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Merged
weswigham merged 3 commits into from
May 9, 2022
Merged

Fix type parameter comparability to consistently allow comparisons on unconstrained type parameters #48861

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57f17bb
Fix type parameter comparability to consistently allow comparisons on…
weswigham Apr 27, 2022
4c7e818
Less elaboration, non-strict-mode fix
weswigham Apr 27, 2022
25890ed
Merge branch 'main' into type-parameter-comparability
weswigham May 9, 2022
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Less elaboration, non-strict-mode fix
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@weswigham
weswigham committed Apr 27, 2022
commit 4c7e818d1403e7f40b558e4a28bd1619b1d400ed
6 changes: 3 additions & 3 deletions src/compiler/checker.ts
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Expand Up @@ -19564,20 +19564,20 @@ namespace ts {
// IndexedAccess comparisons are handled above in the `targetFlags & TypeFlage.IndexedAccess` branch
if (!(sourceFlags & TypeFlags.IndexedAccess && targetFlags & TypeFlags.IndexedAccess)) {
const constraint = getConstraintOfType(source as TypeVariable) || unknownType;
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@weswigham weswigham Apr 27, 2022

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This is the core of this fix. This is really all we need to make it so T extends unknown and a bare T are actually treated identically.

if (!strictNullChecks && (!constraint || (sourceFlags & TypeFlags.TypeParameter && constraint.flags & TypeFlags.Any))) {
if (!strictNullChecks && (!getConstraintOfType(source as TypeVariable) || (sourceFlags & TypeFlags.TypeParameter && constraint.flags & TypeFlags.Any))) {
// A type variable with no constraint is not related to the non-primitive object type.
if (result = isRelatedTo(emptyObjectType, extractTypesOfKind(target, ~TypeFlags.NonPrimitive), RecursionFlags.Both)) {
resetErrorInfo(saveErrorInfo);
return result;
}
}
// hi-speed no-this-instantiation check (less accurate, but avoids costly `this`-instantiation when the constraint will suffice), see #28231 for report on why this is needed
else if (result = isRelatedTo(constraint, target, RecursionFlags.Source, /*reportErrors*/ false, /*headMessage*/ undefined, intersectionState)) {
if (result = isRelatedTo(constraint, target, RecursionFlags.Source, /*reportErrors*/ false, /*headMessage*/ undefined, intersectionState)) {
resetErrorInfo(saveErrorInfo);
return result;
}
// slower, fuller, this-instantiated check (necessary when comparing raw `this` types from base classes), see `subclassWithPolymorphicThisIsAssignable.ts` test for example
else if (result = isRelatedTo(getTypeWithThisArgument(constraint, source), target, RecursionFlags.Source, reportErrors && !(targetFlags & sourceFlags & TypeFlags.TypeParameter), /*headMessage*/ undefined, intersectionState)) {
else if (result = isRelatedTo(getTypeWithThisArgument(constraint, source), target, RecursionFlags.Source, reportErrors && constraint !== unknownType && !(targetFlags & sourceFlags & TypeFlags.TypeParameter), /*headMessage*/ undefined, intersectionState)) {
resetErrorInfo(saveErrorInfo);
return result;
}
Expand Down
10 changes: 0 additions & 10 deletions tests/baselines/reference/assignmentCompatWithCallSignatures3.errors.txt
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Original file line number Diff line number Diff line change
@@ -1,19 +1,15 @@
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(47,1): error TS2322: Type '(x: number) => number[]' is not assignable to type '<T>(x: T) => T[]'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(50,1): error TS2322: Type '(x: number) => string[]' is not assignable to type '<T>(x: T) => string[]'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(53,1): error TS2322: Type '(x: number) => void' is not assignable to type '<T>(x: T) => T'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(56,1): error TS2322: Type '(x: string, y: number) => string' is not assignable to type '<T, U>(x: T, y: U) => T'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(59,1): error TS2322: Type '(x: (arg: string) => number) => string' is not assignable to type '<T, U>(x: (arg: T) => U) => T'.
Types of parameters 'x' and 'x' are incompatible.
Types of parameters 'arg' and 'arg' are incompatible.
Expand Down Expand Up @@ -64,7 +60,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
Types of property 'a' are incompatible.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.


