Add test

tests/baselines/reference/strictFunctionTypesErrors.errors.txt

@@ -83,9 +83,18 @@ tests/cases/compiler/strictFunctionTypesErrors.ts(126,1): error TS2322: Type 'Cr
 tests/cases/compiler/strictFunctionTypesErrors.ts(127,1): error TS2322: Type 'Crate<Animal>' is not assignable to type 'Crate<Dog>'.
   Types of property 'item' are incompatible.
     Type 'Animal' is not assignable to type 'Dog'.
+tests/cases/compiler/strictFunctionTypesErrors.ts(133,1): error TS2322: Type '(f: (x: Dog) => Dog) => void' is not assignable to type '(f: (x: Animal) => Animal) => void'.
+  Types of parameters 'f' and 'f' are incompatible.
+    Type '(x: Animal) => Animal' is not assignable to type '(x: Dog) => Dog'.
+      Type 'Animal' is not assignable to type 'Dog'.
+tests/cases/compiler/strictFunctionTypesErrors.ts(134,1): error TS2322: Type '(f: (x: Animal) => Animal) => void' is not assignable to type '(f: (x: Dog) => Dog) => void'.
+  Types of parameters 'f' and 'f' are incompatible.
+    Type '(x: Dog) => Dog' is not assignable to type '(x: Animal) => Animal'.
+      Types of parameters 'x' and 'x' are incompatible.
+        Type 'Animal' is not assignable to type 'Dog'.
 
 
-==== tests/cases/compiler/strictFunctionTypesErrors.ts (31 errors) ====
+==== tests/cases/compiler/strictFunctionTypesErrors.ts (33 errors) ====
     export {}
     
     
@@ -329,4 +338,22 @@ tests/cases/compiler/strictFunctionTypesErrors.ts(127,1): error TS2322: Type 'Cr
 !!! error TS2322: Type 'Crate<Animal>' is not assignable to type 'Crate<Dog>'.
 !!! error TS2322:   Types of property 'item' are incompatible.
 !!! error TS2322:     Type 'Animal' is not assignable to type 'Dog'.
+    
+    // Verify that callback parameters are strictly checked
+    
+    declare let fc1: (f: (x: Animal) => Animal) => void;
+    declare let fc2: (f: (x: Dog) => Dog) => void;
+    fc1 = fc2;  // Error
+    ~~~
+!!! error TS2322: Type '(f: (x: Dog) => Dog) => void' is not assignable to type '(f: (x: Animal) => Animal) => void'.
+!!! error TS2322:   Types of parameters 'f' and 'f' are incompatible.
+!!! error TS2322:     Type '(x: Animal) => Animal' is not assignable to type '(x: Dog) => Dog'.
+!!! error TS2322:       Type 'Animal' is not assignable to type 'Dog'.
+    fc2 = fc1;  // Error
+    ~~~
+!!! error TS2322: Type '(f: (x: Animal) => Animal) => void' is not assignable to type '(f: (x: Dog) => Dog) => void'.
+!!! error TS2322:   Types of parameters 'f' and 'f' are incompatible.
+!!! error TS2322:     Type '(x: Dog) => Dog' is not assignable to type '(x: Animal) => Animal'.
+!!! error TS2322:       Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:         Type 'Animal' is not assignable to type 'Dog'.
     

tests/baselines/reference/strictFunctionTypesErrors.js

@@ -126,6 +126,13 @@ declare let dogCrate: Crate<Dog>;
 
 animalCrate = dogCrate;  // Error
 dogCrate = animalCrate;  // Error
+
+// Verify that callback parameters are strictly checked
+
+declare let fc1: (f: (x: Animal) => Animal) => void;
+declare let fc2: (f: (x: Dog) => Dog) => void;
+fc1 = fc2;  // Error
+fc2 = fc1;  // Error
 
