controlFlowGenericTypes.symbols

=== tests/cases/conformance/controlFlow/controlFlowGenericTypes.ts ===
function f1<T extends string | undefined>(x: T, y: { a: T }, z: [T]): string {
>f1 : Symbol(f1, Decl(controlFlowGenericTypes.ts, 0, 0))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 0, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 0, 42))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 0, 12))
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 0, 47))
>a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 0, 12))
>z : Symbol(z, Decl(controlFlowGenericTypes.ts, 0, 60))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 0, 12))

    if (x) {
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 0, 42))

        x;
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 0, 42))

        x.length;
>x.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 0, 42))
>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))

        return x;
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 0, 42))
    }
    if (y.a) {
>y.a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 0, 47))
>a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))

        y.a.length;
>y.a.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
>y.a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 0, 47))
>a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))

        return y.a;
>y.a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 0, 47))
>a : Symbol(a, Decl(controlFlowGenericTypes.ts, 0, 52))
    }
    if (z[0]) {
>z : Symbol(z, Decl(controlFlowGenericTypes.ts, 0, 60))
>0 : Symbol(0)

        z[0].length;
>z[0].length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
>z : Symbol(z, Decl(controlFlowGenericTypes.ts, 0, 60))
>0 : Symbol(0)
>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))

        return z[0];
>z : Symbol(z, Decl(controlFlowGenericTypes.ts, 0, 60))
>0 : Symbol(0)
    }
    return "hello";
}

function f2<T>(x: Extract<T, string | undefined> | null): string {
>f2 : Symbol(f2, Decl(controlFlowGenericTypes.ts, 15, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 17, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 17, 15))
>Extract : Symbol(Extract, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 17, 12))

    if (x) {
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 17, 15))

        x;
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 17, 15))

        x.length;
>x.length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 17, 15))
>length : Symbol(String.length, Decl(lib.es5.d.ts, --, --))

        return x;
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 17, 15))
    }
    return "hello";
}

interface Box<T> {
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 26, 14))

    item: T;
>item : Symbol(Box.item, Decl(controlFlowGenericTypes.ts, 26, 18))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 26, 14))
}

declare function isBox(x: any): x is Box<unknown>;
>isBox : Symbol(isBox, Decl(controlFlowGenericTypes.ts, 28, 1))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 30, 23))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 30, 23))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))

declare function isUndefined(x: unknown): x is undefined;
>isUndefined : Symbol(isUndefined, Decl(controlFlowGenericTypes.ts, 30, 50))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 31, 29))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 31, 29))

declare function unbox<T>(x: Box<T>): T;
>unbox : Symbol(unbox, Decl(controlFlowGenericTypes.ts, 31, 57))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 32, 23))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 32, 26))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 32, 23))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 32, 23))

function g1<T extends Box<T> | undefined>(x: T) {
>g1 : Symbol(g1, Decl(controlFlowGenericTypes.ts, 32, 40))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 34, 12))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 34, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 34, 42))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 34, 12))

    if (isBox(x)) {
>isBox : Symbol(isBox, Decl(controlFlowGenericTypes.ts, 28, 1))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 34, 42))

        unbox(x);
>unbox : Symbol(unbox, Decl(controlFlowGenericTypes.ts, 31, 57))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 34, 42))
    }
}

function g2<T extends Box<T> | undefined>(x: T) {
>g2 : Symbol(g2, Decl(controlFlowGenericTypes.ts, 38, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 40, 12))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 40, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 40, 42))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 40, 12))

    if (!isUndefined(x)) {
>isUndefined : Symbol(isUndefined, Decl(controlFlowGenericTypes.ts, 30, 50))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 40, 42))

        unbox(x);
>unbox : Symbol(unbox, Decl(controlFlowGenericTypes.ts, 31, 57))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 40, 42))
    }
}

function g3<T extends Box<T> | undefined>(x: T) {
>g3 : Symbol(g3, Decl(controlFlowGenericTypes.ts, 44, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 46, 12))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 46, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 46, 42))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 46, 12))

