Merge pull request microsoft#7328 from Microsoft/flipSidesInSignatureCheck

flip sides source and target when we check signature relations

Author: vladima

src/compiler/checker.ts

@@ -5337,7 +5337,7 @@ namespace ts {
  for (let i = 0; i < checkCount; i++) {
  const s = i < sourceMax ? getTypeOfSymbol(sourceParams[i]) : getRestTypeOfSignature(source);
  const t = i < targetMax ? getTypeOfSymbol(targetParams[i]) : getRestTypeOfSignature(target);
- const related = compareTypes(t, s, /*reportErrors*/ false) || compareTypes(s, t, reportErrors);
+ const related = compareTypes(s, t, /*reportErrors*/ false) || compareTypes(t, s, reportErrors);
  if (!related) {
  if (reportErrors) {
  errorReporter(Diagnostics.Types_of_parameters_0_and_1_are_incompatible,

tests/baselines/reference/arrayLiterals3.errors.txt

@@ -16,8 +16,8 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
  Types of property 'push' are incompatible.
  Type '(...items: (number | string)[]) => number' is not assignable to type '(...items: Number[]) => number'.
  Types of parameters 'items' and 'items' are incompatible.
- Type 'number | string' is not assignable to type 'Number'.
- Type 'string' is not assignable to type 'Number'.
+ Type 'Number' is not assignable to type 'number | string'.
+ Type 'Number' is not assignable to type 'string'.
 
 
 ==== tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts (6 errors) ====
@@ -79,6 +79,6 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
 !!! error TS2322: Types of property 'push' are incompatible.
 !!! error TS2322: Type '(...items: (number | string)[]) => number' is not assignable to type '(...items: Number[]) => number'.
 !!! error TS2322: Types of parameters 'items' and 'items' are incompatible.
-!!! error TS2322: Type 'number | string' is not assignable to type 'Number'.
-!!! error TS2322: Type 'string' is not assignable to type 'Number'.
+!!! error TS2322: Type 'Number' is not assignable to type 'number | string'.
+!!! error TS2322: Type 'Number' is not assignable to type 'string'.
 

tests/baselines/reference/assignmentCompatBug5.errors.txt

@@ -4,7 +4,7 @@ tests/cases/compiler/assignmentCompatBug5.ts(5,6): error TS2345: Argument of typ
  Type 'string' is not assignable to type 'number'.
 tests/cases/compiler/assignmentCompatBug5.ts(8,6): error TS2345: Argument of type '(s: string) => void' is not assignable to parameter of type '(n: number) => number'.
  Types of parameters 's' and 'n' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/assignmentCompatBug5.ts(9,6): error TS2345: Argument of type '(n: number) => void' is not assignable to parameter of type '(n: number) => number'.
  Type 'void' is not assignable to type 'number'.
 
@@ -27,7 +27,7 @@ tests/cases/compiler/assignmentCompatBug5.ts(9,6): error TS2345: Argument of typ
  ~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '(s: string) => void' is not assignable to parameter of type '(n: number) => number'.
 !!! error TS2345: Types of parameters 's' and 'n' are incompatible.
-!!! error TS2345: Type 'string' is not assignable to type 'number'.
+!!! error TS2345: Type 'number' is not assignable to type 'string'.
  foo3((n) => { return; });
  ~~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '(n: number) => void' is not assignable to parameter of type '(n: number) => number'.

tests/baselines/reference/assignmentCompatWithCallSignatures.errors.txt

@@ -1,27 +1,27 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(35,1): error TS2322: Type 'S2' is not assignable to type 'T'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(36,1): error TS2322: Type '(x: string) => void' is not assignable to type 'T'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(37,1): error TS2322: Type '(x: string) => number' is not assignable to type 'T'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(38,1): error TS2322: Type '(x: string) => string' is not assignable to type 'T'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(39,1): error TS2322: Type 'S2' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(40,1): error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(41,1): error TS2322: Type '(x: string) => number' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts(42,1): error TS2322: Type '(x: string) => string' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures.ts (8 errors) ====
@@ -63,40 +63,40 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
  ~
 !!! error TS2322: Type 'S2' is not assignable to type 'T'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  t = a3;
  ~
 !!! error TS2322: Type '(x: string) => void' is not assignable to type 'T'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  t = (x: string) => 1;
  ~
 !!! error TS2322: Type '(x: string) => number' is not assignable to type 'T'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  t = function (x: string) { return ''; }
  ~
 !!! error TS2322: Type '(x: string) => string' is not assignable to type 'T'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = s2;
  ~
 !!! error TS2322: Type 'S2' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = a3;
  ~
 !!! error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = (x: string) => 1;
  ~
 !!! error TS2322: Type '(x: string) => number' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = function (x: string) { return ''; }
  ~
 !!! error TS2322: Type '(x: string) => string' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
 

