These are a collection of tools that we used at Quizlet when migrating from Flow to TypeScript. We hope that you find these tools useful when doing your own migration, but keep in mind that they are made for the particularities of Quizlet's large codebase. You may need to modify these tools to suit your needs, but that said, they should be at the very least a good starting point.
The converter uses a fork of babel-plugin-flow-to-typescript along with Recast to preserve formatting. As it runs, it will rename files to .ts (or .tsx if it contains React), along with any snaps. In order to preserve the git history, this runs the conversion and commits the changes, and then renames all the files in a separate commit.
yarn add --dev quizlet/ts-migration.git[#commit]
- TypeScript is installed in your codebase, and you have a
tsconfig.jsonconfigured to suit your needs. - You use prettier, and you have a
.prettierrc.
Once installed, you can access the tools via the binary.
yarn ts-migration convert-codebase
yarn ts-migration convert-codebase --commit
yarn ts-migration ignore-errors [--commit] [--includeJSX]
The --includeJSX option can be extremely useful when you have a lot of errors you want to ignore, but will insert ignore comments in such a way that they can appear in the rendered HTML, so be sure to carefully review the output!
yarn ts-migration strip-comments [--commit]
ts-migration is MIT licensed.