Production builds

Diagnostic catalogs contain user-facing text. That text is useful during development, but you often do not want report-only diagnostics in a production bundle.

nosticsStrip is a build-time plugin for that.

Setup

Vite:

import { nosticsStrip } from 'nostics/unplugin/strip-transform'
import { defineConfig } from 'vite'

export default defineConfig({
  plugins: [nosticsStrip.vite()],
})

Rolldown through tsdown:

import { nosticsStrip } from 'nostics/unplugin/strip-transform'
import { defineConfig } from 'tsdown'

export default defineConfig({
  entry: ['src/index.ts'],
  plugins: [nosticsStrip.rolldown()],
})

The plugin is built with unplugin, so it also exposes .rollup(), .webpack(), .rspack(), .esbuild(), and .farm().

What it changes

First, it marks defineDiagnostics() calls as pure.

const diagnostics = /*#__PURE__*/ defineDiagnostics({
  codes: {
    NUXT_B2011: { why: 'Plugin mode conflicts with file suffix.' },
  },
})

Second, it wraps bare diagnostic expression statements with a production guard.

diagnostics.NUXT_B2011()

becomes:

process.env.NODE_ENV !== "production" && diagnostics.NUXT_B2011()

In a production build, bundlers can remove the call. Once the calls are gone, the diagnostic catalog usually becomes unused too.

What stays

The plugin only strips report-only expression statements.

These can be stripped:

diagnostics.NUXT_B2011()
condition && diagnostics.NUXT_B5001()

These stay:

throw diagnostics.NUXT_B2011()
return diagnostics.NUXT_B2011()
const diagnostic = diagnostics.NUXT_B2011()
fn(diagnostics.NUXT_B2011())

This matters. Throwing a diagnostic is part of your runtime behavior, so the plugin leaves it alone.

Cross-file tracking

The plugin can track a directly exported diagnostics object across one relative import.

export const diagnostics = defineDiagnostics({
  codes: {
    NUXT_B2011: { why: 'Plugin mode conflicts with file suffix.' },
  },
})

import { diagnostics } from './diagnostics'

diagnostics.NUXT_B2011()

Keep this simple for best results:

• Use relative imports.
• Export the result of defineDiagnostics() directly.
• Avoid factory wrappers for exported diagnostics objects.
• Avoid relying on deep barrel re-exports for stripping.

Options

nosticsStrip.vite({
  packageName: 'my-diagnostics-wrapper',
})

Check the output

After a production build, search the bundle:

rg 'NUXT_B2011|Plugin mode conflicts' dist/

Report-only diagnostics should be gone. Diagnostics used in throw, return, assignments, or function arguments can remain.