This takes JSDuck output (https://github.com/senchalabs/jsduck) and turns it into type declarations for Typescript (version 1.4+).
This is designed to be used in conjunction with fabioparra's patched Typescript compiler that emits ExtJS style classes (https://github.com/fabioparra/TypeScript). ExtJS versions 4 and 5 are supported.
There is a selection of pre-generated declarations files (for ExtJS 4 and 5) in the declarations folder. Make an issue if you would like to see another one, or generate it yourself (see below).
The easiest way to do this is probably to modify generate-defaults.ts and add another entry to the EXT_VERSIONS array. You can then run npm install to run the script.