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Add special inference rule for 'T | PromiseLike<T>' #60334

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787da6f
Add special inference rule for 'T | PromiseLike<T>'
rbuckton Oct 24, 2024
e28fd86
isAwaitedLikeType limited to two types in union
rbuckton Nov 1, 2024
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54 changes: 52 additions & 2 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -25992,6 +25992,42 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
return isTupleType(type) && getTupleElementType(type, 0) === getIndexedAccessType(typeParameter, getNumberLiteralType(0)) && !getTypeOfPropertyOfType(type, "1" as __String);
}

function isAwaitedLikeType(type: Type) {
if (type.flags & TypeFlags.Union) {
let typeVariable: Type | undefined;
let promisedType: Type | undefined;
const types = (type as UnionType).types;
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Should this inspect all constituents instead of eagerly returning when a match has been found?

if (types.length !== 2) {
return false;
}
for (const t of types) {
if (t.flags & TypeFlags.TypeVariable) {
if (typeVariable) {
return false;
}
typeVariable = t;
if (promisedType) {
return typeVariable === promisedType;
}
continue;
}
if (isPromiseType(t)) {
if (promisedType) {
return false;
}
[promisedType] = getTypeArguments(t as TypeReference);
if (typeVariable) {
return typeVariable === promisedType;
}
continue;
}
return false;
}
return true;
}
return false;
}

function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type, priority = InferencePriority.None, contravariant = false) {
let bivariant = false;
let propagationType: Type;
Expand All @@ -26016,6 +26052,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
propagationType = savePropagationType;
return;
}
// If the target is either `T | Promise<T>` or `T | PromiseLike<T>`, continue inferring types with the
// `AwaitedLikeType` priority.
if (!(priority & InferencePriority.AwaitedLikeType) && isAwaitedLikeType(target)) {
priority |= InferencePriority.AwaitedLikeType;
}
if (source.aliasSymbol && source.aliasSymbol === target.aliasSymbol) {
if (source.aliasTypeArguments) {
// Source and target are types originating in the same generic type alias declaration.
Expand Down Expand Up @@ -26165,7 +26206,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
}
if (
getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (
(source as TypeReference).target === (target as TypeReference).target || isArrayType(source) && isArrayType(target)
(source as TypeReference).target === (target as TypeReference).target ||
isArrayType(source) && isArrayType(target) ||
isPromiseType(source) && isPromiseType(target)
) &&
!((source as TypeReference).node && (target as TypeReference).node)
) {
Expand Down Expand Up @@ -26583,7 +26626,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
function inferFromObjectTypes(source: Type, target: Type) {
if (
getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (
(source as TypeReference).target === (target as TypeReference).target || isArrayType(source) && isArrayType(target)
(source as TypeReference).target === (target as TypeReference).target ||
isArrayType(source) && isArrayType(target) ||
isPromiseType(source) && isPromiseType(target)
)
) {
// If source and target are references to the same generic type, infer from type arguments
Expand Down Expand Up @@ -42488,6 +42533,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
}
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This array can probably be cached

}

function isPromiseType(type: Type) {
return isReferenceToType(type, getGlobalPromiseType(/*reportErrors*/ false)) ||
isReferenceToType(type, getGlobalPromiseLikeType(/*reportErrors*/ false));
}

