/
unknownControlFlow.js
846 lines (786 loc) · 18.1 KB
/
unknownControlFlow.js
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//// [unknownControlFlow.ts]
type T01 = {} & string; // string
type T02 = {} & 'a'; // 'a'
type T03 = {} & object; // object
type T04 = {} & { x: number }; // { x: number }
type T05 = {} & null; // never
type T06 = {} & undefined; // never
type T07 = undefined & void; // undefined
type T10 = string & {}; // Specially preserved
type T11 = number & {}; // Specially preserved
type T12 = bigint & {}; // Specially preserved
type ThisNode = {};
type ThatNode = {};
type ThisOrThatNode = ThisNode | ThatNode;
function f01(u: unknown) {
let x1: {} = u; // Error
let x2: {} | null | undefined = u;
let x3: {} | { x: string } | null | undefined = u;
let x4: ThisOrThatNode | null | undefined = u;
}
function f10(x: unknown) {
if (x) {
x; // {}
}
else {
x; // unknown
}
if (!x) {
x; // unknown
}
else {
x; // {}
}
}
function f11<T>(x: T) {
if (x) {
x; // T & {}
}
else {
x; // T
}
if (!x) {
x; // T
}
else {
x; // T & {}
}
}
function f12<T extends {}>(x: T) {
if (x) {
x; // T
}
else {
x; // T
}
}
function f20(x: unknown) {
if (x !== undefined) {
x; // {} | null
}
else {
x; // undefined
}
if (x !== null) {
x; // {} | undefined
}
else {
x; // null
}
if (x !== undefined && x !== null) {
x; // {}
}
else {
x; // null | undefined
}
if (x != undefined) {
x; // {}
}
else {
x; // null | undefined
}
if (x != null) {
x; // {}
}
else {
x; // null | undefined
}
}
function f21<T>(x: T) {
if (x !== undefined) {
x; // T & ({} | null)
}
else {
x; // T
}
if (x !== null) {
x; // T & ({} | undefined)
}
else {
x; // T
}
if (x !== undefined && x !== null) {
x; // T & {}
}
else {
x; // T
}
if (x != undefined) {
x; // T & {}
}
else {
x; // T
}
if (x != null) {
x; // T & {}
}
else {
x; // T
}
}
function f22<T extends {} | undefined>(x: T) {
if (x !== undefined) {
x; // T & {}
}
else {
x; // T
}
if (x !== null) {
x; // T
}
else {
x; // T
}
if (x !== undefined && x !== null) {
x; // T & {}
}
else {
x; // T
}
if (x != undefined) {
x; // T & {}
}
else {
x; // T
}
if (x != null) {
x; // T & {}
}
else {
x; // T
}
}
function f23<T>(x: T | undefined | null) {
if (x !== undefined) {
x; // T & {} | null
}
if (x !== null) {
x; // T & {} | undefined
}
if (x != undefined) {
x; // T & {}
}
if (x != null) {
x; // T & {}
}
}
function f30(x: {}) {
if (typeof x === "object") {
x; // object
}
}
function f31<T>(x: T) {
if (typeof x === "object") {
x; // T & object | T & null
}
if (x && typeof x === "object") {
x; // T & object
}
if (typeof x === "object" && x) {
x; // T & object
}
}
function f32<T extends {} | undefined>(x: T) {
if (typeof x === "object") {
x; // T & object
}
}
function possiblyNull<T>(x: T) {
return !!true ? x : null; // T | null
}
function possiblyUndefined<T>(x: T) {
return !!true ? x : undefined; // T | undefined
}
function possiblyNullOrUndefined<T>(x: T) {
return possiblyUndefined(possiblyNull(x)); // T | null | undefined
}
function ensureNotNull<T>(x: T) {
if (x === null) throw Error();
return x; // T & ({} | undefined)
}
function ensureNotUndefined<T>(x: T) {
if (x === undefined) throw Error();
return x; // T & ({} | null)
}
function ensureNotNullOrUndefined<T>(x: T) {
return ensureNotUndefined(ensureNotNull(x)); // T & {}
}
function f40(a: string | undefined, b: number | null | undefined) {
let a1 = ensureNotNullOrUndefined(a); // string
let b1 = ensureNotNullOrUndefined(b); // number
}
type QQ<T> = NonNullable<NonNullable<NonNullable<T>>>;
function f41<T>(a: T) {
let a1 = ensureNotUndefined(ensureNotNull(a)); // T & {}
