Plugin
legacy-code
Working effectively with legacy code (Michael Feathers) applied pragmatically, in two skills: the method (legacy code is code without tests, the Legacy Code Change Algorithm, seams and enabling points, characterization tests, reasoning about effects) and the dependency-breaking catalogue (Sprout, Wrap, Extract Interface, Subclass and Override, Parameterize Constructor, Extract and Override Factory, and the rest), with TypeScript specifics. Composable with your own conventions.