Merge pull request microsoft#8770 from Microsoft/apparent-members-for-type-parameters-constrained-by-any

Apparent members for type parameters constrained by any

Author: sandersn

src/compiler/checker.ts

@@ -9955,9 +9955,9 @@ namespace ts {
  }
 
  const apparentType = getApparentType(getWidenedType(type));
- if (apparentType === unknownType) {
- // handle cases when type is Type parameter with invalid constraint
- return unknownType;
+ if (apparentType === unknownType || (type.flags & TypeFlags.TypeParameter && isTypeAny(apparentType))) {
+ // handle cases when type is Type parameter with invalid or any constraint
+ return apparentType;
  }
  const prop = getPropertyOfType(apparentType, right.text);
  if (!prop) {
@@ -11148,7 +11148,9 @@ namespace ts {
  // types are provided for the argument expressions, and the result is always of type Any.
  // We exclude union types because we may have a union of function types that happen to have
  // no common signatures.
- if (isTypeAny(funcType) || (!callSignatures.length && !constructSignatures.length && !(funcType.flags & TypeFlags.Union) && isTypeAssignableTo(funcType, globalFunctionType))) {
+ if (isTypeAny(funcType) ||
+ (isTypeAny(apparentType) && funcType.flags & TypeFlags.TypeParameter) ||
+ (!callSignatures.length && !constructSignatures.length && !(funcType.flags & TypeFlags.Union) && isTypeAssignableTo(funcType, globalFunctionType))) {
  // The unknownType indicates that an error already occurred (and was reported). No
  // need to report another error in this case.
  if (funcType !== unknownType && node.typeArguments) {

tests/baselines/reference/typeParameterExplicitlyExtendsAny.errors.txt

@@ -1,9 +1,7 @@
 tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts(3,7): error TS2339: Property 'blah' does not exist on type 'T'.
-tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts(9,7): error TS2339: Property 'blah' does not exist on type 'T'.
-tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts(10,7): error TS2339: Property 'toString' does not exist on type 'T'.
 
 
-==== tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts (3 errors) ====
+==== tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts (1 errors) ====
  function fee<T>() {
  var t: T;
  t.blah; // Error
@@ -14,10 +12,28 @@ tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts(10,7): error TS2339: P
 
  function fee2<T extends any>() {
  var t: T;
- t.blah; // Error
- ~~~~
-!!! error TS2339: Property 'blah' does not exist on type 'T'.
+ t.blah; // ok
  t.toString; // ok
- ~~~~~~~~
-!!! error TS2339: Property 'toString' does not exist on type 'T'.
- }
+ }
+ 
+ function f<T extends any>(x: T) {
+ x.children;
+ x();
+ new x();
+ x[100];
+ x['hello'];
+ }
+ 
+ 
+ // Generic Tree structure
+ type Tree<T> = T & {
+ children?: Tree<T>[];
+ }
+ 
+ class MyClass {
+ public static displayTree1<T extends Tree<any>>(tree: T) {
+ // error "Property 'children' does not exist on type 'T'"
+ tree.children;
+ }
+ }
+ 

tests/baselines/reference/typeParameterExplicitlyExtendsAny.js

@@ -7,9 +7,31 @@ function fee<T>() {
 
 function fee2<T extends any>() {
  var t: T;
- t.blah; // Error
+ t.blah; // ok
  t.toString; // ok
-}
+}
+
+function f<T extends any>(x: T) {
+ x.children;
+ x();
+ new x();
+ x[100];
+ x['hello'];
+}
+
+
+// Generic Tree structure
+type Tree<T> = T & {
+ children?: Tree<T>[];
+}
+
+class MyClass {
+ public static displayTree1<T extends Tree<any>>(tree: T) {
+ // error "Property 'children' does not exist on type 'T'"
+ tree.children;
+ }
+}
+
 
 //// [typeParameterExplicitlyExtendsAny.js]
 function fee() {
@@ -19,6 +41,22 @@ function fee() {
 }
 function fee2() {
  var t;
- t.blah; // Error
+ t.blah; // ok
  t.toString; // ok
 }
+function f(x) {
+ x.children;
+ x();
+ new x();
+ x[100];
+ x['hello'];
+}
+var MyClass = (function () {
+ function MyClass() {
+ }
+ MyClass.displayTree1 = function (tree) {
+ // error "Property 'children' does not exist on type 'T'"
+ tree.children;
+ };
+ return MyClass;
+}());

tests/cases/compiler/typeParameterExplicitlyExtendsAny.ts

@@ -6,6 +6,27 @@ function fee<T>() {
 
 function fee2<T extends any>() {
  var t: T;
- t.blah; // Error
+ t.blah; // ok
  t.toString; // ok
-}
+}
+
+function f<T extends any>(x: T) {
+ x.children;
+ x();
+ new x();
+ x[100];
+ x['hello'];
+}
+
+
+// Generic Tree structure
+type Tree<T> = T & {
+ children?: Tree<T>[];
+}
+
+class MyClass {
+ public static displayTree1<T extends Tree<any>>(tree: T) {
+ // error "Property 'children' does not exist on type 'T'"
+ tree.children;
+ }
+}