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Merged
Anders Hejlsberg (ahejlsberg) merged 4 commits into from
Mar 26, 2021
Merged

Template literal types for contextually typed template literal expressions #43376

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df77f4d
Template literal types for contextually typed template literal expres…
ahejlsberg Mar 25, 2021
1ba291c
Accept new baselines
ahejlsberg Mar 25, 2021
c8ce5c6
Add regression test
ahejlsberg Mar 25, 2021
a155082
Add a few more tests
ahejlsberg Mar 26, 2021
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Add a few more tests
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@ahejlsberg
ahejlsberg committed Mar 26, 2021
commit a1550821ab817a1e078996a26b52de26ef6078f4
8 changes: 8 additions & 0 deletions tests/baselines/reference/templateLiteralTypes2.errors.txt
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Expand Up @@ -94,6 +94,14 @@ tests/cases/conformance/types/literal/templateLiteralTypes2.ts(70,9): error TS23
!!! error TS2322: Type '`foo${number}`' is not assignable to type '{ length: number; }'.
}

declare function g1<T>(x: T): T;
declare function g2<T extends string>(x: T): T;

function ft20(s: string) {
let x1 = g1(`xyz-${s}`); // string
let x2 = g2(`xyz-${s}`); // `xyz-${string}`
}

// Repro from #41631

declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
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15 changes: 15 additions & 0 deletions tests/baselines/reference/templateLiteralTypes2.js
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Expand Up @@ -71,6 +71,14 @@ function ft14(t: `foo${number}`) {
let x6: { length: number } = t;
}

declare function g1<T>(x: T): T;
declare function g2<T extends string>(x: T): T;

function ft20(s: string) {
let x1 = g1(`xyz-${s}`); // string
let x2 = g2(`xyz-${s}`); // `xyz-${string}`
}

// Repro from #41631

declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
Expand Down Expand Up @@ -167,6 +175,10 @@ function ft14(t) {
var x4 = t;
var x6 = t;
}
function ft20(s) {
var x1 = g1("xyz-" + s); // string
var x2 = g2("xyz-" + s); // `xyz-${string}`
}
var t1 = takesLiteral("foo.bar.baz"); // "baz"
var id2 = "foo.bar.baz";
var t2 = takesLiteral(id2); // "baz"
Expand Down Expand Up @@ -195,6 +207,9 @@ declare function nonWidening<T extends string | number | symbol>(x: T): T;
declare function ft13(s: string, cond: boolean): void;
declare type T0 = string | `${number}px`;
declare function ft14(t: `foo${number}`): void;
declare function g1<T>(x: T): T;
declare function g2<T extends string>(x: T): T;
declare function ft20(s: string): void;
declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
declare const t1: "baz";
declare const id2 = "foo.bar.baz";
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101 changes: 65 additions & 36 deletions tests/baselines/reference/templateLiteralTypes2.symbols
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Expand Up @@ -257,78 +257,107 @@ function ft14(t: `foo${number}`) {
>t : Symbol(t, Decl(templateLiteralTypes2.ts, 64, 14))
}

declare function g1<T>(x: T): T;
>g1 : Symbol(g1, Decl(templateLiteralTypes2.ts, 70, 1))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 72, 20))
>x : Symbol(x, Decl(templateLiteralTypes2.ts, 72, 23))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 72, 20))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 72, 20))

declare function g2<T extends string>(x: T): T;
>g2 : Symbol(g2, Decl(templateLiteralTypes2.ts, 72, 32))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 73, 20))
>x : Symbol(x, Decl(templateLiteralTypes2.ts, 73, 38))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 73, 20))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 73, 20))

function ft20(s: string) {
>ft20 : Symbol(ft20, Decl(templateLiteralTypes2.ts, 73, 47))
>s : Symbol(s, Decl(templateLiteralTypes2.ts, 75, 14))

let x1 = g1(`xyz-${s}`); // string
>x1 : Symbol(x1, Decl(templateLiteralTypes2.ts, 76, 7))
>g1 : Symbol(g1, Decl(templateLiteralTypes2.ts, 70, 1))
>s : Symbol(s, Decl(templateLiteralTypes2.ts, 75, 14))

let x2 = g2(`xyz-${s}`); // `xyz-${string}`
>x2 : Symbol(x2, Decl(templateLiteralTypes2.ts, 77, 7))
>g2 : Symbol(g2, Decl(templateLiteralTypes2.ts, 72, 32))
>s : Symbol(s, Decl(templateLiteralTypes2.ts, 75, 14))
}

