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ahejlsbergahejlsberg
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Merge pull request #30363 from Microsoft/fixTypeParameterPromotion
Higher order type parameter promotion fixes
2 parents 6587980 + e9eb73b commit 36cf12f

10 files changed

+724
-285
lines changed

‎src/compiler/checker.ts

Lines changed: 54 additions & 62 deletions
Large diffs are not rendered by default.

‎tests/baselines/reference/contravariantInferenceAndTypeGuard.js

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//// [contravariantInferenceAndTypeGuard.ts]
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interface ListItem<TData> {
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prev: ListItem<TData> | null;
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next: ListItem<TData> | null;
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data: TData;
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}
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type IteratorFn<TData, TResult, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => TResult;
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type FilterFn<TData, TResult extends TData, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => item is TResult;
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declare class List<TData> {
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filter<TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>;
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filter<TResult extends TData>(fn: FilterFn<TData, TResult>): List<TResult>;
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filter<TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>;
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filter(fn: IteratorFn<TData, boolean>): List<TData>;
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}
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interface Test {
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a: string;
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}
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const list2 = new List<Test | null>();
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const filter1 = list2.filter(function(item, node, list): item is Test {
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this.b; // $ExpectType string
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item; // $ExpectType Test | null
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node; // $ExpectType ListItem<Test | null>
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list; // $ExpectType List<Test | null>
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return !!item;
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}, {b: 'c'});
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const x: List<Test> = filter1; // $ExpectType List<Test>
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//// [contravariantInferenceAndTypeGuard.js]
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"use strict";
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var list2 = new List();
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var filter1 = list2.filter(function (item, node, list) {
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this.b; // $ExpectType string
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item; // $ExpectType Test | null
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node; // $ExpectType ListItem<Test | null>
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list; // $ExpectType List<Test | null>
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return !!item;
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}, { b: 'c' });
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var x = filter1; // $ExpectType List<Test>