let a2 = ensureNotNull(ensureNotUndefined(a)); // T & {}
let a3 = ensureNotNull(ensureNotNull(a)); // T & {} | T & undefined
let a4 = ensureNotUndefined(ensureNotUndefined(a)); // T & {} | T & null
let a5 = ensureNotNullOrUndefined(ensureNotNullOrUndefined(a)); // T & {}
let a6 = ensureNotNull(possiblyNullOrUndefined(a)); // T & {} | undefined
let a7 = ensureNotUndefined(possiblyNullOrUndefined(a)); // T & {} | null
let a8 = ensureNotNull(possiblyUndefined(a)); // T & {} | undefined
let a9 = ensureNotUndefined(possiblyNull(a)); // T & {} | null
}
// Repro from #48468
function deepEquals<T>(a: T, b: T): boolean {
if (typeof a !== 'object' || typeof b !== 'object' || !a || !b) {
return false;
}
if (Array.isArray(a) || Array.isArray(b)) {
return false;
}
if (Object.keys(a).length !== Object.keys(b).length) { // Error here
return false;
}
return true;
}
// Repro from #49386
function foo<T>(x: T | null) {
let y = x;
if (y !== null) {
y;
}
}
// We allow an unconstrained object of a generic type `T` to be indexed by a key of type `keyof T`
// without a check that the object is non-undefined and non-null. This is safe because `keyof T`
// is `never` (meaning no possible keys) for any `T` that includes `undefined` or `null`.
function ff1<T>(t: T, k: keyof T) {
t[k];
}
function ff2<T>(t: T & {}, k: keyof T) {
t[k];
}
function ff3<T>(t: T, k: keyof (T & {})) {
t[k]; // Error
}
function ff4<T>(t: T & {}, k: keyof (T & {})) {
t[k];
}
ff1(null, 'foo'); // Error
ff2(null, 'foo'); // Error
ff3(null, 'foo');
ff4(null, 'foo'); // Error
// Repro from #49681
type Foo = { [key: string]: unknown };
type NullableFoo = Foo | undefined;
type Bar<T extends NullableFoo> = NonNullable<T>[string];
// Generics and intersections with {}
function fx0<T>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx1<T extends unknown>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx2<T extends {}>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx3<T extends {} | undefined>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx4<T extends {} | null>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx5<T extends {} | null | undefined>(value: T & ({} | null)) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
// Double-equals narrowing
function fx10(x: string | number, y: number) {
if (x == y) {
x; // string | number
}
else {
x; // string | number
}
if (x != y) {
x; // string | number
}
else {
x; // string | number
}
}
// Repros from #50706
function SendBlob(encoding: unknown) {
if (encoding !== undefined && encoding !== 'utf8') {
throw new Error('encoding');
}
encoding;
};
function doSomething1<T extends unknown>(value: T): T {
if (value === undefined) {
return value;
}
if (value === 42) {
throw Error('Meaning of life value');
}
return value;
}
function doSomething2(value: unknown): void {
if (value === undefined) {
return;
}
if (value === 42) {
value;
}
}
// Repro from #51009
type TypeA = {
A: 'A',
B: 'B',
}
type TypeB = {
A: 'A',
B: 'B',
C: 'C',
}
type R<T extends keyof TypeA> =
T extends keyof TypeB ? [TypeA[T], TypeB[T]] : never;
type R2<T extends PropertyKey> =
T extends keyof TypeA ? T extends keyof TypeB ? [TypeA[T], TypeB[T]] : never : never;
// Repro from #51041
type AB = "A" | "B";
function x<T_AB extends AB>(x: T_AB & undefined, y: any) {
let r2: never = y as T_AB & undefined;
}
//// [unknownControlFlow.js]
"use strict";
function f01(u) {
var x1 = u; // Error
var x2 = u;
var x3 = u;
var x4 = u;
}
function f10(x) {
if (x) {
x; // {}
}
else {
x; // unknown
}
if (!x) {
x; // unknown
}
else {
x; // {}
}
}