    if (!isBox(x)) {
>isBox : Symbol(isBox, Decl(controlFlowGenericTypes.ts, 28, 1))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 46, 42))

        unbox(x);  // Error
>unbox : Symbol(unbox, Decl(controlFlowGenericTypes.ts, 31, 57))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 46, 42))
    }
}

function g4<T extends Box<T> | undefined>(x: T) {
>g4 : Symbol(g4, Decl(controlFlowGenericTypes.ts, 50, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 52, 12))
>Box : Symbol(Box, Decl(controlFlowGenericTypes.ts, 24, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 52, 12))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 52, 42))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 52, 12))

    if (isUndefined(x)) {
>isUndefined : Symbol(isUndefined, Decl(controlFlowGenericTypes.ts, 30, 50))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 52, 42))

        unbox(x);  // Error
>unbox : Symbol(unbox, Decl(controlFlowGenericTypes.ts, 31, 57))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 52, 42))
    }
}

// Repro from #13995

declare function takeA(val: 'A'): void;
>takeA : Symbol(takeA, Decl(controlFlowGenericTypes.ts, 56, 1))
>val : Symbol(val, Decl(controlFlowGenericTypes.ts, 60, 23))

export function bounceAndTakeIfA<AB extends 'A' | 'B'>(value: AB): AB {
>bounceAndTakeIfA : Symbol(bounceAndTakeIfA, Decl(controlFlowGenericTypes.ts, 60, 39))
>AB : Symbol(AB, Decl(controlFlowGenericTypes.ts, 61, 33))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 61, 55))
>AB : Symbol(AB, Decl(controlFlowGenericTypes.ts, 61, 33))
>AB : Symbol(AB, Decl(controlFlowGenericTypes.ts, 61, 33))

    if (value === 'A') {
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 61, 55))

        takeA(value);
>takeA : Symbol(takeA, Decl(controlFlowGenericTypes.ts, 56, 1))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 61, 55))

        return value;
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 61, 55))
    }
    else {
        return value;
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 61, 55))
    }
}

// Repro from #13995

type Common = { id: number };
>Common : Symbol(Common, Decl(controlFlowGenericTypes.ts, 69, 1))
>id : Symbol(id, Decl(controlFlowGenericTypes.ts, 73, 15))

type AA = { tag: 'A', id: number };
>AA : Symbol(AA, Decl(controlFlowGenericTypes.ts, 73, 29))
>tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 74, 11))
>id : Symbol(id, Decl(controlFlowGenericTypes.ts, 74, 21))

type BB = { tag: 'B', id: number, foo: number };
>BB : Symbol(BB, Decl(controlFlowGenericTypes.ts, 74, 35))
>tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 75, 11))
>id : Symbol(id, Decl(controlFlowGenericTypes.ts, 75, 21))
>foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))

type MyUnion = AA | BB;
>MyUnion : Symbol(MyUnion, Decl(controlFlowGenericTypes.ts, 75, 48))
>AA : Symbol(AA, Decl(controlFlowGenericTypes.ts, 73, 29))
>BB : Symbol(BB, Decl(controlFlowGenericTypes.ts, 74, 35))

const fn = (value: MyUnion) => {
>fn : Symbol(fn, Decl(controlFlowGenericTypes.ts, 79, 5))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))
>MyUnion : Symbol(MyUnion, Decl(controlFlowGenericTypes.ts, 75, 48))

    value.foo;  // Error
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))

    if ('foo' in value) {
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))

        value.foo;
>value.foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))
>foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
    }
    if (value.tag === 'B') {
>value.tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 74, 11), Decl(controlFlowGenericTypes.ts, 75, 11))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))
>tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 74, 11), Decl(controlFlowGenericTypes.ts, 75, 11))

        value.foo;
>value.foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 79, 12))
>foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
    }
};