==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts (15 errors) ====
Expand Down Expand Up @@ -119,31 +114,27 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '(x: number) => number[]' is not assignable to type '<T>(x: T) => T[]'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b2: <T>(x: T) => string[];
a2 = b2; // ok
b2 = a2; // ok
~~
!!! error TS2322: Type '(x: number) => string[]' is not assignable to type '<T>(x: T) => string[]'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b3: <T>(x: T) => T;
a3 = b3; // ok
b3 = a3; // ok
~~
!!! error TS2322: Type '(x: number) => void' is not assignable to type '<T>(x: T) => T'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b4: <T, U>(x: T, y: U) => T;
a4 = b4; // ok
b4 = a4; // ok
~~
!!! error TS2322: Type '(x: string, y: number) => string' is not assignable to type '<T, U>(x: T, y: U) => T'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
var b5: <T, U>(x: (arg: T) => U) => T;
a5 = b5; // ok
b5 = a5; // ok
Expand Down Expand Up @@ -236,7 +227,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
!!! error TS2322: Types of property 'a' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
var b15: <T>(x: T) => T[];
a15 = b15; // ok
b15 = a15; // ok
Expand Down
8 changes: 0 additions & 8 deletions tests/baselines/reference/assignmentCompatWithCallSignatures4.errors.txt
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@@ -1,7 +1,6 @@
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(45,9): error TS2322: Type '(x: number) => string[]' is not assignable to type '<T, U>(x: T) => U[]'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(49,9): error TS2322: Type '(x: (arg: Base) => Derived) => (r: Base) => Derived2' is not assignable to type '<T extends Base, U extends Derived, V extends Derived2>(x: (arg: T) => U) => (r: T) => V'.
Types of parameters 'x' and 'x' are incompatible.
Types of parameters 'arg' and 'arg' are incompatible.
Expand Down Expand Up @@ -37,7 +36,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
Types of property 'a' are incompatible.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(73,9): error TS2322: Type '<T extends Base>(x: { a: T; b: T; }) => number' is not assignable to type '(x: { a: string; b: number; }) => number'.
Types of parameters 'x' and 'x' are incompatible.
Type '{ a: string; b: number; }' is not assignable to type '{ a: Base; b: Base; }'.
Expand All @@ -56,11 +54,9 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(90,9): error TS2322: Type '<T>(x: T) => T[]' is not assignable to type '<T>(x: T) => string[]'.
Type 'T[]' is not assignable to type 'string[]'.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(95,9): error TS2322: Type '<T>(x: T) => T[]' is not assignable to type '<T>(x: T) => string[]'.
Type 'T[]' is not assignable to type 'string[]'.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(96,9): error TS2322: Type '<T>(x: T) => string[]' is not assignable to type '<T>(x: T) => T[]'.
Type 'string[]' is not assignable to type 'T[]'.
Type 'string' is not assignable to type 'T'.
Expand Down Expand Up @@ -117,7 +113,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '(x: number) => string[]' is not assignable to type '<T, U>(x: T) => U[]'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.

var b7: <T extends Base, U extends Derived, V extends Derived2>(x: (arg: T) => U) => (r: T) => V;
a7 = b7;
Expand Down Expand Up @@ -186,7 +181,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
!!! error TS2322: Types of property 'a' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.

var b15a: <T extends Base>(x: { a: T; b: T }) => number;
a15 = b15a;
Expand Down Expand Up @@ -229,7 +223,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '<T>(x: T) => T[]' is not assignable to type '<T>(x: T) => string[]'.
!!! error TS2322: Type 'T[]' is not assignable to type 'string[]'.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.

// target type has generic call signature
var a3: <T>(x: T) => string[];
Expand All @@ -239,7 +232,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '<T>(x: T) => T[]' is not assignable to type '<T>(x: T) => string[]'.
!!! error TS2322: Type 'T[]' is not assignable to type 'string[]'.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
b3 = a3;
~~
!!! error TS2322: Type '<T>(x: T) => string[]' is not assignable to type '<T>(x: T) => T[]'.
Expand Down
3 changes: 0 additions & 3 deletions tests/baselines/reference/assignmentCompatWithCallSignatures5.errors.txt
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Expand Up @@ -18,7 +18,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
Type '{ a: U; b: V; }' is not assignable to type '{ a: Base; b: Base; }'.
Types of property 'a' are incompatible.
Type 'U' is not assignable to type 'Base'.
Property 'foo' is missing in type '{}' but required in type 'Base'.


