tests/baselines/reference/conditionalTypeSimplification.js
@@ -0,0 +1,15 @@
+//// [conditionalTypeSimplification.ts]
+// Repro from #30794
+
+interface AbstractSchema<S, V> {
+  m1<T> (v: T): SchemaType<S, Exclude<V, T>>;
+  m2<T> (v: T): SchemaType<S, T>;
+}
+
+type SchemaType<S, V> = S extends object ? AnySchema<V> : never;
+interface AnySchema<V> extends AnySchemaType<AnySchema<undefined>, V> { }
+interface AnySchemaType<S extends AbstractSchema<any, any>, V> extends AbstractSchema<S, V> { }
+
+
+//// [conditionalTypeSimplification.js]
+// Repro from #30794
diff --git a/tests/baselines/reference/conditionalTypeSimplification.symbols b/tests/baselines/reference/conditionalTypeSimplification.symbols
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/conditionalTypeSimplification.ts ===
+// Repro from #30794
+
+interface AbstractSchema<S, V> {
+>AbstractSchema : Symbol(AbstractSchema, Decl(conditionalTypeSimplification.ts, 0, 0))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 2, 25))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 2, 27))
+
+  m1<T> (v: T): SchemaType<S, Exclude<V, T>>;
+>m1 : Symbol(AbstractSchema.m1, Decl(conditionalTypeSimplification.ts, 2, 32))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 3, 5))
+>v : Symbol(v, Decl(conditionalTypeSimplification.ts, 3, 9))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 3, 5))
+>SchemaType : Symbol(SchemaType, Decl(conditionalTypeSimplification.ts, 5, 1))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 2, 25))
+>Exclude : Symbol(Exclude, Decl(lib.es5.d.ts, --, --))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 2, 27))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 3, 5))
+
+  m2<T> (v: T): SchemaType<S, T>;
+>m2 : Symbol(AbstractSchema.m2, Decl(conditionalTypeSimplification.ts, 3, 45))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 4, 5))
+>v : Symbol(v, Decl(conditionalTypeSimplification.ts, 4, 9))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 4, 5))
+>SchemaType : Symbol(SchemaType, Decl(conditionalTypeSimplification.ts, 5, 1))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 2, 25))
+>T : Symbol(T, Decl(conditionalTypeSimplification.ts, 4, 5))
+}
+
+type SchemaType<S, V> = S extends object ? AnySchema<V> : never;
+>SchemaType : Symbol(SchemaType, Decl(conditionalTypeSimplification.ts, 5, 1))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 7, 16))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 7, 18))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 7, 16))
+>AnySchema : Symbol(AnySchema, Decl(conditionalTypeSimplification.ts, 7, 64))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 7, 18))
+
+interface AnySchema<V> extends AnySchemaType<AnySchema<undefined>, V> { }
+>AnySchema : Symbol(AnySchema, Decl(conditionalTypeSimplification.ts, 7, 64))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 8, 20))
+>AnySchemaType : Symbol(AnySchemaType, Decl(conditionalTypeSimplification.ts, 8, 73))
+>AnySchema : Symbol(AnySchema, Decl(conditionalTypeSimplification.ts, 7, 64))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 8, 20))
+
+interface AnySchemaType<S extends AbstractSchema<any, any>, V> extends AbstractSchema<S, V> { }
+>AnySchemaType : Symbol(AnySchemaType, Decl(conditionalTypeSimplification.ts, 8, 73))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 9, 24))
+>AbstractSchema : Symbol(AbstractSchema, Decl(conditionalTypeSimplification.ts, 0, 0))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 9, 59))
+>AbstractSchema : Symbol(AbstractSchema, Decl(conditionalTypeSimplification.ts, 0, 0))
+>S : Symbol(S, Decl(conditionalTypeSimplification.ts, 9, 24))
+>V : Symbol(V, Decl(conditionalTypeSimplification.ts, 9, 59))
+
diff --git a/tests/baselines/reference/conditionalTypeSimplification.types b/tests/baselines/reference/conditionalTypeSimplification.types
@@ -0,0 +1,19 @@
+=== tests/cases/compiler/conditionalTypeSimplification.ts ===
+// Repro from #30794
+
+interface AbstractSchema<S, V> {
+  m1<T> (v: T): SchemaType<S, Exclude<V, T>>;
+>m1 : <T>(v: T) => SchemaType<S, Exclude<V, T>>
+>v : T
+
+  m2<T> (v: T): SchemaType<S, T>;
+>m2 : <T>(v: T) => SchemaType<S, T>
+>v : T
+}
+
+type SchemaType<S, V> = S extends object ? AnySchema<V> : never;
+>SchemaType : SchemaType<S, V>
+
+interface AnySchema<V> extends AnySchemaType<AnySchema<undefined>, V> { }
+interface AnySchemaType<S extends AbstractSchema<any, any>, V> extends AbstractSchema<S, V> { }
+
diff --git a/tests/cases/compiler/conditionalTypeSimplification.ts b/tests/cases/compiler/conditionalTypeSimplification.ts
@@ -0,0 +1,10 @@
+// Repro from #30794
+
+interface AbstractSchema<S, V> {
+  m1<T> (v: T): SchemaType<S, Exclude<V, T>>;
+  m2<T> (v: T): SchemaType<S, T>;
+}
+
+type SchemaType<S, V> = S extends object ? AnySchema<V> : never;
+interface AnySchema<V> extends AnySchemaType<AnySchema<undefined>, V> { }
+interface AnySchemaType<S extends AbstractSchema<any, any>, V> extends AbstractSchema<S, V> { }