Some of these missing checks were why Flow was an attractive choice when weighing [Flow vs Typescript][1]. For example, it wasn't until Typescript 2.0 that we

Some of these missing checks were why Flow was an attractive choice when weighing [Flow vs Typescript][1]. For example, it wasn't until Typescript 2.0 that we got null checks! - https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-0.html#null--and-undefined-aware-types https://www.typescriptlang.org/docs/handbook/release-notes/t... function getLength(s: string): number { return s.length; // Runtime crash if s is null/undefined } getLength(null); // TypeScript <2.0 would not error here [1]: https://djcordhose.github.io/flow-vs-typescript/2016_hhjs.html#/15 https://djcordhose.github.io/flow-vs-typescript/2016_hhjs.ht...