function f11(x) {
if (x) {
x; // T & {}
}
else {
x; // T
}
if (!x) {
x; // T
}
else {
x; // T & {}
}
}
function f12(x) {
if (x) {
x; // T
}
else {
x; // T
}
}
function f20(x) {
if (x !== undefined) {
x; // {} | null
}
else {
x; // undefined
}
if (x !== null) {
x; // {} | undefined
}
else {
x; // null
}
if (x !== undefined && x !== null) {
x; // {}
}
else {
x; // null | undefined
}
if (x != undefined) {
x; // {}
}
else {
x; // null | undefined
}
if (x != null) {
x; // {}
}
else {
x; // null | undefined
}
}
function f21(x) {
if (x !== undefined) {
x; // T & ({} | null)
}
else {
x; // T
}
if (x !== null) {
x; // T & ({} | undefined)
}
else {
x; // T
}
if (x !== undefined && x !== null) {
x; // T & {}
}
else {
x; // T
}
if (x != undefined) {
x; // T & {}
}
else {
x; // T
}
if (x != null) {
x; // T & {}
}
else {
x; // T
}
}
function f22(x) {
if (x !== undefined) {
x; // T & {}
}
else {
x; // T
}
if (x !== null) {
x; // T
}
else {
x; // T
}
if (x !== undefined && x !== null) {
x; // T & {}
}
else {
x; // T
}
if (x != undefined) {
x; // T & {}
}
else {
x; // T
}
if (x != null) {
x; // T & {}
}
else {
x; // T
}
}
function f23(x) {
if (x !== undefined) {
x; // T & {} | null
}
if (x !== null) {
x; // T & {} | undefined
}
if (x != undefined) {
x; // T & {}
}
if (x != null) {
x; // T & {}
}
}
function f30(x) {
if (typeof x === "object") {
x; // object
}
}
function f31(x) {
if (typeof x === "object") {
x; // T & object | T & null
}
if (x && typeof x === "object") {
x; // T & object
}
if (typeof x === "object" && x) {
x; // T & object
}
}
function f32(x) {
if (typeof x === "object") {
x; // T & object
}
}
function possiblyNull(x) {
return !!true ? x : null; // T | null
}
function possiblyUndefined(x) {
return !!true ? x : undefined; // T | undefined
}
function possiblyNullOrUndefined(x) {
return possiblyUndefined(possiblyNull(x)); // T | null | undefined
}
function ensureNotNull(x) {
if (x === null)
throw Error();
return x; // T & ({} | undefined)
}
function ensureNotUndefined(x) {
if (x === undefined)
throw Error();
return x; // T & ({} | null)
}
function ensureNotNullOrUndefined(x) {
return ensureNotUndefined(ensureNotNull(x)); // T & {}
}
function f40(a, b) {
var a1 = ensureNotNullOrUndefined(a); // string
var b1 = ensureNotNullOrUndefined(b); // number
}
function f41(a) {
var a1 = ensureNotUndefined(ensureNotNull(a)); // T & {}
var a2 = ensureNotNull(ensureNotUndefined(a)); // T & {}
var a3 = ensureNotNull(ensureNotNull(a)); // T & {} | T & undefined
var a4 = ensureNotUndefined(ensureNotUndefined(a)); // T & {} | T & null
var a5 = ensureNotNullOrUndefined(ensureNotNullOrUndefined(a)); // T & {}
var a6 = ensureNotNull(possiblyNullOrUndefined(a)); // T & {} | undefined
var a7 = ensureNotUndefined(possiblyNullOrUndefined(a)); // T & {} | null
var a8 = ensureNotNull(possiblyUndefined(a)); // T & {} | undefined
var a9 = ensureNotUndefined(possiblyNull(a)); // T & {} | null
}
// Repro from #48468
function deepEquals(a, b) {
if (typeof a !== 'object' || typeof b !== 'object' || !a || !b) {
return false;
}
if (Array.isArray(a) || Array.isArray(b)) {
return false;
}
if (Object.keys(a).length !== Object.keys(b).length) { // Error here
return false;
}
return true;
}
// Repro from #49386
function foo(x) {
var y = x;
if (y !== null) {
y;
}
}
// We allow an unconstrained object of a generic type `T` to be indexed by a key of type `keyof T`
// without a check that the object is non-undefined and non-null. This is safe because `keyof T`
// is `never` (meaning no possible keys) for any `T` that includes `undefined` or `null`.