const fn2 = <T extends MyUnion>(value: T): MyUnion => {
>fn2 : Symbol(fn2, Decl(controlFlowGenericTypes.ts, 89, 5))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 89, 13))
>MyUnion : Symbol(MyUnion, Decl(controlFlowGenericTypes.ts, 75, 48))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 89, 13))
>MyUnion : Symbol(MyUnion, Decl(controlFlowGenericTypes.ts, 75, 48))

    value.foo;  // Error
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))

    if ('foo' in value) {
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))

        value.foo;
>value.foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))
>foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
    }
    if (value.tag === 'B') {
>value.tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 74, 11), Decl(controlFlowGenericTypes.ts, 75, 11))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))
>tag : Symbol(tag, Decl(controlFlowGenericTypes.ts, 74, 11), Decl(controlFlowGenericTypes.ts, 75, 11))

        value.foo;
>value.foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 89, 32))
>foo : Symbol(foo, Decl(controlFlowGenericTypes.ts, 75, 33))
    }
};

// Repro from #13995

type A1 = {
>A1 : Symbol(A1, Decl(controlFlowGenericTypes.ts, 97, 2))

    testable: true
>testable : Symbol(testable, Decl(controlFlowGenericTypes.ts, 101, 11))

    doTest: () => void
>doTest : Symbol(doTest, Decl(controlFlowGenericTypes.ts, 102, 18))
}
type B1 = {
>B1 : Symbol(B1, Decl(controlFlowGenericTypes.ts, 104, 1))

    testable: false
>testable : Symbol(testable, Decl(controlFlowGenericTypes.ts, 105, 11))

};

type Union = A1 | B1
>Union : Symbol(Union, Decl(controlFlowGenericTypes.ts, 107, 2))
>A1 : Symbol(A1, Decl(controlFlowGenericTypes.ts, 97, 2))
>B1 : Symbol(B1, Decl(controlFlowGenericTypes.ts, 104, 1))

function notWorking<T extends Union>(object: T) {
>notWorking : Symbol(notWorking, Decl(controlFlowGenericTypes.ts, 109, 20))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 111, 20))
>Union : Symbol(Union, Decl(controlFlowGenericTypes.ts, 107, 2))
>object : Symbol(object, Decl(controlFlowGenericTypes.ts, 111, 37))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 111, 20))

    if (!object.testable) return;
>object.testable : Symbol(testable, Decl(controlFlowGenericTypes.ts, 101, 11), Decl(controlFlowGenericTypes.ts, 105, 11))
>object : Symbol(object, Decl(controlFlowGenericTypes.ts, 111, 37))
>testable : Symbol(testable, Decl(controlFlowGenericTypes.ts, 101, 11), Decl(controlFlowGenericTypes.ts, 105, 11))

    object.doTest();
>object.doTest : Symbol(doTest, Decl(controlFlowGenericTypes.ts, 102, 18))
>object : Symbol(object, Decl(controlFlowGenericTypes.ts, 111, 37))
>doTest : Symbol(doTest, Decl(controlFlowGenericTypes.ts, 102, 18))
}

// Repro from #42939

interface A {
>A : Symbol(A, Decl(controlFlowGenericTypes.ts, 114, 1))

    a: number | null;
>a : Symbol(A.a, Decl(controlFlowGenericTypes.ts, 118, 13))

};

function get<K extends keyof A>(key: K, obj: A): number {
>get : Symbol(get, Decl(controlFlowGenericTypes.ts, 120, 2))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 122, 13))
>A : Symbol(A, Decl(controlFlowGenericTypes.ts, 114, 1))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 122, 32))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 122, 13))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 122, 39))
>A : Symbol(A, Decl(controlFlowGenericTypes.ts, 114, 1))

    const value = obj[key];
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 123, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 122, 39))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 122, 32))

    if (value !== null) {
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 123, 9))

        return value;
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 123, 9))
    }
    return 0;
};

