From npm scripts or Vite Task

The Turbo and Nx paths have their
own posts. Two more starting points convert just as directly: plain
package.json scripts and Vite Task.

npm scripts, hooks included

npm runs prebuild before build and postbuild after it, without
being asked. Copying the scripts one to one would lose that. So
vx init folds the hooks into the task's command, in npm's order, and
says so:

$ cat packages/app/package.json
{"name":"app","scripts":{"prebuild":"rimraf dist","build":"tsc","postbuild":"node scripts/copy.js"}}

$ vx init --dry
vx init: package.json scripts → vx.config.ts
note: each script became a task with its command verbatim; caching needs declared inputs and outputs, so no task got a cache block

0 tasks migrated clean, 2 TODOs:
  app#build: npm ran `prebuild` and `postbuild` around this script without being asked; folded into the command in that order
  app#build: cache: add `cache: { inputs: { files: ['src/**'] }, outputs: { files: ['dist/**'] } }` with this package's real inputs and outputs …

Each part runs in its own subshell, so the chain stops at the first
that fails, and arguments after -- reach build alone, as npm passes
them. Where the package manager runs no such hooks (Yarn 2 and later, or
npm with ignore-scripts), each hook stays a task of its own. Lifecycle
hooks like prepack never become tasks.

Vite Task

A repo on vite-plus keeps its tasks in each package's vite.config.*
under run. The migrator reads them the way vp run does:

$ bunx @vzn/vx-migrate --from vite-task

command, cwd, dependsOn and the cache settings map to their vx
spellings. A command that starts with vp run x becomes a dependsOn
edge, the way Vite Task inlines it. Anything that does not map cleanly
stays in the command with a TODO, so nothing is dropped without a word.

The full mapping table is in the
vx-migrate README.

---

Originally published on the vx blog. vx is an MIT task runner and build cache for JS monorepos: vznjs.github.io/vx · GitHub.

_{Written with AI assistance.}