==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts (4 errors) ====
Expand Down Expand Up @@ -104,8 +103,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '{ a: U; b: V; }' is not assignable to type '{ a: Base; b: Base; }'.
!!! error TS2322: Types of property 'a' are incompatible.
!!! error TS2322: Type 'U' is not assignable to type 'Base'.
!!! error TS2322: Property 'foo' is missing in type '{}' but required in type 'Base'.
!!! related TS2728 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts:3:14: 'foo' is declared here.
var b17: <T>(x: (a: T) => T) => T[];
a17 = b17; // ok
b17 = a17; // ok
Expand Down
5 changes: 1 addition & 4 deletions tests/baselines/reference/assignmentCompatWithCallSignatures6.errors.txt
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Expand Up @@ -12,7 +12,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
Type '{ a: T; b: T; }' is not assignable to type '{ a: Base; b: Base; }'.
Types of property 'a' are incompatible.
Type 'T' is not assignable to type 'Base'.
Property 'foo' is missing in type '{}' but required in type 'Base'.


==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts (3 errors) ====
Expand Down Expand Up @@ -74,6 +73,4 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type '{ a: T; b: T; }' is not assignable to type '{ a: Base; b: Base; }'.
!!! error TS2322: Types of property 'a' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'Base'.
!!! error TS2322: Property 'foo' is missing in type '{}' but required in type 'Base'.
!!! related TS2728 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts:3:14: 'foo' is declared here.
!!! error TS2322: Type 'T' is not assignable to type 'Base'.
10 changes: 0 additions & 10 deletions tests/baselines/reference/assignmentCompatWithConstructSignatures3.errors.txt
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@@ -1,19 +1,15 @@
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(47,1): error TS2322: Type 'new (x: number) => number[]' is not assignable to type 'new <T>(x: T) => T[]'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(50,1): error TS2322: Type 'new (x: number) => string[]' is not assignable to type 'new <T>(x: T) => string[]'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(53,1): error TS2322: Type 'new (x: number) => void' is not assignable to type 'new <T>(x: T) => T'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'number'.
Type 'unknown' is not assignable to type 'number'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(56,1): error TS2322: Type 'new (x: string, y: number) => string' is not assignable to type 'new <T, U>(x: T, y: U) => T'.
Types of parameters 'x' and 'x' are incompatible.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(59,1): error TS2322: Type 'new (x: (arg: string) => number) => string' is not assignable to type 'new <T, U>(x: (arg: T) => U) => T'.
Types of parameters 'x' and 'x' are incompatible.
Types of parameters 'arg' and 'arg' are incompatible.
Expand Down Expand Up @@ -64,7 +60,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
Types of property 'a' are incompatible.
Type 'T' is not assignable to type 'string'.
Type 'unknown' is not assignable to type 'string'.


==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts (15 errors) ====
Expand Down Expand Up @@ -119,31 +114,27 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type 'new (x: number) => number[]' is not assignable to type 'new <T>(x: T) => T[]'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b2: new <T>(x: T) => string[];
a2 = b2; // ok
b2 = a2; // ok
~~
!!! error TS2322: Type 'new (x: number) => string[]' is not assignable to type 'new <T>(x: T) => string[]'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b3: new <T>(x: T) => T;
a3 = b3; // ok
b3 = a3; // ok
~~
!!! error TS2322: Type 'new (x: number) => void' is not assignable to type 'new <T>(x: T) => T'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'number'.
!!! error TS2322: Type 'unknown' is not assignable to type 'number'.
var b4: new <T, U>(x: T, y: U) => T;
a4 = b4; // ok
b4 = a4; // ok
~~
!!! error TS2322: Type 'new (x: string, y: number) => string' is not assignable to type 'new <T, U>(x: T, y: U) => T'.
!!! error TS2322: Types of parameters 'x' and 'x' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
var b5: new <T, U>(x: (arg: T) => U) => T;
a5 = b5; // ok
b5 = a5; // ok
Expand Down Expand Up @@ -236,7 +227,6 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
!!! error TS2322: Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
!!! error TS2322: Types of property 'a' are incompatible.
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
var b15: new <T>(x: T) => T[];
a15 = b15; // ok
b15 = a15; // ok
Expand Down
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