// Repro from #44093

class EventEmitter<ET> {
>EventEmitter : Symbol(EventEmitter, Decl(controlFlowGenericTypes.ts, 128, 2))
>ET : Symbol(ET, Decl(controlFlowGenericTypes.ts, 132, 19))

    off<K extends keyof ET>(...args: [K, number] | [unknown, string]):void {}
>off : Symbol(EventEmitter.off, Decl(controlFlowGenericTypes.ts, 132, 24))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 133, 8))
>ET : Symbol(ET, Decl(controlFlowGenericTypes.ts, 132, 19))
>args : Symbol(args, Decl(controlFlowGenericTypes.ts, 133, 28))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 133, 8))
}
function once<ET, T extends EventEmitter<ET>>(emittingObject: T, eventName: keyof ET): void {
>once : Symbol(once, Decl(controlFlowGenericTypes.ts, 134, 1))
>ET : Symbol(ET, Decl(controlFlowGenericTypes.ts, 135, 14))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 135, 17))
>EventEmitter : Symbol(EventEmitter, Decl(controlFlowGenericTypes.ts, 128, 2))
>ET : Symbol(ET, Decl(controlFlowGenericTypes.ts, 135, 14))
>emittingObject : Symbol(emittingObject, Decl(controlFlowGenericTypes.ts, 135, 46))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 135, 17))
>eventName : Symbol(eventName, Decl(controlFlowGenericTypes.ts, 135, 64))
>ET : Symbol(ET, Decl(controlFlowGenericTypes.ts, 135, 14))

    emittingObject.off(eventName, 0);
>emittingObject.off : Symbol(EventEmitter.off, Decl(controlFlowGenericTypes.ts, 132, 24))
>emittingObject : Symbol(emittingObject, Decl(controlFlowGenericTypes.ts, 135, 46))
>off : Symbol(EventEmitter.off, Decl(controlFlowGenericTypes.ts, 132, 24))
>eventName : Symbol(eventName, Decl(controlFlowGenericTypes.ts, 135, 64))

    emittingObject.off(eventName as typeof eventName, 0);
>emittingObject.off : Symbol(EventEmitter.off, Decl(controlFlowGenericTypes.ts, 132, 24))
>emittingObject : Symbol(emittingObject, Decl(controlFlowGenericTypes.ts, 135, 46))
>off : Symbol(EventEmitter.off, Decl(controlFlowGenericTypes.ts, 132, 24))
>eventName : Symbol(eventName, Decl(controlFlowGenericTypes.ts, 135, 64))
>eventName : Symbol(eventName, Decl(controlFlowGenericTypes.ts, 135, 64))
}

// In an element access obj[x], we consider obj to be in a constraint position, except when obj is of
// a generic type without a nullable constraint and x is a generic type. This is because when both obj
// and x are of generic types T and K, we want the resulting type to be T[K].

function fx1<T, K extends keyof T>(obj: T, key: K) {
>fx1 : Symbol(fx1, Decl(controlFlowGenericTypes.ts, 138, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 144, 13))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 144, 15))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 144, 13))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 144, 35))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 144, 13))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 144, 42))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 144, 15))

    const x1 = obj[key];
>x1 : Symbol(x1, Decl(controlFlowGenericTypes.ts, 145, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 144, 35))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 144, 42))

    const x2 = obj && obj[key];
>x2 : Symbol(x2, Decl(controlFlowGenericTypes.ts, 146, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 144, 35))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 144, 35))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 144, 42))
}

function fx2<T extends Record<keyof T, string>, K extends keyof T>(obj: T, key: K) {
>fx2 : Symbol(fx2, Decl(controlFlowGenericTypes.ts, 147, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 149, 13))
>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 149, 13))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 149, 47))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 149, 13))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 149, 67))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 149, 13))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 149, 74))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 149, 47))

    const x1 = obj[key];
>x1 : Symbol(x1, Decl(controlFlowGenericTypes.ts, 150, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 149, 67))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 149, 74))

