Function toRelative

packages/vite/src/node/plugins/css.ts:719–727

(filename: string)

                  : undefined

              const toRelative = (filename: string) => {
                // relative base + extracted CSS
                const relativePath = normalizePath(
                  path.relative(cssAssetDirname!, filename),
                )
                return relativePath[0] === '.'
                  ? relativePath
                  : './' + relativePath
              }

              // replace asset url references with resolved url.
              chunkCSS = chunkCSS.replace(