Use "extends" in tsconfig.json

[karlhorky]

To simplify the config file tsconfig.json, we can use the "extends" key to refer to a base configuration file.

Example: expo/expo#11680

[karlhorky]

Unfortunately, we need to use these brittle relative paths in our configuration:

eslint-config-upleveled/tsconfig.base.json

Lines 24 to 34 in 8934a1f

	"include": [
	"../../../**/.eslintrc.cjs",
	"../../../next-env.d.ts",
	"../../../**/*.ts",
	"../../../**/*.tsx",
	"../../../**/*.js",
	"../../../**/*.jsx",
	"../../../**/*.cjs",
	"../../../**/*.mjs"
	],
	"exclude": ["../../../node_modules", "../../../build"]

That's because TypeScript doesn't have an easy way to refer to the "root directory" from an "extends" config, asked about that here:

• tsconfig.json: Specify <root> in "include" and "exclude" for extends configs microsoft/TypeScript#51213