 
 //// [strictFunctionTypesErrors.js]
@@ -186,3 +193,5 @@ dogComparer2 = animalComparer2; // Ok
 // Errors below should elaborate the reason for invariance
 animalCrate = dogCrate; // Error
 dogCrate = animalCrate; // Error
+fc1 = fc2; // Error
+fc2 = fc1; // Error

tests/baselines/reference/strictFunctionTypesErrors.symbols

@@ -400,3 +400,27 @@ dogCrate = animalCrate;  // Error
 >dogCrate : Symbol(dogCrate, Decl(strictFunctionTypesErrors.ts, 121, 11))
 >animalCrate : Symbol(animalCrate, Decl(strictFunctionTypesErrors.ts, 120, 11))
 
+// Verify that callback parameters are strictly checked
+
+declare let fc1: (f: (x: Animal) => Animal) => void;
+>fc1 : Symbol(fc1, Decl(strictFunctionTypesErrors.ts, 130, 11))
+>f : Symbol(f, Decl(strictFunctionTypesErrors.ts, 130, 18))
+>x : Symbol(x, Decl(strictFunctionTypesErrors.ts, 130, 22))
+>Animal : Symbol(Animal, Decl(strictFunctionTypesErrors.ts, 87, 8))
+>Animal : Symbol(Animal, Decl(strictFunctionTypesErrors.ts, 87, 8))
+
+declare let fc2: (f: (x: Dog) => Dog) => void;
+>fc2 : Symbol(fc2, Decl(strictFunctionTypesErrors.ts, 131, 11))
+>f : Symbol(f, Decl(strictFunctionTypesErrors.ts, 131, 18))
+>x : Symbol(x, Decl(strictFunctionTypesErrors.ts, 131, 22))
+>Dog : Symbol(Dog, Decl(strictFunctionTypesErrors.ts, 89, 33))
+>Dog : Symbol(Dog, Decl(strictFunctionTypesErrors.ts, 89, 33))
+
+fc1 = fc2;  // Error
+>fc1 : Symbol(fc1, Decl(strictFunctionTypesErrors.ts, 130, 11))
+>fc2 : Symbol(fc2, Decl(strictFunctionTypesErrors.ts, 131, 11))
+
+fc2 = fc1;  // Error
+>fc2 : Symbol(fc2, Decl(strictFunctionTypesErrors.ts, 131, 11))
+>fc1 : Symbol(fc1, Decl(strictFunctionTypesErrors.ts, 130, 11))
+

tests/baselines/reference/strictFunctionTypesErrors.types

@@ -454,3 +454,29 @@ dogCrate = animalCrate;  // Error
 >dogCrate : Crate<Dog>
 >animalCrate : Crate<Animal>
 
+// Verify that callback parameters are strictly checked
+
+declare let fc1: (f: (x: Animal) => Animal) => void;
+>fc1 : (f: (x: Animal) => Animal) => void
+>f : (x: Animal) => Animal
+>x : Animal
+>Animal : Animal
+>Animal : Animal
+
+declare let fc2: (f: (x: Dog) => Dog) => void;
+>fc2 : (f: (x: Dog) => Dog) => void
+>f : (x: Dog) => Dog
+>x : Dog
+>Dog : Dog
+>Dog : Dog
+
+fc1 = fc2;  // Error
+>fc1 = fc2 : (f: (x: Dog) => Dog) => void
+>fc1 : (f: (x: Animal) => Animal) => void
+>fc2 : (f: (x: Dog) => Dog) => void
+
+fc2 = fc1;  // Error
+>fc2 = fc1 : (f: (x: Animal) => Animal) => void
+>fc2 : (f: (x: Dog) => Dog) => void
+>fc1 : (f: (x: Animal) => Animal) => void
+

tests/cases/compiler/strictFunctionTypesErrors.ts

@@ -126,3 +126,10 @@ declare let dogCrate: Crate<Dog>;
 
 animalCrate = dogCrate;  // Error
 dogCrate = animalCrate;  // Error
+
+// Verify that callback parameters are strictly checked
+
+declare let fc1: (f: (x: Animal) => Animal) => void;
+declare let fc2: (f: (x: Dog) => Dog) => void;
+fc1 = fc2;  // Error
+fc2 = fc1;  // Error