    const x2 = obj && obj[key];
>x2 : Symbol(x2, Decl(controlFlowGenericTypes.ts, 151, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 149, 67))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 149, 67))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 149, 74))
}

function fx3<T extends Record<keyof T, string> | undefined, K extends keyof T>(obj: T, key: K) {
>fx3 : Symbol(fx3, Decl(controlFlowGenericTypes.ts, 152, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 154, 13))
>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 154, 13))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 154, 59))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 154, 13))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 154, 79))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 154, 13))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 154, 86))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 154, 59))

    const x1 = obj[key];  // Error
>x1 : Symbol(x1, Decl(controlFlowGenericTypes.ts, 155, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 154, 79))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 154, 86))

    const x2 = obj && obj[key];
>x2 : Symbol(x2, Decl(controlFlowGenericTypes.ts, 156, 9))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 154, 79))
>obj : Symbol(obj, Decl(controlFlowGenericTypes.ts, 154, 79))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 154, 86))
}

// Repro from #44166

class TableBaseEnum<
>TableBaseEnum : Symbol(TableBaseEnum, Decl(controlFlowGenericTypes.ts, 157, 1))

    PublicSpec extends Record<keyof InternalSpec, any>,
>PublicSpec : Symbol(PublicSpec, Decl(controlFlowGenericTypes.ts, 161, 20))
>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
>InternalSpec : Symbol(InternalSpec, Decl(controlFlowGenericTypes.ts, 162, 55))

    InternalSpec extends Record<keyof PublicSpec, any>  | undefined = undefined> {
>InternalSpec : Symbol(InternalSpec, Decl(controlFlowGenericTypes.ts, 162, 55))
>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
>PublicSpec : Symbol(PublicSpec, Decl(controlFlowGenericTypes.ts, 161, 20))

    m() {
>m : Symbol(TableBaseEnum.m, Decl(controlFlowGenericTypes.ts, 163, 82))

        let iSpec = null! as InternalSpec;
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>InternalSpec : Symbol(InternalSpec, Decl(controlFlowGenericTypes.ts, 162, 55))

        iSpec[null! as keyof InternalSpec];  // Error, object possibly undefined
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>InternalSpec : Symbol(InternalSpec, Decl(controlFlowGenericTypes.ts, 162, 55))

        iSpec[null! as keyof PublicSpec];    // Error, object possibly undefined
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>PublicSpec : Symbol(PublicSpec, Decl(controlFlowGenericTypes.ts, 161, 20))

        if (iSpec === undefined) {
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>undefined : Symbol(undefined)

            return;
        }
        iSpec[null! as keyof InternalSpec];
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>InternalSpec : Symbol(InternalSpec, Decl(controlFlowGenericTypes.ts, 162, 55))

        iSpec[null! as keyof PublicSpec];
>iSpec : Symbol(iSpec, Decl(controlFlowGenericTypes.ts, 165, 11))
>PublicSpec : Symbol(PublicSpec, Decl(controlFlowGenericTypes.ts, 161, 20))
    }
}

// Repros from #45145

function f10<T extends { a: string } | undefined>(x: T, y: Partial<T>) {
>f10 : Symbol(f10, Decl(controlFlowGenericTypes.ts, 174, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 178, 13))
>a : Symbol(a, Decl(controlFlowGenericTypes.ts, 178, 24))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 178, 50))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 178, 13))
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 178, 55))
>Partial : Symbol(Partial, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 178, 13))

    y = x;
>y : Symbol(y, Decl(controlFlowGenericTypes.ts, 178, 55))
>x : Symbol(x, Decl(controlFlowGenericTypes.ts, 178, 50))
}

type SqlInsertSet<T> = T extends undefined ? object : { [P in keyof T]: unknown };
>SqlInsertSet : Symbol(SqlInsertSet, Decl(controlFlowGenericTypes.ts, 180, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 182, 18))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 182, 18))
>P : Symbol(P, Decl(controlFlowGenericTypes.ts, 182, 57))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 182, 18))

