Type inference only works on the same line as the variable declaration

I ran into this odd behavior while writing some tests, that do the typical `describe`, declare a closure-scope variable, and in `beforeEach`, assign some object to that variable that is used in each of the tests inside. **Search Terms:** infer, inference, closure, scope, broken, any, cast Initially, I thought it was limited to closure scope, but I then started reducing the reproduction sample more and more, and realized, it's broken even if it's on the very next line: **Code** ```ts // given interface Foo { id: string; } function make(): Foo { return { id: 'akatechis', } } // u1 is correctly inferred to be of type Foo. let u1 = make(); // u2 is incorrectly inferred to be of type any. let u2; u2 = make(); // this was the scenario in which I originally ran into this: // a closure scoped variable that is assigned in an inner function function outer () { // u3 is inferred to be of type any let u3; return { inner() { // u3 here is still any u3 = make(); // surprisingly, returning u3 here causes the return type of inner() to be Foo, not any??? return u3; } } } ``` **Expected type declarations:** ```ts interface Foo { id: string; } declare function make(): Foo; declare let u1: Foo; declare let u2: Foo; // <---- this should have been inferred to be Foo declare function outer(): { inner(): Foo; }; ``` **Actual type declarations:** ```ts interface Foo { id: string; } declare function make(): Foo; declare let u1: Foo; declare let u2: any; declare function outer(): { inner(): Foo; }; ``` **Playground Link:** [playground](https://www.typescriptlang.org/play?ts=4.1.0-dev.20201027#code/PTAEHMEsDcFMDsBQl4BdYCcBmBDAxrKAGID2JoA3oqDaJACYBcoAzqhiuANyIC+iiLAFd4eVJBLxQAWxwBrWAAoAlM1LkqtUBliohGKZq20GzAOTyc6PAAtILMwBpqtfv0QhQQgIx0WoPBIMHTEAGwBPOngsTB16UFRyACNCEiwE8IAHQnUAOkRQ3S9fAF4ZeSVlHg8wIQAmPyjA4NgwyJQYlvjE0BTQNIzs0Bx4cPzC1C86nnrQMtkFFWrhUXFJfqF0DFAVShcaTyEAZkaO2Nhu5NT01C…