function getAwaitedTypeOfPromise(type: Type, errorNode?: Node, diagnosticMessage?: DiagnosticMessage, ...args: DiagnosticArguments): Type | undefined {
const promisedType = getPromisedTypeOfPromise(type, errorNode);
return promisedType && getAwaitedType(promisedType, errorNode, diagnosticMessage, ...args);
Expand Down
27 changes: 14 additions & 13 deletions src/compiler/types.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -7027,19 +7027,20 @@ export type TypeMapper =
export const enum InferencePriority {
None = 0,
NakedTypeVariable = 1 << 0, // Naked type variable in union or intersection type
SpeculativeTuple = 1 << 1, // Speculative tuple inference
SubstituteSource = 1 << 2, // Source of inference originated within a substitution type's substitute
HomomorphicMappedType = 1 << 3, // Reverse inference for homomorphic mapped type
PartialHomomorphicMappedType = 1 << 4, // Partial reverse inference for homomorphic mapped type
MappedTypeConstraint = 1 << 5, // Reverse inference for mapped type
ContravariantConditional = 1 << 6, // Conditional type in contravariant position
ReturnType = 1 << 7, // Inference made from return type of generic function
LiteralKeyof = 1 << 8, // Inference made from a string literal to a keyof T
NoConstraints = 1 << 9, // Don't infer from constraints of instantiable types
AlwaysStrict = 1 << 10, // Always use strict rules for contravariant inferences
MaxValue = 1 << 11, // Seed for inference priority tracking

PriorityImpliesCombination = ReturnType | MappedTypeConstraint | LiteralKeyof, // These priorities imply that the resulting type should be a combination of all candidates
AwaitedLikeType = 1 << 1, // A type that is essentially awaited
SpeculativeTuple = 1 << 2, // Speculative tuple inference
SubstituteSource = 1 << 3, // Source of inference originated within a substitution type's substitute
HomomorphicMappedType = 1 << 4, // Reverse inference for homomorphic mapped type
PartialHomomorphicMappedType = 1 << 5, // Partial reverse inference for homomorphic mapped type
MappedTypeConstraint = 1 << 6, // Reverse inference for mapped type
ContravariantConditional = 1 << 7, // Conditional type in contravariant position
ReturnType = 1 << 8, // Inference made from return type of generic function
LiteralKeyof = 1 << 9, // Inference made from a string literal to a keyof T
NoConstraints = 1 << 10, // Don't infer from constraints of instantiable types
AlwaysStrict = 1 << 11, // Always use strict rules for contravariant inferences
MaxValue = 1 << 12, // Seed for inference priority tracking

PriorityImpliesCombination = ReturnType | AwaitedLikeType | MappedTypeConstraint | LiteralKeyof, // These priorities imply that the resulting type should be a combination of all candidates
Circularity = -1, // Inference circularity (value less than all other priorities)
}

Expand Down
25 changes: 13 additions & 12 deletions tests/baselines/reference/api/typescript.d.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -6861,18 +6861,19 @@ declare namespace ts {
enum InferencePriority {
None = 0,
NakedTypeVariable = 1,
SpeculativeTuple = 2,
SubstituteSource = 4,
HomomorphicMappedType = 8,
PartialHomomorphicMappedType = 16,
MappedTypeConstraint = 32,
ContravariantConditional = 64,
ReturnType = 128,
LiteralKeyof = 256,
NoConstraints = 512,
AlwaysStrict = 1024,
MaxValue = 2048,
PriorityImpliesCombination = 416,
AwaitedLikeType = 2,
SpeculativeTuple = 4,
SubstituteSource = 8,
HomomorphicMappedType = 16,
PartialHomomorphicMappedType = 32,
MappedTypeConstraint = 64,
ContravariantConditional = 128,
ReturnType = 256,
LiteralKeyof = 512,
NoConstraints = 1024,
AlwaysStrict = 2048,
MaxValue = 4096,
PriorityImpliesCombination = 834,
Circularity = -1,
}
interface FileExtensionInfo {
Expand Down
28 changes: 27 additions & 1 deletion tests/baselines/reference/promiseType.js
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
//// [promiseType.ts]
declare var p: Promise<boolean>;
declare var x: any;
declare var b: bigint;

async function A() {
const a = await p;
Expand Down Expand Up @@ -98,6 +99,7 @@ const p16 = p.catch(() => {});
const p17 = p.catch(() => {throw 1});
const p18 = p.catch(() => Promise.reject(1));
const p19 = p.catch(() => Promise.resolve(1));
const p19a = p.catch(() => b && Promise.resolve(1));