‎tests/baselines/reference/contravariantInferenceAndTypeGuard.symbols

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=== tests/cases/compiler/contravariantInferenceAndTypeGuard.ts ===
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interface ListItem<TData> {
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>ListItem : Symbol(ListItem, Decl(contravariantInferenceAndTypeGuard.ts, 0, 0))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 0, 19))
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prev: ListItem<TData> | null;
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>prev : Symbol(ListItem.prev, Decl(contravariantInferenceAndTypeGuard.ts, 0, 27))
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>ListItem : Symbol(ListItem, Decl(contravariantInferenceAndTypeGuard.ts, 0, 0))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 0, 19))
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next: ListItem<TData> | null;
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>next : Symbol(ListItem.next, Decl(contravariantInferenceAndTypeGuard.ts, 1, 33))
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>ListItem : Symbol(ListItem, Decl(contravariantInferenceAndTypeGuard.ts, 0, 0))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 0, 19))
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data: TData;
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>data : Symbol(ListItem.data, Decl(contravariantInferenceAndTypeGuard.ts, 2, 33))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 0, 19))
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}
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type IteratorFn<TData, TResult, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => TResult;
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>IteratorFn : Symbol(IteratorFn, Decl(contravariantInferenceAndTypeGuard.ts, 4, 1))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 5, 16))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 5, 22))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 5, 31))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 5, 16))
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>this : Symbol(this, Decl(contravariantInferenceAndTypeGuard.ts, 5, 59))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 5, 31))
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>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 5, 74))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 5, 16))
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>node : Symbol(node, Decl(contravariantInferenceAndTypeGuard.ts, 5, 87))
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>ListItem : Symbol(ListItem, Decl(contravariantInferenceAndTypeGuard.ts, 0, 0))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 5, 16))
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>list : Symbol(list, Decl(contravariantInferenceAndTypeGuard.ts, 5, 110))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 5, 16))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 5, 22))
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type FilterFn<TData, TResult extends TData, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => item is TResult;
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>FilterFn : Symbol(FilterFn, Decl(contravariantInferenceAndTypeGuard.ts, 5, 141))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 6, 20))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 6, 43))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>this : Symbol(this, Decl(contravariantInferenceAndTypeGuard.ts, 6, 71))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 6, 43))
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>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 6, 86))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>node : Symbol(node, Decl(contravariantInferenceAndTypeGuard.ts, 6, 99))
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>ListItem : Symbol(ListItem, Decl(contravariantInferenceAndTypeGuard.ts, 0, 0))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>list : Symbol(list, Decl(contravariantInferenceAndTypeGuard.ts, 6, 122))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 6, 14))
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>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 6, 86))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 6, 20))
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declare class List<TData> {
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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filter<TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>;
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>filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 9, 11))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 9, 20))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>fn : Symbol(fn, Decl(contravariantInferenceAndTypeGuard.ts, 9, 44))
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>FilterFn : Symbol(FilterFn, Decl(contravariantInferenceAndTypeGuard.ts, 5, 141))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 9, 20))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 9, 11))
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>context : Symbol(context, Decl(contravariantInferenceAndTypeGuard.ts, 9, 83))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 9, 11))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 9, 20))
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filter<TResult extends TData>(fn: FilterFn<TData, TResult>): List<TResult>;
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>filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 10, 11))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>fn : Symbol(fn, Decl(contravariantInferenceAndTypeGuard.ts, 10, 34))
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>FilterFn : Symbol(FilterFn, Decl(contravariantInferenceAndTypeGuard.ts, 5, 141))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 10, 11))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TResult : Symbol(TResult, Decl(contravariantInferenceAndTypeGuard.ts, 10, 11))
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filter<TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>;
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>filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 11, 11))
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>fn : Symbol(fn, Decl(contravariantInferenceAndTypeGuard.ts, 11, 21))
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>IteratorFn : Symbol(IteratorFn, Decl(contravariantInferenceAndTypeGuard.ts, 4, 1))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 11, 11))
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>context : Symbol(context, Decl(contravariantInferenceAndTypeGuard.ts, 11, 62))
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>TContext : Symbol(TContext, Decl(contravariantInferenceAndTypeGuard.ts, 11, 11))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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filter(fn: IteratorFn<TData, boolean>): List<TData>;
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>filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
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>fn : Symbol(fn, Decl(contravariantInferenceAndTypeGuard.ts, 12, 11))
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>IteratorFn : Symbol(IteratorFn, Decl(contravariantInferenceAndTypeGuard.ts, 4, 1))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>TData : Symbol(TData, Decl(contravariantInferenceAndTypeGuard.ts, 8, 19))
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}
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interface Test {
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>Test : Symbol(Test, Decl(contravariantInferenceAndTypeGuard.ts, 13, 1))
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a: string;
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>a : Symbol(Test.a, Decl(contravariantInferenceAndTypeGuard.ts, 14, 16))
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}
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const list2 = new List<Test | null>();
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>list2 : Symbol(list2, Decl(contravariantInferenceAndTypeGuard.ts, 17, 5))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>Test : Symbol(Test, Decl(contravariantInferenceAndTypeGuard.ts, 13, 1))
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const filter1 = list2.filter(function(item, node, list): item is Test {
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>filter1 : Symbol(filter1, Decl(contravariantInferenceAndTypeGuard.ts, 18, 5))
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>list2.filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
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>list2 : Symbol(list2, Decl(contravariantInferenceAndTypeGuard.ts, 17, 5))
125+
>filter : Symbol(List.filter, Decl(contravariantInferenceAndTypeGuard.ts, 8, 27), Decl(contravariantInferenceAndTypeGuard.ts, 9, 118), Decl(contravariantInferenceAndTypeGuard.ts, 10, 79), Decl(contravariantInferenceAndTypeGuard.ts, 11, 95))
126+
>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 18, 38))
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>node : Symbol(node, Decl(contravariantInferenceAndTypeGuard.ts, 18, 43))
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>list : Symbol(list, Decl(contravariantInferenceAndTypeGuard.ts, 18, 49))
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>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 18, 38))
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>Test : Symbol(Test, Decl(contravariantInferenceAndTypeGuard.ts, 13, 1))
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this.b; // $ExpectType string
133+
>this.b : Symbol(b, Decl(contravariantInferenceAndTypeGuard.ts, 24, 4))
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>this : Symbol(this, Decl(contravariantInferenceAndTypeGuard.ts, 6, 71))
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>b : Symbol(b, Decl(contravariantInferenceAndTypeGuard.ts, 24, 4))
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item; // $ExpectType Test | null
138+
>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 18, 38))
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node; // $ExpectType ListItem<Test | null>
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>node : Symbol(node, Decl(contravariantInferenceAndTypeGuard.ts, 18, 43))
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list; // $ExpectType List<Test | null>
144+
>list : Symbol(list, Decl(contravariantInferenceAndTypeGuard.ts, 18, 49))
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return !!item;
147+
>item : Symbol(item, Decl(contravariantInferenceAndTypeGuard.ts, 18, 38))
148+
149+
}, {b: 'c'});
150+
>b : Symbol(b, Decl(contravariantInferenceAndTypeGuard.ts, 24, 4))
151+
152+
const x: List<Test> = filter1; // $ExpectType List<Test>
153+
>x : Symbol(x, Decl(contravariantInferenceAndTypeGuard.ts, 25, 5))
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>List : Symbol(List, Decl(contravariantInferenceAndTypeGuard.ts, 6, 161))
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>Test : Symbol(Test, Decl(contravariantInferenceAndTypeGuard.ts, 13, 1))
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>filter1 : Symbol(filter1, Decl(contravariantInferenceAndTypeGuard.ts, 18, 5))
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‎tests/baselines/reference/contravariantInferenceAndTypeGuard.types

