1. I m trying to get ckeditor with html support to work within svelte.

<script>
    import { onMount } from  svelte ;
    import ClassicEditor from  @ckeditor/ckeditor5-build-classic ;
    import { FullPage } from  @ckeditor/ckeditor5-html-support ;
    export let text = ""; 
    onMount( () => {
        ClassicEditor.create( document.querySelector(  #editor  ), {plugins : [FullPage]})
        .then( editor => {
            console.log( editor );
            editor.setData( text );
            editor.model.document.on(  change:data , () => {
                text = editor.getData();
            } );
        } )
        .catch( error => {
            console.error( error );
        } );
    });
</script>

<textarea id= editor ></textarea>

✔️ Expected result

I would expect the above code to result in a ckeditor instance with html support.

❌ Actual result

my js build using rollup gives me the below error

(!) Circular dependencies
node_modules/@ckeditor/ckeditor5-engine/src/view/position.js -> node_modules/@ckeditor/ckeditor5-engine/src/view/treewalker.js -> node_modules/@ckeditor/ckeditor5-engine/src/view/position.js
node_modules/@ckeditor/ckeditor5-engine/src/view/documentselection.js -> node_modules/@ckeditor/ckeditor5-engine/src/view/selection.js -> node_modules/@ckeditor/ckeditor5-engine/src/view/documentselection.js
node_modules/@ckeditor/ckeditor5-engine/src/model/position.js -> node_modules/@ckeditor/ckeditor5-engine/src/model/treewalker.js -> node_modules/@ckeditor/ckeditor5-engine/src/model/position.js
...and 4 more
created static/js/bundle.js in 13.7s

❓ Possible solution

If I remove the line as well as FullPage from the plugins array then I have no issues.

import { FullPage } from  @ckeditor/ckeditor5-html-support ;

The editor will be instantiated. this could be an issue with my rollup.config.js --

import svelte from  rollup-plugin-svelte ;
import resolve from  @rollup/plugin-node-resolve ;
import commonjs from  @rollup/plugin-commonjs ;
import livereload from  rollup-plugin-livereload ;
import { terser } from  rollup-plugin-terser ;
import css from "rollup-plugin-css-only";
import autoPreprocess from  svelte-preprocess ;
import copy from  rollup-plugin-copy ;
import scss from  rollup-plugin-scss ;
import polyfillNode from  rollup-plugin-polyfill-node ;
import svg from  rollup-plugin-svg ;

const production = !process.env.ROLLUP_WATCH;
export default {
    input:  svelte-components/src/main.js , // (1)
    output: {
        sourcemap: true,
        format:  iife ,
        name:  app ,
        file:  static/js/bundle.js 
    },
    plugins: [
        svg(),
        css({ output: "extra_bundle.css" }),
        scss({
            fileName: "bootstrap.css",
            failOnError: true,
            runtime: require("sass"),
          }),
        svelte({
            // enable run-time checks when not in production
            dev: !production,
            // we ll extract any component CSS out into
            // a separate file - better for performance
            css: css => {
                css.write( bundle.css ); // (3)
            }
        }),
        // If you have external dependencies installed from
        // npm, you ll most likely need these plugins. In
        // some cases you ll need additional configuration -
        // consult the documentation for details:
        // https://github.com/rollup/plugins/tree/master/packages/commonjs
        resolve({
            browser: true,
            dedupe: [ svelte ]
        }),
        commonjs(),
        // In dev mode, call `npm run start` once
        // the bundle has been generated
        !production && serve(),

        // Watch the `public` directory and refresh the
        // browser on changes when not in production
        !production && livereload( svelte-components ), // (4)

        // If we re building for production (npm run build
        // instead of npm run dev), minify
        production && terser(),
        copy({
            targets: [
                { src:  node_modules/bootstrap/dist/js/bootstrap.min.js , dest:  static/js  },              
            ],
            verbose: true,
        }),
        polyfillNode(), // Add this plugin
        terser()
    ],
    watch: { 
        clearScreen: false
    }
};

function serve() {
    let started = false;

    return {
        writeBundle() {
            if (!started) {
                started = true;

                require( child_process ).spawn( npm , [ run ,  start ,  -- ,  --dev ], {
                    stdio: [ ignore ,  inherit ,  inherit ],
                    shell: true
                });
            }
        }
    };
}

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