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tests/cases/compiler/narrowingMutualSubtypes.ts(117,17): error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'any[] | Record<string, any>'.
No index signature with a parameter of type 'string' was found on type 'any[] | Record<string, any>'.
tests/cases/compiler/narrowingMutualSubtypes.ts(118,29): error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'any[] | Record<string, any>'.
No index signature with a parameter of type 'string' was found on type 'any[] | Record<string, any>'.
==== tests/cases/compiler/narrowingMutualSubtypes.ts (2 errors) ====
// Check that `any` is a strict supertype of `unknown`
declare const ru1: { [x: string]: unknown };
declare const ra1: { [x: string]: any };
const a1a = [ru1, ra1]; // { [x: string]: any }[]
const a1b = [ra1, ru1]; // { [x: string]: any }[]
declare const ra2: { [x: string]: any };
declare const ru2: { [x: string]: unknown };
const a2a = [ru2, ra2]; // { [x: string]: any }[]
const a2b = [ra2, ru2]; // { [x: string]: any }[]
// Check that `{}` is strict supertype of any non-empty object
const c3 = {};
declare const r3: { [x: string]: unknown }
const a3a = [c3, r3]; // {}[]
const a3b = [r3, c3]; // {}[]
declare const r4: { [x: string]: unknown }
const c4 = {};
const a4a = [c4, r4]; // {}[]
const a4b = [r4, c4]; // {}[]
// Check that {} is a strict supertype of Record<string, unknown>
declare function isObject1(value: unknown): value is Record<string, unknown>;
function gg1(x: {}) {
if (isObject1(x)) {
x; // Record<string, unknown>
}
else {
x; // {}
}
x; // {}
}
declare function isObject2(value: unknown): value is {};
function gg2(x: Record<string, unknown>) {
if (isObject2(x)) {
x; // Record<string, unknown>
}
else {
x; // never
}
x; // Record<string, unknown>
}
// Check that {} is a strict supertype of Record<string, any>
declare function isObject3(value: unknown): value is Record<string, any>;
function gg3(x: {}) {
if (isObject3(x)) {
x; // Record<string, any>
}
else {
x; // {}
}
x; // {}
}
declare function isObject4(value: unknown): value is {};
function gg4(x: Record<string, any>) {
if (isObject4(x)) {
x; // Record<string, any>
}
else {
x; // never
}
x; // Record<string, any>
}
// Repro from #50916
type Identity<T> = {[K in keyof T]: T[K]};
type Self<T> = T extends unknown ? Identity<T> : never;
function is<T>(value: T): value is Self<T> {
return true;
}
type Union = {a: number} | {b: number} | {c: number};
function example(x: Union) {
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
if (is(x)) {}
x; // Union
}
function checksArrayOrObject1(obj: Record<string, any> | Record<string, any>[]) {
// "accidentally" guards the first branch on the length
if (Array.isArray(obj) && obj.length) {
for (let key in obj) {
if (obj[key] !== undefined) {
console.log(obj[key])
}
}
}
else {
// 'obj' should probably not include an array type here.
for (let key in obj) {
if (obj[key] !== undefined) {
~~~~~~~~
!!! error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'any[] | Record<string, any>'.
!!! error TS7053: No index signature with a parameter of type 'string' was found on type 'any[] | Record<string, any>'.
console.log(obj[key])
~~~~~~~~
!!! error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'any[] | Record<string, any>'.
!!! error TS7053: No index signature with a parameter of type 'string' was found on type 'any[] | Record<string, any>'.
}
}
}
}
function checksArrayOrObject2(obj: Record<string, any> | Record<string, any>[]) {
if (Array.isArray(obj)) {
// obj should only be an array type here
for (let key in obj) {
if (obj[key] !== undefined) {
console.log(obj[key])
}
}
}
else {
// 'obj' should probably not include an array type here.
for (let key in obj) {
if (obj[key] !== undefined) {
console.log(obj[key])
}
}
}
}
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