// Repro from #41631

declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 74, 30))
>literal : Symbol(literal, Decl(templateLiteralTypes2.ts, 74, 48))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 74, 30))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 74, 30))
>R : Symbol(R, Decl(templateLiteralTypes2.ts, 74, 87))
>R : Symbol(R, Decl(templateLiteralTypes2.ts, 74, 87))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 82, 30))
>literal : Symbol(literal, Decl(templateLiteralTypes2.ts, 82, 48))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 82, 30))
>T : Symbol(T, Decl(templateLiteralTypes2.ts, 82, 30))
>R : Symbol(R, Decl(templateLiteralTypes2.ts, 82, 87))
>R : Symbol(R, Decl(templateLiteralTypes2.ts, 82, 87))

const t1 = takesLiteral("foo.bar.baz"); // "baz"
>t1 : Symbol(t1, Decl(templateLiteralTypes2.ts, 76, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>t1 : Symbol(t1, Decl(templateLiteralTypes2.ts, 84, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))

const id2 = "foo.bar.baz";
>id2 : Symbol(id2, Decl(templateLiteralTypes2.ts, 77, 5))
>id2 : Symbol(id2, Decl(templateLiteralTypes2.ts, 85, 5))

const t2 = takesLiteral(id2); // "baz"
>t2 : Symbol(t2, Decl(templateLiteralTypes2.ts, 78, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>id2 : Symbol(id2, Decl(templateLiteralTypes2.ts, 77, 5))
>t2 : Symbol(t2, Decl(templateLiteralTypes2.ts, 86, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))
>id2 : Symbol(id2, Decl(templateLiteralTypes2.ts, 85, 5))

declare const someString: string;
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 80, 13))
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 88, 13))

const t3 = takesLiteral(`foo.bar.${someString}`); // string
>t3 : Symbol(t3, Decl(templateLiteralTypes2.ts, 81, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 80, 13))
>t3 : Symbol(t3, Decl(templateLiteralTypes2.ts, 89, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 88, 13))

const id4 = `foo.bar.${someString}`;
>id4 : Symbol(id4, Decl(templateLiteralTypes2.ts, 83, 5))
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 80, 13))
>id4 : Symbol(id4, Decl(templateLiteralTypes2.ts, 91, 5))
>someString : Symbol(someString, Decl(templateLiteralTypes2.ts, 88, 13))

const t4 = takesLiteral(id4); // string
>t4 : Symbol(t4, Decl(templateLiteralTypes2.ts, 84, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>id4 : Symbol(id4, Decl(templateLiteralTypes2.ts, 83, 5))
>t4 : Symbol(t4, Decl(templateLiteralTypes2.ts, 92, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))
>id4 : Symbol(id4, Decl(templateLiteralTypes2.ts, 91, 5))

declare const someUnion: 'abc' | 'def' | 'ghi';
>someUnion : Symbol(someUnion, Decl(templateLiteralTypes2.ts, 86, 13))
>someUnion : Symbol(someUnion, Decl(templateLiteralTypes2.ts, 94, 13))

const t5 = takesLiteral(`foo.bar.${someUnion}`); // "abc" | "def" | "ghi"
>t5 : Symbol(t5, Decl(templateLiteralTypes2.ts, 87, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 70, 1))
>someUnion : Symbol(someUnion, Decl(templateLiteralTypes2.ts, 86, 13))
>t5 : Symbol(t5, Decl(templateLiteralTypes2.ts, 95, 5))
>takesLiteral : Symbol(takesLiteral, Decl(templateLiteralTypes2.ts, 78, 1))
>someUnion : Symbol(someUnion, Decl(templateLiteralTypes2.ts, 94, 13))