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=== tests/cases/compiler/contravariantInferenceAndTypeGuard.ts ===
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interface ListItem<TData> {
3+
prev: ListItem<TData> | null;
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>prev : ListItem<TData> | null
5+
>null : null
6+
7+
next: ListItem<TData> | null;
8+
>next : ListItem<TData> | null
9+
>null : null
10+
11+
data: TData;
12+
>data : TData
13+
}
14+
type IteratorFn<TData, TResult, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => TResult;
15+
>IteratorFn : IteratorFn<TData, TResult, TContext>
16+
>this : TContext
17+
>item : TData
18+
>node : ListItem<TData>
19+
>list : List<TData>
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21+
type FilterFn<TData, TResult extends TData, TContext = List<TData>> = (this: TContext, item: TData, node: ListItem<TData>, list: List<TData>) => item is TResult;
22+
>FilterFn : FilterFn<TData, TResult, TContext>
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>this : TContext
24+
>item : TData
25+
>node : ListItem<TData>
26+
>list : List<TData>
27+
28+
declare class List<TData> {
29+
>List : List<TData>
30+
31+
filter<TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>;
32+
>filter : { <TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>; <TResult extends TData>(fn: FilterFn<TData, TResult, List<TData>>): List<TResult>; <TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>; (fn: IteratorFn<TData, boolean, List<TData>>): List<TData>; }
33+
>fn : FilterFn<TData, TResult, TContext>
34+
>context : TContext
35+
36+
filter<TResult extends TData>(fn: FilterFn<TData, TResult>): List<TResult>;
37+
>filter : { <TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>; <TResult extends TData>(fn: FilterFn<TData, TResult, List<TData>>): List<TResult>; <TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>; (fn: IteratorFn<TData, boolean, List<TData>>): List<TData>; }
38+
>fn : FilterFn<TData, TResult, List<TData>>
39+
40+
filter<TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>;
41+
>filter : { <TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>; <TResult extends TData>(fn: FilterFn<TData, TResult, List<TData>>): List<TResult>; <TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>; (fn: IteratorFn<TData, boolean, List<TData>>): List<TData>; }
42+
>fn : IteratorFn<TData, boolean, TContext>
43+
>context : TContext
44+
45+
filter(fn: IteratorFn<TData, boolean>): List<TData>;
46+
>filter : { <TContext, TResult extends TData>(fn: FilterFn<TData, TResult, TContext>, context: TContext): List<TResult>; <TResult extends TData>(fn: FilterFn<TData, TResult, List<TData>>): List<TResult>; <TContext>(fn: IteratorFn<TData, boolean, TContext>, context: TContext): List<TData>; (fn: IteratorFn<TData, boolean, List<TData>>): List<TData>; }
47+
>fn : IteratorFn<TData, boolean, List<TData>>
48+
}
49+
interface Test {
50+
a: string;
51+
>a : string
52+
}
53+
const list2 = new List<Test | null>();
54+
>list2 : List<Test | null>
55+
>new List<Test | null>() : List<Test | null>
56+
>List : typeof List
57+
>null : null
58+
59+
const filter1 = list2.filter(function(item, node, list): item is Test {
60+
>filter1 : List<Test>
61+
>list2.filter(function(item, node, list): item is Test { this.b; // $ExpectType string item; // $ExpectType Test | null node; // $ExpectType ListItem<Test | null> list; // $ExpectType List<Test | null> return !!item;}, {b: 'c'}) : List<Test>
62+
>list2.filter : { <TContext, TResult extends Test | null>(fn: FilterFn<Test | null, TResult, TContext>, context: TContext): List<TResult>; <TResult extends Test | null>(fn: FilterFn<Test | null, TResult, List<Test | null>>): List<TResult>; <TContext>(fn: IteratorFn<Test | null, boolean, TContext>, context: TContext): List<Test | null>; (fn: IteratorFn<Test | null, boolean, List<Test | null>>): List<Test | null>; }
63+
>list2 : List<Test | null>
64+
>filter : { <TContext, TResult extends Test | null>(fn: FilterFn<Test | null, TResult, TContext>, context: TContext): List<TResult>; <TResult extends Test | null>(fn: FilterFn<Test | null, TResult, List<Test | null>>): List<TResult>; <TContext>(fn: IteratorFn<Test | null, boolean, TContext>, context: TContext): List<Test | null>; (fn: IteratorFn<Test | null, boolean, List<Test | null>>): List<Test | null>; }
65+
>function(item, node, list): item is Test { this.b; // $ExpectType string item; // $ExpectType Test | null node; // $ExpectType ListItem<Test | null> list; // $ExpectType List<Test | null> return !!item;} : (this: { b: string; }, item: Test | null, node: ListItem<Test | null>, list: List<Test | null>) => item is Test
66+
>item : Test | null
67+
>node : ListItem<Test | null>
68+
>list : List<Test | null>
69+
70+
this.b; // $ExpectType string
71+
>this.b : string
72+
>this : { b: string; }
73+
>b : string
74+
75+
item; // $ExpectType Test | null
76+
>item : Test | null
77+
78+
node; // $ExpectType ListItem<Test | null>
79+
>node : ListItem<Test | null>
80+
81+
list; // $ExpectType List<Test | null>
82+
>list : List<Test | null>
83+
84+
return !!item;
85+
>!!item : boolean
86+
>!item : boolean
87+
>item : Test | null
88+
89+
}, {b: 'c'});
90+
>{b: 'c'} : { b: string; }
91+
>b : string
92+
>'c' : "c"
93+
94+
const x: List<Test> = filter1; // $ExpectType List<Test>
95+
>x : List<Test>
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>filter1 : List<Test>
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‎tests/baselines/reference/genericFunctionInference1.errors.txt

