This plugin automatically adds @types/ packages into your dependencies when you add a package that doesn't include its own types.
yarn plugin import typescript
❯ yarn/packages/plugin-typescript ❯ yarn add lodash
➤ BR0000: ┌ Resolution step
➤ BR0002: │ babel-preset-jest@npm:24.1.0 doesn't provide @babel/core@^7.0.0-0 requested by @babel/plugin-syntax-object-rest-spread@npm:7.2.0
➤ BR0000: └ Completed in 0.24s
➤ BR0000: ┌ Fetch step
➤ BR0013: │ @types/lodash@npm:4.14.121 can't be found in the cache and will be fetched from the remote registry
➤ BR0000: └ Completed in 3.63s
➤ BR0000: ┌ Link step
➤ BR0005: │ webpack-cli@npm:3.2.1 lists build scripts, but its build has been explicitly disabled through configuration.
➤ BR0005: │ fsevents@npm:1.2.6 lists build scripts, but its build has been explicitly disabled through configuration.
➤ BR0005: │ webpack-cli@npm:3.2.1 lists build scripts, but its build has been explicitly disabled through configuration.
➤ BR0005: │ webpack-cli@npm:3.2.1 lists build scripts, but its build has been explicitly disabled through configuration.
➤ BR0000: └ Completed in 2.75s
➤ BR0000: Done with warnings in 6.81s
As you can see in the fetch step, even though we only added lodash into our dependencies, Yarn automatically figured out that we would need @types/lodash, and added it before we ask it to.