tests/baselines/reference/assignmentCompatWithCallSignatures2.errors.txt

@@ -10,12 +10,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
  Types of property 'f' are incompatible.
  Type '(x: string) => void' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(43,1): error TS2322: Type '{ f(x: string): void; }' is not assignable to type 'T'.
  Types of property 'f' are incompatible.
  Type '(x: string) => void' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(44,1): error TS2322: Type '(x: string) => number' is not assignable to type 'T'.
  Property 'f' is missing in type '(x: string) => number'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(45,1): error TS2322: Type '(x: string) => string' is not assignable to type 'T'.
@@ -24,12 +24,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
  Types of property 'f' are incompatible.
  Type '(x: string) => void' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(47,1): error TS2322: Type '{ f(x: string): void; }' is not assignable to type '{ f(x: number): void; }'.
  Types of property 'f' are incompatible.
  Type '(x: string) => void' is not assignable to type '(x: number) => void'.
  Types of parameters 'x' and 'x' are incompatible.
- Type 'string' is not assignable to type 'number'.
+ Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(48,1): error TS2322: Type '(x: string) => number' is not assignable to type '{ f(x: number): void; }'.
  Property 'f' is missing in type '(x: string) => number'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures2.ts(49,1): error TS2322: Type '(x: string) => string' is not assignable to type '{ f(x: number): void; }'.
@@ -96,14 +96,14 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 !!! error TS2322: Types of property 'f' are incompatible.
 !!! error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  t = a3;
  ~
 !!! error TS2322: Type '{ f(x: string): void; }' is not assignable to type 'T'.
 !!! error TS2322: Types of property 'f' are incompatible.
 !!! error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  t = (x: string) => 1;
  ~
 !!! error TS2322: Type '(x: string) => number' is not assignable to type 'T'.
@@ -118,14 +118,14 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 !!! error TS2322: Types of property 'f' are incompatible.
 !!! error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = a3;
  ~
 !!! error TS2322: Type '{ f(x: string): void; }' is not assignable to type '{ f(x: number): void; }'.
 !!! error TS2322: Types of property 'f' are incompatible.
 !!! error TS2322: Type '(x: string) => void' is not assignable to type '(x: number) => void'.
 !!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
  a = (x: string) => 1;
  ~
 !!! error TS2322: Type '(x: string) => number' is not assignable to type '{ f(x: number): void; }'.

tests/baselines/reference/assignmentCompatWithCallSignatures4.errors.txt

@@ -1,13 +1,13 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(52,9): error TS2322: Type '<T extends Base, U extends Derived>(x: (arg: T) => U, y: (arg2: { foo: number; }) => U) => (r: T) => U' is not assignable to type '(x: (arg: Base) => Derived, y: (arg2: Base) => Derived) => (r: Base) => Derived'.
  Types of parameters 'y' and 'y' are incompatible.
- Type '(arg2: { foo: number; }) => any' is not assignable to type '(arg2: Base) => Derived'.
+ Type '(arg2: Base) => Derived' is not assignable to type '(arg2: { foo: number; }) => any'.
  Types of parameters 'arg2' and 'arg2' are incompatible.
  Type '{ foo: number; }' is not assignable to type 'Base'.
  Types of property 'foo' are incompatible.
  Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(53,9): error TS2322: Type '(x: (arg: Base) => Derived, y: (arg2: Base) => Derived) => (r: Base) => Derived' is not assignable to type '<T extends Base, U extends Derived>(x: (arg: T) => U, y: (arg2: { foo: number; }) => U) => (r: T) => U'.
  Types of parameters 'y' and 'y' are incompatible.
- Type '(arg2: Base) => Derived' is not assignable to type '(arg2: { foo: number; }) => any'.
+ Type '(arg2: { foo: number; }) => any' is not assignable to type '(arg2: Base) => Derived'.
  Types of parameters 'arg2' and 'arg2' are incompatible.
  Type 'Base' is not assignable to type '{ foo: number; }'.
  Types of property 'foo' are incompatible.
@@ -70,7 +70,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
  ~~
 !!! error TS2322: Type '<T extends Base, U extends Derived>(x: (arg: T) => U, y: (arg2: { foo: number; }) => U) => (r: T) => U' is not assignable to type '(x: (arg: Base) => Derived, y: (arg2: Base) => Derived) => (r: Base) => Derived'.
 !!! error TS2322: Types of parameters 'y' and 'y' are incompatible.
-!!! error TS2322: Type '(arg2: { foo: number; }) => any' is not assignable to type '(arg2: Base) => Derived'.
+!!! error TS2322: Type '(arg2: Base) => Derived' is not assignable to type '(arg2: { foo: number; }) => any'.
 !!! error TS2322: Types of parameters 'arg2' and 'arg2' are incompatible.
 !!! error TS2322: Type '{ foo: number; }' is not assignable to type 'Base'.
 !!! error TS2322: Types of property 'foo' are incompatible.
@@ -79,7 +79,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
  ~~
 !!! error TS2322: Type '(x: (arg: Base) => Derived, y: (arg2: Base) => Derived) => (r: Base) => Derived' is not assignable to type '<T extends Base, U extends Derived>(x: (arg: T) => U, y: (arg2: { foo: number; }) => U) => (r: T) => U'.
 !!! error TS2322: Types of parameters 'y' and 'y' are incompatible.
-!!! error TS2322: Type '(arg2: Base) => Derived' is not assignable to type '(arg2: { foo: number; }) => any'.
+!!! error TS2322: Type '(arg2: { foo: number; }) => any' is not assignable to type '(arg2: Base) => Derived'.
 !!! error TS2322: Types of parameters 'arg2' and 'arg2' are incompatible.
 !!! error TS2322: Type 'Base' is not assignable to type '{ foo: number; }'.
 !!! error TS2322: Types of property 'foo' are incompatible.