overrides doesn't override but extends default arrays and objects

[tmlmt]

Environment

• node: v18.18.0
• c12: v1.5.1

Reproduction

https://stackblitz.com/edit/stackblitz-starters-13rkzj?file=index.js

Describe the bug

The use of defu to merge sources in

c12/src/loader.ts

Lines 112 to 119 in 54ed82b

	// Combine sources
	r.config = defu(
	options.overrides,
	config,
	configRC,
	pkgJson,
	options.defaultConfig,
	) as T;

makes it such that a default array (or object) is not overridden but extended by the array (or object) given in override.

Is this the intended behavior?

Additional context

If one wants to provide a default list customizable by the user, it forces one to flatten the list in a string.

Logs

No response