svelte-sequential-preprocessor

A Svelte preprocessor that wraps preprocessors to force them to be called sequentially.

Overview

Svelte evaluates preprocessors by running all markup preprocessors first, then script and finally styles. Some preprocesses may not work if other preprocessors haven't been run. For example, svelte-image uses svelte.parse() internally, so svelte-preprocess needs to be run before if any scss is present.

Installation

Using npm:

$ npm i -D svelte-sequential-preprocessor

Usage

With rollup-plugin-svelte

// rollup.config.js
import svelte from 'rollup-plugin-svelte';
import seqPreprocessor from 'svelte-sequential-preprocessor'
import autoPreprocess from 'svelte-preprocess'
import image from 'svelte-image'

export default {
  ...,
  plugins: [
    svelte({
      preprocess: seqPreprocessor([ autoPreprocess(), image() ])
    })
  ]
}

With svelte-loader

  ...
  module: {
    rules: [
      ...
      {
        test: /\.(html|svelte)$/,
        exclude: /node_modules/,
        use: {
          loader: 'svelte-loader',
          options: {
            preprocess: require('svelte-sequential-preprocessor')([ require('svelte-preprocess'), require('svelte-image')])
          },
        },
      },
      ...
    ]
  }
  ...

With SvelteKit

// svelte.config.js
import adapter from '@sveltejs/adapter-auto';
import seqPreprocessor from 'svelte-sequential-preprocessor';
import autoPreprocess from 'svelte-preprocess';
import image from 'svelte-image';

/** @type {import('@sveltejs/kit').Config} */
const config = {
  preprocess: seqPreprocessor([autoPreprocess(), image()]),

  kit: {
    adapter: adapter()
  }
};

export default config;