function ff1(t, k) {
t[k];
}
function ff2(t, k) {
t[k];
}
function ff3(t, k) {
t[k]; // Error
}
function ff4(t, k) {
t[k];
}
ff1(null, 'foo'); // Error
ff2(null, 'foo'); // Error
ff3(null, 'foo');
ff4(null, 'foo'); // Error
// Generics and intersections with {}
function fx0(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx1(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx2(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx3(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx4(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
function fx5(value) {
if (value === 42) {
value; // T & {}
}
else {
value; // T & ({} | null)
}
}
// Double-equals narrowing
function fx10(x, y) {
if (x == y) {
x; // string | number
}
else {
x; // string | number
}
if (x != y) {
x; // string | number
}
else {
x; // string | number
}
}
// Repros from #50706
function SendBlob(encoding) {
if (encoding !== undefined && encoding !== 'utf8') {
throw new Error('encoding');
}
encoding;
}
;
function doSomething1(value) {
if (value === undefined) {
return value;
}
if (value === 42) {
throw Error('Meaning of life value');
}
return value;
}
function doSomething2(value) {
if (value === undefined) {
return;
}
if (value === 42) {
value;
}
}
function x(x, y) {
var r2 = y;
}
//// [unknownControlFlow.d.ts]
type T01 = {} & string;
type T02 = {} & 'a';
type T03 = {} & object;
type T04 = {} & {
x: number;
};
type T05 = {} & null;
type T06 = {} & undefined;
type T07 = undefined & void;
type T10 = string & {};
type T11 = number & {};
type T12 = bigint & {};
type ThisNode = {};
type ThatNode = {};
type ThisOrThatNode = ThisNode | ThatNode;
declare function f01(u: unknown): void;
declare function f10(x: unknown): void;
declare function f11<T>(x: T): void;
declare function f12<T extends {}>(x: T): void;
declare function f20(x: unknown): void;
declare function f21<T>(x: T): void;
declare function f22<T extends {} | undefined>(x: T): void;
declare function f23<T>(x: T | undefined | null): void;
declare function f30(x: {}): void;
declare function f31<T>(x: T): void;
declare function f32<T extends {} | undefined>(x: T): void;
declare function possiblyNull<T>(x: T): T | null;
declare function possiblyUndefined<T>(x: T): T | undefined;
declare function possiblyNullOrUndefined<T>(x: T): T | null | undefined;
declare function ensureNotNull<T>(x: T): T & ({} | undefined);
declare function ensureNotUndefined<T>(x: T): T & ({} | null);
declare function ensureNotNullOrUndefined<T>(x: T): T & {};
declare function f40(a: string | undefined, b: number | null | undefined): void;
type QQ<T> = NonNullable<NonNullable<NonNullable<T>>>;
declare function f41<T>(a: T): void;
declare function deepEquals<T>(a: T, b: T): boolean;
declare function foo<T>(x: T | null): void;
declare function ff1<T>(t: T, k: keyof T): void;
declare function ff2<T>(t: T & {}, k: keyof T): void;
declare function ff3<T>(t: T, k: keyof (T & {})): void;
declare function ff4<T>(t: T & {}, k: keyof (T & {})): void;
type Foo = {
[key: string]: unknown;
};
type NullableFoo = Foo | undefined;
type Bar<T extends NullableFoo> = NonNullable<T>[string];
declare function fx0<T>(value: T & ({} | null)): void;
declare function fx1<T extends unknown>(value: T & ({} | null)): void;
declare function fx2<T extends {}>(value: T & ({} | null)): void;
declare function fx3<T extends {} | undefined>(value: T & ({} | null)): void;
declare function fx4<T extends {} | null>(value: T & ({} | null)): void;
declare function fx5<T extends {} | null | undefined>(value: T & ({} | null)): void;
declare function fx10(x: string | number, y: number): void;
declare function SendBlob(encoding: unknown): void;
declare function doSomething1<T extends unknown>(value: T): T;
declare function doSomething2(value: unknown): void;
type TypeA = {
A: 'A';
B: 'B';
};
type TypeB = {
A: 'A';
B: 'B';
C: 'C';
};
type R<T extends keyof TypeA> = T extends keyof TypeB ? [TypeA[T], TypeB[T]] : never;
type R2<T extends PropertyKey> = T extends keyof TypeA ? T extends keyof TypeB ? [TypeA[T], TypeB[T]] : never : never;
type AB = "A" | "B";
declare function x<T_AB extends AB>(x: T_AB & undefined, y: any): void;