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Test cases of function infering return type of functions

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if f is a contextually typed function expression (section 4.9.3), the inferred return type is the union type (section 3.3.4) of the types of the return statement expressions in the function body, ignoring return statements with no expressions.
Otherwise, the inferred return type is the first of the types of the return statement expressions in the function body that is a supertype (section 3.8.3) of each of the others, ignoring return statements with no expressions. A compile-time error occurs if no return statement expression has a type that is a supertype of each of the others.
This commit is contained in:
Sheetal Nandi
2014-11-04 16:40:56 -08:00
parent 40af15c8ff
commit 9d31631fd7
6 changed files with 400 additions and 6 deletions
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67
tests/baselines/reference/functionImplementationErrors.errors.txt
View File

@@ -6,9 +6,15 @@ tests/cases/conformance/functions/functionImplementationErrors.ts(25,16): error
tests/cases/conformance/functions/functionImplementationErrors.ts(30,17): error TS2373: Initializer of parameter 'n' cannot reference identifier 'm' declared after it.
tests/cases/conformance/functions/functionImplementationErrors.ts(35,17): error TS2373: Initializer of parameter 'n' cannot reference identifier 'm' declared after it.
tests/cases/conformance/functions/functionImplementationErrors.ts(40,28): error TS2355: A function whose declared type is neither 'void' nor 'any' must return a value or consist of a single 'throw' statement.
tests/cases/conformance/functions/functionImplementationErrors.ts(49,1): error TS2354: No best common type exists among return expressions.
tests/cases/conformance/functions/functionImplementationErrors.ts(53,10): error TS2354: No best common type exists among return expressions.
tests/cases/conformance/functions/functionImplementationErrors.ts(57,11): error TS2354: No best common type exists among return expressions.
tests/cases/conformance/functions/functionImplementationErrors.ts(61,1): error TS2354: No best common type exists among return expressions.
tests/cases/conformance/functions/functionImplementationErrors.ts(65,11): error TS2354: No best common type exists among return expressions.
tests/cases/conformance/functions/functionImplementationErrors.ts(69,11): error TS2354: No best common type exists among return expressions.
==== tests/cases/conformance/functions/functionImplementationErrors.ts (8 errors) ====
==== tests/cases/conformance/functions/functionImplementationErrors.ts (14 errors) ====
// FunctionExpression with no return type annotation with multiple return statements with unrelated types
var f1 = function () {
~~~~~~~~~~~~~
@@ -83,4 +89,63 @@ tests/cases/conformance/functions/functionImplementationErrors.ts(40,28): error
throw undefined;
var x = 4;
};
class Base { private x; }
class AnotherClass { private y; }
class Derived1 extends Base { private m; }
class Derived2 extends Base { private n; }
function f8() {
~~~~~~~~~~~~~~~
return new Derived1();
~~~~~~~~~~~~~~~~~~~~~~~~~~
return new Derived2();
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
}
~
!!! error TS2354: No best common type exists among return expressions.
var f9 = function () {
~~~~~~~~~~~~~
return new Derived1();
~~~~~~~~~~~~~~~~~~~~~~~~~~
return new Derived2();
~~~~~~~~~~~~~~~~~~~~~~~~~~
};
~
!!! error TS2354: No best common type exists among return expressions.
var f10 = () => {
~~~~~~~
return new Derived1();
~~~~~~~~~~~~~~~~~~~~~~~~~~
return new Derived2();
~~~~~~~~~~~~~~~~~~~~~~~~~~
};
~
!!! error TS2354: No best common type exists among return expressions.
function f11() {
~~~~~~~~~~~~~~~~
return new Base();
~~~~~~~~~~~~~~~~~~~~~~
return new AnotherClass();
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
}
~
!!! error TS2354: No best common type exists among return expressions.
var f12 = function () {
~~~~~~~~~~~~~
return new Base();
~~~~~~~~~~~~~~~~~~~~~~
return new AnotherClass();
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
};
~
!!! error TS2354: No best common type exists among return expressions.
var f13 = () => {
~~~~~~~
return new Base();
~~~~~~~~~~~~~~~~~~~~~~
return new AnotherClass();
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
};
~
!!! error TS2354: No best common type exists among return expressions.