const p20 = p.then(undefined);
const p21 = p.then(null);
Expand All @@ -108,6 +110,7 @@ const p25 = p.then(() => null);
const p26 = p.then(() => {});
const p27 = p.then(() => {throw 1});
const p28 = p.then(() => Promise.resolve(1));
const p28a = p.then(() => b && Promise.resolve(1));
const p29 = p.then(() => Promise.reject(1));

const p30 = p.then(undefined, undefined);
Expand All @@ -119,6 +122,7 @@ const p35 = p.then(undefined, () => null);
const p36 = p.then(undefined, () => {});
const p37 = p.then(undefined, () => {throw 1});
const p38 = p.then(undefined, () => Promise.resolve(1));
const p38a = p.then(undefined, () => b && Promise.resolve(1));
const p39 = p.then(undefined, () => Promise.reject(1));

const p40 = p.then(null, undefined);
Expand All @@ -130,6 +134,7 @@ const p45 = p.then(null, () => null);
const p46 = p.then(null, () => {});
const p47 = p.then(null, () => {throw 1});
const p48 = p.then(null, () => Promise.resolve(1));
const p48a = p.then(null, () => b && Promise.resolve(1));
const p49 = p.then(null, () => Promise.reject(1));

const p50 = p.then(() => "1", undefined);
Expand All @@ -141,6 +146,7 @@ const p55 = p.then(() => "1", () => null);
const p56 = p.then(() => "1", () => {});
const p57 = p.then(() => "1", () => {throw 1});
const p58 = p.then(() => "1", () => Promise.resolve(1));
const p58a = p.then(() => "1", () => b && Promise.resolve(1));
const p59 = p.then(() => "1", () => Promise.reject(1));

const p60 = p.then(() => x, undefined);
Expand All @@ -152,6 +158,7 @@ const p65 = p.then(() => x, () => null);
const p66 = p.then(() => x, () => {});
const p67 = p.then(() => x, () => {throw 1});
const p68 = p.then(() => x, () => Promise.resolve(1));
const p68a = p.then(() => x, () => b && Promise.resolve(1));
const p69 = p.then(() => x, () => Promise.reject(1));

const p70 = p.then(() => undefined, undefined);
Expand All @@ -163,6 +170,7 @@ const p75 = p.then(() => undefined, () => null);
const p76 = p.then(() => undefined, () => {});
const p77 = p.then(() => undefined, () => {throw 1});
const p78 = p.then(() => undefined, () => Promise.resolve(1));
const p78a = p.then(() => undefined, () => b && Promise.resolve(1));
const p79 = p.then(() => undefined, () => Promise.reject(1));

const p80 = p.then(() => null, undefined);
Expand All @@ -174,6 +182,7 @@ const p85 = p.then(() => null, () => null);
const p86 = p.then(() => null, () => {});
const p87 = p.then(() => null, () => {throw 1});
const p88 = p.then(() => null, () => Promise.resolve(1));
const p88a = p.then(() => null, () => b && Promise.resolve(1));
const p89 = p.then(() => null, () => Promise.reject(1));

const p90 = p.then(() => {}, undefined);
Expand All @@ -185,6 +194,7 @@ const p95 = p.then(() => {}, () => null);
const p96 = p.then(() => {}, () => {});
const p97 = p.then(() => {}, () => {throw 1});
const p98 = p.then(() => {}, () => Promise.resolve(1));
const p98a = p.then(() => {}, () => b && Promise.resolve(1));
const p99 = p.then(() => {}, () => Promise.reject(1));

const pa0 = p.then(() => {throw 1}, undefined);
Expand All @@ -196,6 +206,7 @@ const pa5 = p.then(() => {throw 1}, () => null);
const pa6 = p.then(() => {throw 1}, () => {});
const pa7 = p.then(() => {throw 1}, () => {throw 1});
const pa8 = p.then(() => {throw 1}, () => Promise.resolve(1));
const pa8a = p.then(() => {throw 1}, () => b && Promise.resolve(1));
const pa9 = p.then(() => {throw 1}, () => Promise.reject(1));

