Go back to instantiating only conditional types

Author: Andarist

src/compiler/checker.ts

@@ -30754,7 +30754,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             // replaced with their constraints similar to the apparent type.
             if (
                 inferenceContext &&
-                (contextFlags! & ContextFlags.Signature || maybeTypeOfKind(contextualType, TypeFlags.Simplifiable)) &&
+                (contextFlags! & ContextFlags.Signature || maybeTypeOfKind(contextualType, TypeFlags.Conditional)) &&
                 some(inferenceContext.inferences, hasInferenceCandidatesOrDefault)
             ) {
                 // For contextual signatures we incorporate all inferences made so far, e.g. from return

tests/baselines/reference/contextualInnerCallFromIndexedAccessType.symbols

@@ -1,5 +1,5 @@
-reverseMappedTypeIntersectionConstraint.ts(22,3): error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: string; states: { a: { entry: string; }; }; }'.
-reverseMappedTypeIntersectionConstraint.ts(32,3): error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: string; states: { a: { entry: string; }; }; }'.
+reverseMappedTypeIntersectionConstraint.ts(19,7): error TS2322: Type '"bar"' is not assignable to type '"foo"'.
+reverseMappedTypeIntersectionConstraint.ts(32,3): error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: "foo"; states: { a: { entry: "foo"; }; }; }'.
 reverseMappedTypeIntersectionConstraint.ts(43,3): error TS2353: Object literal may only specify known properties, and 'z' does not exist in type '{ x: number; y: "y"; }'.
 reverseMappedTypeIntersectionConstraint.ts(59,7): error TS2322: Type '{ [K in keyof T & keyof Stuff]: T[K]; }' is not assignable to type 'T'.
   '{ [K in keyof T & keyof Stuff]: T[K]; }' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'Stuff'.
@@ -37,11 +37,12 @@ reverseMappedTypeIntersectionConstraint.ts(171,3): error TS2353: Object literal
       states: {
         a: {
           entry: "bar",
+          ~~~~~
+!!! error TS2322: Type '"bar"' is not assignable to type '"foo"'.
+!!! related TS6500 reverseMappedTypeIntersectionConstraint.ts:2:3: The expected type comes from property 'entry' which is declared here on type 'StateConfig<"foo">'
         },
       },
       extra: 12,
-      ~~~~~
-!!! error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: string; states: { a: { entry: string; }; }; }'.
     });
 
     const inferredParams2 = createMachine({
@@ -53,7 +54,7 @@ reverseMappedTypeIntersectionConstraint.ts(171,3): error TS2353: Object literal
       },
       extra: 12,
       ~~~~~
-!!! error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: string; states: { a: { entry: string; }; }; }'.
+!!! error TS2353: Object literal may only specify known properties, and 'extra' does not exist in type '{ entry: "foo"; states: { a: { entry: "foo"; }; }; }'.
     });
 
 

tests/baselines/reference/contextualInnerCallFromIndexedAccessType.types

@@ -29,25 +29,25 @@ declare function createMachine<
 >config : { [K in keyof TConfig & keyof StateConfig<any>]: TConfig[K]; }
 
 const inferredParams1 = createMachine({
->inferredParams1 : [string, { entry: string; states: { a: { entry: string; }; }; }]
->createMachine({  entry: "foo",  states: {    a: {      entry: "bar",    },  },  extra: 12,}) : [string, { entry: string; states: { a: { entry: string; }; }; }]
+>inferredParams1 : ["foo", StateConfig<"foo">]
+>createMachine({  entry: "foo",  states: {    a: {      entry: "bar",    },  },  extra: 12,}) : ["foo", StateConfig<"foo">]
 >createMachine : <TConfig extends StateConfig<TAction>, TAction extends string = TConfig["entry"] extends string ? TConfig["entry"] : string>(config: { [K in keyof TConfig & keyof StateConfig<any>]: TConfig[K]; }) => [TAction, TConfig]
->{  entry: "foo",  states: {    a: {      entry: "bar",    },  },  extra: 12,} : { entry: string; states: { a: { entry: string; }; }; extra: number; }
+>{  entry: "foo",  states: {    a: {      entry: "bar",    },  },  extra: 12,} : { entry: "foo"; states: { a: { entry: "bar"; }; }; extra: number; }
 
   entry: "foo",
->entry : string
+>entry : "foo"
 >"foo" : "foo"
 
   states: {
->states : { a: { entry: string; }; }
->{    a: {      entry: "bar",    },  } : { a: { entry: string; }; }
+>states : { a: { entry: "bar"; }; }
+>{    a: {      entry: "bar",    },  } : { a: { entry: "bar"; }; }
 
     a: {
->a : { entry: string; }
->{      entry: "bar",    } : { entry: string; }
+>a : { entry: "bar"; }
+>{      entry: "bar",    } : { entry: "bar"; }
 
       entry: "bar",
->entry : string
+>entry : "bar"
 >"bar" : "bar"
 
     },
@@ -59,25 +59,25 @@ const inferredParams1 = createMachine({
 });
 
 const inferredParams2 = createMachine({
->inferredParams2 : [string, { entry: string; states: { a: { entry: string; }; }; }]
->createMachine({  entry: "foo",  states: {    a: {      entry: "foo",    },  },  extra: 12,}) : [string, { entry: string; states: { a: { entry: string; }; }; }]
+>inferredParams2 : ["foo", { entry: "foo"; states: { a: { entry: "foo"; }; }; }]
+>createMachine({  entry: "foo",  states: {    a: {      entry: "foo",    },  },  extra: 12,}) : ["foo", { entry: "foo"; states: { a: { entry: "foo"; }; }; }]
 >createMachine : <TConfig extends StateConfig<TAction>, TAction extends string = TConfig["entry"] extends string ? TConfig["entry"] : string>(config: { [K in keyof TConfig & keyof StateConfig<any>]: TConfig[K]; }) => [TAction, TConfig]
->{  entry: "foo",  states: {    a: {      entry: "foo",    },  },  extra: 12,} : { entry: string; states: { a: { entry: string; }; }; extra: number; }
+>{  entry: "foo",  states: {    a: {      entry: "foo",    },  },  extra: 12,} : { entry: "foo"; states: { a: { entry: "foo"; }; }; extra: number; }
 
   entry: "foo",
->entry : string
+>entry : "foo"
 >"foo" : "foo"
 
   states: {
->states : { a: { entry: string; }; }
->{    a: {      entry: "foo",    },  } : { a: { entry: string; }; }
+>states : { a: { entry: "foo"; }; }
+>{    a: {      entry: "foo",    },  } : { a: { entry: "foo"; }; }
 
     a: {
->a : { entry: string; }
->{      entry: "foo",    } : { entry: string; }
+>a : { entry: "foo"; }
+>{      entry: "foo",    } : { entry: "foo"; }
 
       entry: "foo",
->entry : string
+>entry : "foo"
 >"foo" : "foo"
 
     },