83
tests/baselines/reference/functionImplementationErrors.js
View File

@@ -42,9 +42,44 @@ undefined === function (): number {
throw undefined;
var x = 4;
};
class Base { private x; }
class AnotherClass { private y; }
class Derived1 extends Base { private m; }
class Derived2 extends Base { private n; }
function f8() {
return new Derived1();
return new Derived2();
}
var f9 = function () {
return new Derived1();
return new Derived2();
};
var f10 = () => {
return new Derived1();
return new Derived2();
};
function f11() {
return new Base();
return new AnotherClass();
}
var f12 = function () {
return new Base();
return new AnotherClass();
};
var f13 = () => {
return new Base();
return new AnotherClass();
};
//// [functionImplementationErrors.js]
var __extends = this.__extends || function (d, b) {
for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
function __() { this.constructor = d; }
__.prototype = b.prototype;
d.prototype = new __();
};
// FunctionExpression with no return type annotation with multiple return statements with unrelated types
var f1 = function () {
return '';
@@ -86,3 +121,51 @@ undefined === function () {
throw undefined;
var x = 4;
};
var Base = (function () {
function Base() {
}
return Base;
})();
var AnotherClass = (function () {
function AnotherClass() {
}
return AnotherClass;
})();
var Derived1 = (function (_super) {
__extends(Derived1, _super);
function Derived1() {
_super.apply(this, arguments);
}
return Derived1;
})(Base);
var Derived2 = (function (_super) {
__extends(Derived2, _super);
function Derived2() {
_super.apply(this, arguments);
}
return Derived2;
})(Base);
function f8() {
return new Derived1();
return new Derived2();
}
var f9 = function () {
return new Derived1();
return new Derived2();
};
var f10 = function () {
return new Derived1();
return new Derived2();
};
function f11() {
return new Base();
return new AnotherClass();
}
var f12 = function () {
return new Base();
return new AnotherClass();
};
var f13 = function () {
return new Base();
return new AnotherClass();
};

85
tests/baselines/reference/functionImplementations.js
View File

@@ -70,6 +70,10 @@ var n = function () {
return 5;
}();
// Otherwise, the inferred return type is the first of the types of the return statement expressions
// in the function body that is a supertype of each of the others,
// ignoring return statements with no expressions.
// A compile - time error occurs if no return statement expression has a type that is a supertype of each of the others.
// FunctionExpression with no return type annotation with multiple return statements with subtype relation between returns
class Base { private m; }
class Derived extends Base { private q; }
@@ -120,9 +124,37 @@ function f6(): number {
return;
}
class Derived2 extends Base { private r: string; }
class AnotherClass { private x }
// if f is a contextually typed function expression, the inferred return type is the union type
// of the types of the return statement expressions in the function body,
// ignoring return statements with no expressions.
var f7: (x: number) => string | number = x => { // should be (x: number) => number | string
if (x < 0) { return x; }
return x.toString();
}
var f8: (x: number) => any = x => { // should be (x: number) => Base
return new Base();
return new Derived2();
}
var f9: (x: number) => any = x => { // should be (x: number) => Base
return new Base();
return new Derived();
return new Derived2();
}
var f10: (x: number) => any = x => { // should be (x: number) => Derived | Derived1
return new Derived();
return new Derived2();
}
var f11: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
return new Base();
return new AnotherClass();
}
var f12: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
return new Base();
return; // should be ignored
return new AnotherClass();
}
//// [functionImplementations.js]
var __extends = this.__extends || function (d, b) {
@@ -192,6 +224,10 @@ var n = function () {
return 3;
return 5;
}();
// Otherwise, the inferred return type is the first of the types of the return statement expressions
// in the function body that is a supertype of each of the others,
// ignoring return statements with no expressions.
// A compile - time error occurs if no return statement expression has a type that is a supertype of each of the others.
// FunctionExpression with no return type annotation with multiple return statements with subtype relation between returns
var Base = (function () {
function Base() {
@@ -249,3 +285,46 @@ function opt3(n, m) {
function f6() {
return;
}
var Derived2 = (function (_super) {
__extends(Derived2, _super);
function Derived2() {
_super.apply(this, arguments);
}
return Derived2;
})(Base);
var AnotherClass = (function () {
function AnotherClass() {
}
return AnotherClass;
})();
// if f is a contextually typed function expression, the inferred return type is the union type
// of the types of the return statement expressions in the function body,
// ignoring return statements with no expressions.
var f7 = function (x) {
if (x < 0) {
return x;
}
return x.toString();
};
var f8 = function (x) {
return new Base();
return new Derived2();
};
var f9 = function (x) {
return new Base();
return new Derived();
return new Derived2();
};
var f10 = function (x) {
return new Derived();
return new Derived2();
};
var f11 = function (x) {
return new Base();
return new AnotherClass();
};
var f12 = function (x) {
return new Base();
return; // should be ignored
return new AnotherClass();
};

105
tests/baselines/reference/functionImplementations.types
View File

@@ -168,6 +168,10 @@ var n = function () {
return 5;
}();
// Otherwise, the inferred return type is the first of the types of the return statement expressions
// in the function body that is a supertype of each of the others,
// ignoring return statements with no expressions.
// A compile - time error occurs if no return statement expression has a type that is a supertype of each of the others.
