Why does the default tsconfig.ts file have rootDir: '.' ?

[tylerlong]

compilerOptions: {rootDir: '.', outDir: 'build'},

https://github.com/google/gts/blob/master/src/init.ts#L239

The config file should be minimal. It should not contain configurations which are not necessary.

Every time I run gts init, I need to manually remove rootDir: '.' because it doesn't make sense to my project.