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tests/cases/conformance/types/literal/templateLiteralTypes3.ts(20,19): error TS2345: Argument of type '"hello"' is not assignable to parameter of type '`*${string}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(57,5): error TS2322: Type '"hello"' is not assignable to type '`*${string}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(69,5): error TS2322: Type '"123"' is not assignable to type '`*${number}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(71,5): error TS2322: Type '"**123**"' is not assignable to type '`*${number}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(72,5): error TS2322: Type '`*${string}*`' is not assignable to type '`*${number}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(74,5): error TS2322: Type '"*false*" | "*true*"' is not assignable to type '`*${number}*`'.
Type '"*false*"' is not assignable to type '`*${number}*`'.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(133,9): error TS2367: This comparison appears to be unintentional because the types '`foo-${string}`' and '`baz-${string}`' have no overlap.
tests/cases/conformance/types/literal/templateLiteralTypes3.ts(141,9): error TS2367: This comparison appears to be unintentional because the types '`foo-${T}`' and '`baz-${T}`' have no overlap.
==== tests/cases/conformance/types/literal/templateLiteralTypes3.ts (8 errors) ====
// Inference from template literal type to template literal type
type Foo1<T> = T extends `*${infer U}*` ? U : never;
type T01 = Foo1<'hello'>;
type T02 = Foo1<'*hello*'>;
type T03 = Foo1<'**hello**'>;
type T04 = Foo1<`*${string}*`>;
type T05 = Foo1<`*${number}*`>;
type T06 = Foo1<`*${bigint}*`>;
type T07 = Foo1<`*${any}*`>;
type T08 = Foo1<`**${string}**`>;
type T09 = Foo1<`**${string}**${string}**`>;
type T10 = Foo1<`**${'a' | 'b' | 'c'}**`>;
type T11 = Foo1<`**${boolean}**${boolean}**`>;
declare function foo1<V extends string>(arg: `*${V}*`): V;
function f1<T extends string>(s: string, n: number, b: boolean, t: T) {
let x1 = foo1('hello'); // Error
~~~~~~~
!!! error TS2345: Argument of type '"hello"' is not assignable to parameter of type '`*${string}*`'.
let x2 = foo1('*hello*');
let x3 = foo1('**hello**');
let x4 = foo1(`*${s}*` as const);
let x5 = foo1(`*${n}*` as const);
let x6 = foo1(`*${b}*` as const);
let x7 = foo1(`*${t}*` as const);
let x8 = foo1(`**${s}**` as const);
}
// Inference to a placeholder immediately followed by another placeholder infers a single
// character or placeholder from the source.
type Parts<T> =
T extends '' ? [] :
T extends `${infer Head}${infer Tail}` ? [Head, ...Parts<Tail>] :
never;
type T20 = Parts<`abc`>;
type T21 = Parts<`*${string}*`>;
type T22 = Parts<`*${number}*`>;
type T23 = Parts<`*${number}*${string}*${bigint}*`>;
function f2() {
let x: `${number}.${number}.${number}`;
x = '1.1.1';
x = '1.1.1' as `1.1.${number}`;
x = '1.1.1' as `1.${number}.1`;
x = '1.1.1' as `1.${number}.${number}`;
x = '1.1.1' as `${number}.1.1`;
x = '1.1.1' as `${number}.1.${number}`;
x = '1.1.1' as `${number}.${number}.1`;
x = '1.1.1' as `${number}.${number}.${number}`;
}
function f3<T extends string>(s: string, n: number, b: boolean, t: T) {
let x: `*${string}*`;
x = 'hello'; // Error
~
!!! error TS2322: Type '"hello"' is not assignable to type '`*${string}*`'.
x = '*hello*';
x = '**hello**';
x = `*${s}*` as const;
x = `*${n}*` as const;
x = `*${b}*` as const;
x = `*${t}*` as const;
x = `**${s}**` as const;
}
function f4<T extends number>(s: string, n: number, b: boolean, t: T) {
let x: `*${number}*`;
x = '123'; // Error
~
!!! error TS2322: Type '"123"' is not assignable to type '`*${number}*`'.
x = '*123*';
x = '**123**'; // Error
~
!!! error TS2322: Type '"**123**"' is not assignable to type '`*${number}*`'.
x = `*${s}*` as const; // Error
~
!!! error TS2322: Type '`*${string}*`' is not assignable to type '`*${number}*`'.
x = `*${n}*` as const;
x = `*${b}*` as const; // Error
~
!!! error TS2322: Type '"*false*" | "*true*"' is not assignable to type '`*${number}*`'.
