Improve support of property existance checking
- Dominant language
- Rust
- Stars
- 22.3k
- Forks
- 1.9k
- PR merge metrics
- No merged PRs in 30d
Description
Flow version: ALL
## Expected behavior
- `if (prop in obj) console.log(obj[prop])` should work
- `if (typeof obj[prop] !== "undefined") console.log(obj[prop])` should work
- `if (obj[prop] !== undefined) console.log(obj[prop])` should work
- `if (obj[prop]) console.log(obj[prop])` should work
## Actual behavior
There is no way to check if a property exist without getting an error
* Link to Try-Flow or Github repo: [Try Flow](https://flow.org/try/#0MYewdgzgLgBATgUwI4FcHQMpQIZRRdGAXhgG8AoGGASwBMAbBALhgAoAiOx9lzhhdgEoANJRgAzbNUa0WHSdIS0eMdgplDRVCCmDAESuex16Dy3if1Kh5AL4BucuSgBPAA4IYAJWRpMOPAhiGAASADVsej8AHlcPEHF4X3QoLFx8dAA+exgnUEhYAFt0CGwAc0ISCioAbURUFLTA9AA6dSUAXV4fBugYAAtsIPblLRg65P90gggWyzMu1R6-WEGg+etRBzzwPvqVpvwWZcaA-GDWFDBaBHFqMEMYbDAXQUdyakTWfdPpmjAYMUIKUKhBBGQxPkICBGC16CAyqwgSD0BNeqkzhAOm87E5Pmw4ggEoCSuVUT8poEOjAAIREEjsK43O4PZTg6owKEwhBwhFI0mgtEHTHYxy2PFfZFkiBC35U2n0mBM273JTsyG7bm8xFSwUUjHTUW4j6SgXkyYGqnqqhc2HwnVmmX6w5YnG2IA)
Contributor guide
Assessment
This issue has not been assessed yet.