class SqlTable<T> {
>SqlTable : Symbol(SqlTable, Decl(controlFlowGenericTypes.ts, 182, 82))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 184, 15))

    protected validateRow(_row: Partial<SqlInsertSet<T>>): void {
>validateRow : Symbol(SqlTable.validateRow, Decl(controlFlowGenericTypes.ts, 184, 19))
>_row : Symbol(_row, Decl(controlFlowGenericTypes.ts, 185, 26))
>Partial : Symbol(Partial, Decl(lib.es5.d.ts, --, --))
>SqlInsertSet : Symbol(SqlInsertSet, Decl(controlFlowGenericTypes.ts, 180, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 184, 15))
    }
    public insertRow(row: SqlInsertSet<T>) {
>insertRow : Symbol(SqlTable.insertRow, Decl(controlFlowGenericTypes.ts, 186, 5))
>row : Symbol(row, Decl(controlFlowGenericTypes.ts, 187, 21))
>SqlInsertSet : Symbol(SqlInsertSet, Decl(controlFlowGenericTypes.ts, 180, 1))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 184, 15))

        this.validateRow(row);
>this.validateRow : Symbol(SqlTable.validateRow, Decl(controlFlowGenericTypes.ts, 184, 19))
>this : Symbol(SqlTable, Decl(controlFlowGenericTypes.ts, 182, 82))
>validateRow : Symbol(SqlTable.validateRow, Decl(controlFlowGenericTypes.ts, 184, 19))
>row : Symbol(row, Decl(controlFlowGenericTypes.ts, 187, 21))
    }
}

// Repro from #46495

interface Button {
>Button : Symbol(Button, Decl(controlFlowGenericTypes.ts, 190, 1))

    type: "button";
>type : Symbol(Button.type, Decl(controlFlowGenericTypes.ts, 194, 18))

    text: string;
>text : Symbol(Button.text, Decl(controlFlowGenericTypes.ts, 195, 19))
}

interface Checkbox {
>Checkbox : Symbol(Checkbox, Decl(controlFlowGenericTypes.ts, 197, 1))

    type: "checkbox";
>type : Symbol(Checkbox.type, Decl(controlFlowGenericTypes.ts, 199, 20))

    isChecked: boolean;
>isChecked : Symbol(Checkbox.isChecked, Decl(controlFlowGenericTypes.ts, 200, 21))
}

type Control = Button | Checkbox;
>Control : Symbol(Control, Decl(controlFlowGenericTypes.ts, 202, 1))
>Button : Symbol(Button, Decl(controlFlowGenericTypes.ts, 190, 1))
>Checkbox : Symbol(Checkbox, Decl(controlFlowGenericTypes.ts, 197, 1))

function update<T extends Control, K extends keyof T>(control : T | undefined, key: K, value: T[K]): void {
>update : Symbol(update, Decl(controlFlowGenericTypes.ts, 204, 33))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 206, 16))
>Control : Symbol(Control, Decl(controlFlowGenericTypes.ts, 202, 1))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 206, 34))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 206, 16))
>control : Symbol(control, Decl(controlFlowGenericTypes.ts, 206, 54))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 206, 16))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 206, 78))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 206, 34))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 206, 86))
>T : Symbol(T, Decl(controlFlowGenericTypes.ts, 206, 16))
>K : Symbol(K, Decl(controlFlowGenericTypes.ts, 206, 34))

    if (control !== undefined) {
>control : Symbol(control, Decl(controlFlowGenericTypes.ts, 206, 54))
>undefined : Symbol(undefined)

        control[key] = value;
>control : Symbol(control, Decl(controlFlowGenericTypes.ts, 206, 54))
>key : Symbol(key, Decl(controlFlowGenericTypes.ts, 206, 78))
>value : Symbol(value, Decl(controlFlowGenericTypes.ts, 206, 86))
    }
}