const pb0 = p.then(() => Promise.resolve("1"), undefined);
Expand All @@ -207,6 +218,7 @@ const pb5 = p.then(() => Promise.resolve("1"), () => null);
const pb6 = p.then(() => Promise.resolve("1"), () => {});
const pb7 = p.then(() => Promise.resolve("1"), () => {throw 1});
const pb8 = p.then(() => Promise.resolve("1"), () => Promise.resolve(1));
const pb8a = p.then(() => Promise.resolve("1"), () => b && Promise.resolve(1));
const pb9 = p.then(() => Promise.resolve("1"), () => Promise.reject(1));

const pc0 = p.then(() => Promise.reject("1"), undefined);
Expand All @@ -218,13 +230,15 @@ const pc5 = p.then(() => Promise.reject("1"), () => null);
const pc6 = p.then(() => Promise.reject("1"), () => {});
const pc7 = p.then(() => Promise.reject("1"), () => {throw 1});
const pc8 = p.then(() => Promise.reject("1"), () => Promise.resolve(1));
const pc8a = p.then(() => Promise.reject("1"), () => b && Promise.resolve(1));
const pc9 = p.then(() => Promise.reject("1"), () => Promise.reject(1));

Promise.resolve(undefined as Promise<string> | number);
Promise.resolve(undefined as Promise<Promise<number>>);
Promise.resolve(undefined as string | Promise<Promise<number>>);
Promise.resolve(undefined as Promise<string> | Promise<Promise<number>>);
Promise.resolve(undefined as Promise<string | Promise<Promise<number>>>);
Promise.resolve(undefined as Promise<string | Promise<Promise<number>>>);