// Repro from #41732

const pixelValue: number = 22;
>pixelValue : Symbol(pixelValue, Decl(templateLiteralTypes2.ts, 91, 5))
>pixelValue : Symbol(pixelValue, Decl(templateLiteralTypes2.ts, 99, 5))

type PixelValueType = `${number}px`;
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 91, 30))
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 99, 30))

const pixelString: PixelValueType = `22px`;
>pixelString : Symbol(pixelString, Decl(templateLiteralTypes2.ts, 95, 5))
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 91, 30))
>pixelString : Symbol(pixelString, Decl(templateLiteralTypes2.ts, 103, 5))
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 99, 30))

const pixelStringWithTemplate: PixelValueType = `${pixelValue}px`;
>pixelStringWithTemplate : Symbol(pixelStringWithTemplate, Decl(templateLiteralTypes2.ts, 97, 5))
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 91, 30))
>pixelValue : Symbol(pixelValue, Decl(templateLiteralTypes2.ts, 91, 5))
>pixelStringWithTemplate : Symbol(pixelStringWithTemplate, Decl(templateLiteralTypes2.ts, 105, 5))
>PixelValueType : Symbol(PixelValueType, Decl(templateLiteralTypes2.ts, 99, 30))
>pixelValue : Symbol(pixelValue, Decl(templateLiteralTypes2.ts, 99, 5))

// Repro from #43143

function getCardTitle(title: string): `test-${string}` {
>getCardTitle : Symbol(getCardTitle, Decl(templateLiteralTypes2.ts, 97, 66))
>title : Symbol(title, Decl(templateLiteralTypes2.ts, 101, 22))
>getCardTitle : Symbol(getCardTitle, Decl(templateLiteralTypes2.ts, 105, 66))
>title : Symbol(title, Decl(templateLiteralTypes2.ts, 109, 22))

return `test-${title}`;
>title : Symbol(title, Decl(templateLiteralTypes2.ts, 101, 22))
>title : Symbol(title, Decl(templateLiteralTypes2.ts, 109, 22))
}

27 changes: 27 additions & 0 deletions tests/baselines/reference/templateLiteralTypes2.types
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Expand Up @@ -283,6 +283,33 @@ function ft14(t: `foo${number}`) {
>t : `foo${number}`
}

declare function g1<T>(x: T): T;
>g1 : <T>(x: T) => T
>x : T

declare function g2<T extends string>(x: T): T;
>g2 : <T extends string>(x: T) => T
>x : T

function ft20(s: string) {
>ft20 : (s: string) => void
>s : string

let x1 = g1(`xyz-${s}`); // string
>x1 : string
>g1(`xyz-${s}`) : string
>g1 : <T>(x: T) => T
>`xyz-${s}` : string
>s : string

let x2 = g2(`xyz-${s}`); // `xyz-${string}`
>x2 : `xyz-${string}`
>g2(`xyz-${s}`) : `xyz-${string}`
>g2 : <T extends string>(x: T) => T
>`xyz-${s}` : `xyz-${string}`
>s : string
}

// Repro from #41631

declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
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8 changes: 8 additions & 0 deletions tests/cases/conformance/types/literal/templateLiteralTypes2.ts
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Expand Up @@ -73,6 +73,14 @@ function ft14(t: `foo${number}`) {
let x6: { length: number } = t;
}

declare function g1<T>(x: T): T;
declare function g2<T extends string>(x: T): T;

function ft20(s: string) {
let x1 = g1(`xyz-${s}`); // string
let x2 = g2(`xyz-${s}`); // `xyz-${string}`
}

// Repro from #41631

declare function takesLiteral<T extends string>(literal: T): T extends `foo.bar.${infer R}` ? R : unknown;
Expand Down