// FunctionExpression with no return type annotation with multiple return statements with subtype relation between returns
class Base { private m; }
>Base : Base
@@ -292,6 +296,107 @@ function f6(): number {
return;
}
class Derived2 extends Base { private r: string; }
>Derived2 : Derived2
>Base : Base
>r : string
class AnotherClass { private x }
>AnotherClass : AnotherClass
>x : any
// if f is a contextually typed function expression, the inferred return type is the union type
// of the types of the return statement expressions in the function body,
// ignoring return statements with no expressions.
var f7: (x: number) => string | number = x => { // should be (x: number) => number | string
>f7 : (x: number) => string | number
>x : number
>x => { // should be (x: number) => number | string if (x < 0) { return x; } return x.toString();} : (x: number) => string | number
>x : number
if (x < 0) { return x; }
>x < 0 : boolean
>x : number
>x : number
return x.toString();
>x.toString() : string
>x.toString : (radix?: number) => string
>x : number
>toString : (radix?: number) => string
}
var f8: (x: number) => any = x => { // should be (x: number) => Base
>f8 : (x: number) => any
>x : number
>x => { // should be (x: number) => Base return new Base(); return new Derived2();} : (x: number) => Base
>x : number
return new Base();
>new Base() : Base
>Base : typeof Base
return new Derived2();
>new Derived2() : Derived2
>Derived2 : typeof Derived2
}
var f9: (x: number) => any = x => { // should be (x: number) => Base
>f9 : (x: number) => any
>x : number
>x => { // should be (x: number) => Base return new Base(); return new Derived(); return new Derived2();} : (x: number) => Base
>x : number
return new Base();
>new Base() : Base
>Base : typeof Base
return new Derived();
>new Derived() : Derived
>Derived : typeof Derived
return new Derived2();
>new Derived2() : Derived2
>Derived2 : typeof Derived2
}
var f10: (x: number) => any = x => { // should be (x: number) => Derived | Derived1
>f10 : (x: number) => any
>x : number
>x => { // should be (x: number) => Derived | Derived1 return new Derived(); return new Derived2();} : (x: number) => Derived | Derived2
>x : number
return new Derived();
>new Derived() : Derived
>Derived : typeof Derived
return new Derived2();
>new Derived2() : Derived2
>Derived2 : typeof Derived2
}
var f11: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
>f11 : (x: number) => any
>x : number
>x => { // should be (x: number) => Base | AnotherClass return new Base(); return new AnotherClass();} : (x: number) => Base | AnotherClass
>x : number
return new Base();
>new Base() : Base
>Base : typeof Base
return new AnotherClass();
>new AnotherClass() : AnotherClass
>AnotherClass : typeof AnotherClass
}
var f12: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
>f12 : (x: number) => any
>x : number
>x => { // should be (x: number) => Base | AnotherClass return new Base(); return; // should be ignored return new AnotherClass();} : (x: number) => Base | AnotherClass
>x : number
return new Base();
>new Base() : Base
>Base : typeof Base
return; // should be ignored
return new AnotherClass();
>new AnotherClass() : AnotherClass
>AnotherClass : typeof AnotherClass
}

29
tests/cases/conformance/functions/functionImplementationErrors.ts
View File

@@ -41,3 +41,32 @@ undefined === function (): number {
throw undefined;
var x = 4;
};
class Base { private x; }
class AnotherClass { private y; }
class Derived1 extends Base { private m; }
class Derived2 extends Base { private n; }
function f8() {
return new Derived1();
return new Derived2();
}
var f9 = function () {
return new Derived1();
return new Derived2();
};
var f10 = () => {
return new Derived1();
return new Derived2();
};
function f11() {
return new Base();
return new AnotherClass();
}
var f12 = function () {
return new Base();
return new AnotherClass();
};
var f13 = () => {
return new Base();
return new AnotherClass();
};

37
tests/cases/conformance/functions/functionImplementations.ts
View File

@@ -69,6 +69,10 @@ var n = function () {
return 5;
}();
// Otherwise, the inferred return type is the first of the types of the return statement expressions
// in the function body that is a supertype of each of the others,
// ignoring return statements with no expressions.
// A compile - time error occurs if no return statement expression has a type that is a supertype of each of the others.
// FunctionExpression with no return type annotation with multiple return statements with subtype relation between returns
class Base { private m; }
class Derived extends Base { private q; }
@@ -119,5 +123,34 @@ function f6(): number {
return;
}
class Derived2 extends Base { private r: string; }
class AnotherClass { private x }
// if f is a contextually typed function expression, the inferred return type is the union type
// of the types of the return statement expressions in the function body,
// ignoring return statements with no expressions.
var f7: (x: number) => string | number = x => { // should be (x: number) => number | string
if (x < 0) { return x; }
return x.toString();
}
var f8: (x: number) => any = x => { // should be (x: number) => Base
return new Base();
return new Derived2();
}
var f9: (x: number) => any = x => { // should be (x: number) => Base
return new Base();
return new Derived();
return new Derived2();
}
var f10: (x: number) => any = x => { // should be (x: number) => Derived | Derived1
return new Derived();
return new Derived2();
}
var f11: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
return new Base();
return new AnotherClass();
}
var f12: (x: number) => any = x => { // should be (x: number) => Base | AnotherClass
return new Base();
return; // should be ignored
return new AnotherClass();
}