ts-loader goes webpack 4... again!

Back in 2021 I published a post called ts-loader goes webpack 5; a big exciting post about how ts-loader was upgraded to directly support webpack 5, and drop support for webpack 4 in v9 of ts-loader. For reasons which I'll get into shortly, as of v9.6.0, ts-loader now supports both webpack 5 (as it did already) and webpack 4. So if you're a webpack 4 user, you can now use ts-loader@9, rather than using ts-loader@8. Why support webpack 4 again?​ It is 2026. ts-loader@9 was released in 2021. I made the (bold) decision then to drop support for webpack 4 there and then. I would maintain webpack 4 branch in ts-loader so I could make any patches that might be necessary over time. At the time this seemed reasonable; webpack had been evolving quickly. I remember the path from webpack 1 to webpack 4 being pretty swift and figured that would continue. However, five years have passed and webpack 5 is the latest version of webpack still. (That may change.) After webpack 5 shipping, it took people…