Lines changed: 11 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
tests/cases/compiler/genericFunctionInference1.ts(83,14): error TS2345: Argument of type '<a>(value: { key: a; }) => a' is not assignable to parameter of type '(value: Data) => string'.
1+
tests/cases/compiler/genericFunctionInference1.ts(88,14): error TS2345: Argument of type '<a>(value: { key: a; }) => a' is not assignable to parameter of type '(value: Data) => string'.
22
Type 'number' is not assignable to type 'string'.
33

44

@@ -62,6 +62,11 @@ tests/cases/compiler/genericFunctionInference1.ts(83,14): error TS2345: Argument
6262

6363
const f50 = pipe5(list); // No higher order inference
6464

65+
declare function wrap3<A, B, C>(f: (a: A, b1: B, b2: B) => C): (a: A, b1: B, b2: B) => C;
66+
declare function baz<T, U extends T>(t1: T, t2: T, u: U): [T, U];
67+
68+
let f60 = wrap3(baz);
69+
6570
// #417
6671

6772
function mirror<A, B>(f: (a: A) => B): (a: A) => B { return f; }
@@ -198,4 +203,9 @@ tests/cases/compiler/genericFunctionInference1.ts(83,14): error TS2345: Argument
198203
foo2(() => {});
199204
foo2(identity);
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foo2(identity, 1);
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// Repro from #30324
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declare function times<T>(fn: (i: number) => T): (n: number) => T[];
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const a2 = times(identity)(5); // => [0, 1, 2, 3, 4]
201211

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