!!! error TS2322: Type '"*false*"' is not assignable to type '`*${number}*`'.
x = `*${t}*` as const;
}
// Repro from #43060
type A<T> = T extends `${infer U}.${infer V}` ? U | V : never
type B = A<`test.1024`>; // "test" | "1024"
type C = A<`test.${number}`>; // "test" | `${number}`
type D<T> = T extends `${infer U}.${number}` ? U : never
type E = D<`test.1024`>; // "test"
type F = D<`test.${number}`>; // "test"
type G<T> = T extends `${infer U}.${infer V}` ? U | V : never
type H = G<`test.hoge`>; // "test" | "hoge"
type I = G<`test.${string}`>; // string ("test" | string reduces to string)
type J<T> = T extends `${infer U}.${string}` ? U : never
type K = J<`test.hoge`>; // "test"
type L = J<`test.${string}`>; // "test""
// Repro from #43243
type Templated = `${string} ${string}`;
const value1: string = "abc";
const templated1: Templated = `${value1} abc` as const;
// Type '`${string} abc`' is not assignable to type '`${string} ${string}`'.
const value2 = "abc";
const templated2: Templated = `${value2} abc` as const;
// Repro from #43620
type Prefixes = "foo" | "bar";
type AllPrefixData = "foo:baz" | "bar:baz";
type PrefixData<P extends Prefixes> = `${P}:baz`;
interface ITest<P extends Prefixes, E extends AllPrefixData = PrefixData<P>> {
blah: string;
}
// Repro from #45906
type Schema = { a: { b: { c: number } } };
declare function chain<F extends keyof Schema>(field: F | `${F}.${F}`): void;
chain("a");
// Repro from #46125
function ff1(x: `foo-${string}`, y: `${string}-bar`, z: `baz-${string}`) {
if (x === y) {
x; // `foo-${string}`
}
if (x === z) { // Error
~~~~~~~
!!! error TS2367: This comparison appears to be unintentional because the types '`foo-${string}`' and '`baz-${string}`' have no overlap.
}
}
function ff2<T extends string>(x: `foo-${T}`, y: `${T}-bar`, z: `baz-${T}`) {
if (x === y) {
x; // `foo-${T}`
}
if (x === z) { // Error
~~~~~~~
!!! error TS2367: This comparison appears to be unintentional because the types '`foo-${T}`' and '`baz-${T}`' have no overlap.
}
}
function ff3(x: string, y: `foo-${string}` | 'bar') {
if (x === y) {
x; // `foo-${string}` | 'bar'
}
}
function ff4(x: string, y: `foo-${string}`) {
if (x === 'foo-test') {
x; // 'foo-test'
}
if (y === 'foo-test') {
y; // 'foo-test'
}
}
// Repro from #46045
type Action =
| { type: `${string}_REQUEST` }
| { type: `${string}_SUCCESS`, response: string };
function reducer(action: Action) {
if (action.type === 'FOO_SUCCESS') {
action.type;
action.response;
}
}
// Repro from #46768
type DotString = `${string}.${string}.${string}`;
declare function noSpread<P extends DotString>(args: P[]): P;
declare function spread<P extends DotString>(...args: P[]): P;
noSpread([`1.${'2'}.3`, `1.${'2'}.4`]);
noSpread([`1.${'2' as string}.3`, `1.${'2' as string}.4`]);
spread(`1.${'2'}.3`, `1.${'2'}.4`);
spread(`1.${'2' as string}.3`, `1.${'2' as string}.4`);
function ft1<T extends string>(t: T, u: Uppercase<T>, u1: Uppercase<`1.${T}.3`>, u2: Uppercase<`1.${T}.4`>) {
spread(`1.${t}.3`, `1.${t}.4`);
spread(`1.${u}.3`, `1.${u}.4`);
spread(u1, u2);
}
// Repro from #52685
type Boom = 'abc' | 'def' | `a${string}` | Lowercase<string>;
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