//// [promiseType.js]
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
Expand Down Expand Up @@ -337,6 +351,7 @@ const p16 = p.catch(() => { });
const p17 = p.catch(() => { throw 1; });
const p18 = p.catch(() => Promise.reject(1));
const p19 = p.catch(() => Promise.resolve(1));
const p19a = p.catch(() => b && Promise.resolve(1));
const p20 = p.then(undefined);
const p21 = p.then(null);
const p22 = p.then(() => 1);
Expand All @@ -346,6 +361,7 @@ const p25 = p.then(() => null);
const p26 = p.then(() => { });
const p27 = p.then(() => { throw 1; });
const p28 = p.then(() => Promise.resolve(1));
const p28a = p.then(() => b && Promise.resolve(1));
const p29 = p.then(() => Promise.reject(1));
const p30 = p.then(undefined, undefined);
const p31 = p.then(undefined, null);
Expand All @@ -356,6 +372,7 @@ const p35 = p.then(undefined, () => null);
const p36 = p.then(undefined, () => { });
const p37 = p.then(undefined, () => { throw 1; });
const p38 = p.then(undefined, () => Promise.resolve(1));
const p38a = p.then(undefined, () => b && Promise.resolve(1));
const p39 = p.then(undefined, () => Promise.reject(1));
const p40 = p.then(null, undefined);
const p41 = p.then(null, null);
Expand All @@ -366,6 +383,7 @@ const p45 = p.then(null, () => null);
const p46 = p.then(null, () => { });
const p47 = p.then(null, () => { throw 1; });
const p48 = p.then(null, () => Promise.resolve(1));
const p48a = p.then(null, () => b && Promise.resolve(1));
const p49 = p.then(null, () => Promise.reject(1));
const p50 = p.then(() => "1", undefined);
const p51 = p.then(() => "1", null);
Expand All @@ -376,6 +394,7 @@ const p55 = p.then(() => "1", () => null);
const p56 = p.then(() => "1", () => { });
const p57 = p.then(() => "1", () => { throw 1; });
const p58 = p.then(() => "1", () => Promise.resolve(1));
const p58a = p.then(() => "1", () => b && Promise.resolve(1));
const p59 = p.then(() => "1", () => Promise.reject(1));
const p60 = p.then(() => x, undefined);
const p61 = p.then(() => x, null);
Expand All @@ -386,6 +405,7 @@ const p65 = p.then(() => x, () => null);
const p66 = p.then(() => x, () => { });
const p67 = p.then(() => x, () => { throw 1; });
const p68 = p.then(() => x, () => Promise.resolve(1));
const p68a = p.then(() => x, () => b && Promise.resolve(1));
const p69 = p.then(() => x, () => Promise.reject(1));
const p70 = p.then(() => undefined, undefined);
const p71 = p.then(() => undefined, null);
Expand All @@ -396,6 +416,7 @@ const p75 = p.then(() => undefined, () => null);
const p76 = p.then(() => undefined, () => { });
const p77 = p.then(() => undefined, () => { throw 1; });
const p78 = p.then(() => undefined, () => Promise.resolve(1));
const p78a = p.then(() => undefined, () => b && Promise.resolve(1));
const p79 = p.then(() => undefined, () => Promise.reject(1));
const p80 = p.then(() => null, undefined);
const p81 = p.then(() => null, null);
Expand All @@ -406,6 +427,7 @@ const p85 = p.then(() => null, () => null);
const p86 = p.then(() => null, () => { });
const p87 = p.then(() => null, () => { throw 1; });
const p88 = p.then(() => null, () => Promise.resolve(1));
const p88a = p.then(() => null, () => b && Promise.resolve(1));
const p89 = p.then(() => null, () => Promise.reject(1));
const p90 = p.then(() => { }, undefined);
const p91 = p.then(() => { }, null);
Expand All @@ -416,6 +438,7 @@ const p95 = p.then(() => { }, () => null);
const p96 = p.then(() => { }, () => { });
const p97 = p.then(() => { }, () => { throw 1; });
const p98 = p.then(() => { }, () => Promise.resolve(1));
const p98a = p.then(() => { }, () => b && Promise.resolve(1));
const p99 = p.then(() => { }, () => Promise.reject(1));
const pa0 = p.then(() => { throw 1; }, undefined);
const pa1 = p.then(() => { throw 1; }, null);
Expand All @@ -426,6 +449,7 @@ const pa5 = p.then(() => { throw 1; }, () => null);
const pa6 = p.then(() => { throw 1; }, () => { });
const pa7 = p.then(() => { throw 1; }, () => { throw 1; });
const pa8 = p.then(() => { throw 1; }, () => Promise.resolve(1));
const pa8a = p.then(() => { throw 1; }, () => b && Promise.resolve(1));
const pa9 = p.then(() => { throw 1; }, () => Promise.reject(1));
const pb0 = p.then(() => Promise.resolve("1"), undefined);
const pb1 = p.then(() => Promise.resolve("1"), null);
Expand All @@ -436,6 +460,7 @@ const pb5 = p.then(() => Promise.resolve("1"), () => null);
const pb6 = p.then(() => Promise.resolve("1"), () => { });
const pb7 = p.then(() => Promise.resolve("1"), () => { throw 1; });
const pb8 = p.then(() => Promise.resolve("1"), () => Promise.resolve(1));
const pb8a = p.then(() => Promise.resolve("1"), () => b && Promise.resolve(1));
const pb9 = p.then(() => Promise.resolve("1"), () => Promise.reject(1));
const pc0 = p.then(() => Promise.reject("1"), undefined);
const pc1 = p.then(() => Promise.reject("1"), null);
Expand All @@ -446,6 +471,7 @@ const pc5 = p.then(() => Promise.reject("1"), () => null);
const pc6 = p.then(() => Promise.reject("1"), () => { });
const pc7 = p.then(() => Promise.reject("1"), () => { throw 1; });
const pc8 = p.then(() => Promise.reject("1"), () => Promise.resolve(1));
const pc8a = p.then(() => Promise.reject("1"), () => b && Promise.resolve(1));
const pc9 = p.then(() => Promise.reject("1"), () => Promise.reject(1));
Promise.resolve(undefined);
Promise.resolve(undefined);
Expand Down
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