Skip to content

Properly reduce intersections of string literal and template literal types#41162

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Anders Hejlsberg (ahejlsberg) merged 3 commits into from
Oct 19, 2020
Merged

Properly reduce intersections of string literal and template literal types #41162

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
391f3b5
Properly reduce single element intersections
ahejlsberg Oct 19, 2020
400428b
Add regression test
ahejlsberg Oct 19, 2020
d8a2f97
Accept new baselines
ahejlsberg Oct 19, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 4 additions & 6 deletions src/compiler/checker.ts
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -13373,6 +13373,9 @@ namespace ts {
includes & TypeFlags.VoidLike && includes & (TypeFlags.DisjointDomains & ~TypeFlags.VoidLike)) {
return neverType;
}
if (includes & TypeFlags.TemplateLiteral && includes & TypeFlags.StringLiteral && extractRedundantTemplateLiterals(typeSet)) {
return neverType;
}
if (includes & TypeFlags.Any) {
return includes & TypeFlags.IncludesWildcard ? wildcardType : anyType;
}
Expand DownExpand Up@@ -13424,12 +13427,7 @@ namespace ts {
}
}
else {
if (includes & TypeFlags.TemplateLiteral && includes & TypeFlags.StringLiteral && extractRedundantTemplateLiterals(typeSet)) {
result = neverType;
}
else {
result = createIntersectionType(typeSet, aliasSymbol, aliasTypeArguments);
}
result = createIntersectionType(typeSet, aliasSymbol, aliasTypeArguments);
}
intersectionTypes.set(id, result);
}
Expand Down
8 changes: 7 additions & 1 deletion tests/baselines/reference/templateLiteralTypesPatterns.errors.txt
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -332,4 +332,10 @@ tests/cases/conformance/types/literal/templateLiteralTypesPatterns.ts(160,7): er
const exampleBad: B = "anything"; // fails
~~~~~~~~~~
!!! error TS2322: Type '"anything"' is not assignable to type '`${number} ${number}`'.
const exampleGood: B = "1 2"; // ok
const exampleGood: B = "1 2"; // ok

// Repro from #41161

var aa: '0';
var aa: '0' & `${number}`;

11 changes: 10 additions & 1 deletion tests/baselines/reference/templateLiteralTypesPatterns.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -159,7 +159,13 @@ const shouldWork2: AGen<string> = null as any as AGen<number>;
type A = `${number}`;
type B = `${A} ${A}`;
const exampleBad: B = "anything"; // fails
const exampleGood: B = "1 2"; // ok
const exampleGood: B = "1 2"; // ok

// Repro from #41161

var aa: '0';
var aa: '0' & `${number}`;


//// [templateLiteralTypesPatterns.js]
"use strict";
Expand DownExpand Up@@ -280,3 +286,6 @@ var shouldWork1 = null;
var shouldWork2 = null;
var exampleBad = "anything"; // fails
var exampleGood = "1 2"; // ok
// Repro from #41161
var aa;
var aa;
8 changes: 8 additions & 0 deletions tests/baselines/reference/templateLiteralTypesPatterns.symbols
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -393,3 +393,11 @@ const exampleGood: B = "1 2"; // ok
>exampleGood : Symbol(exampleGood, Decl(templateLiteralTypesPatterns.ts, 160, 5))
>B : Symbol(B, Decl(templateLiteralTypesPatterns.ts, 157, 21))

// Repro from #41161

var aa: '0';
>aa : Symbol(aa, Decl(templateLiteralTypesPatterns.ts, 164, 3), Decl(templateLiteralTypesPatterns.ts, 165, 3))

var aa: '0' & `${number}`;
>aa : Symbol(aa, Decl(templateLiteralTypesPatterns.ts, 164, 3), Decl(templateLiteralTypesPatterns.ts, 165, 3))

8 changes: 8 additions & 0 deletions tests/baselines/reference/templateLiteralTypesPatterns.types
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -552,3 +552,11 @@ const exampleGood: B = "1 2"; // ok
>exampleGood : `${number} ${number}`
>"1 2" : "1 2"

// Repro from #41161

var aa: '0';
>aa : "0"

var aa: '0' & `${number}`;
>aa : "0"

7 changes: 6 additions & 1 deletion tests/cases/conformance/types/literal/templateLiteralTypesPatterns.ts
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -159,4 +159,9 @@ const shouldWork2: AGen<string> = null as any as AGen<number>;
type A = `${number}`;
type B = `${A} ${A}`;
const exampleBad: B = "anything"; // fails
const exampleGood: B = "1 2"; // ok
const exampleGood: B = "1 2"; // ok

// Repro from #41161

var aa: '0';
var aa: '0' & `${number}`;