eslint-svelte3-preprocess/dist-src/preprocess.js

svelte preprocess for eslint-plugin-svelte3

import esTree from "@typescript-eslint/typescript-estree";
import svelteCompiler from "svelte/compiler";
export const preprocess = async (src, filename, preprocessors) => {
    let markup;
    let module;
    let instance;
    let style;
    const result = await svelteCompiler.preprocess(src, [
        {
            markup: ({ content }) => {
                markup = {
                    original: content,
                };
                return {
                    code: content,
                };
            },
            script: ({ content, attributes }) => {
                // Supported scenarios
                // type="text/typescript"
                // lang="typescript"
                // lang="ts"
                if (attributes.lang === "ts" ||
                    attributes.lang === "typescript" ||
                    attributes.type === "text/typescript") {
                    const ast = esTree.parse(content, { loc: true });
                    const obj = {
                        ast,
                        original: content,
                        ext: "ts",
                    };
                    if (attributes.context) {
                        module = obj;
                    }
                    else {
                        instance = obj;
                    }
                }
                return {
                    code: content,
                };
            },
            style: ({ content }) => {
                style = {
                    original: content,
                };
                return {
                    code: content,
                };
            },
        },
        ...(Array.isArray(preprocessors) ? preprocessors : [preprocessors]),
        {
            markup: ({ content }) => {
                if (markup) {
                    markup.result = content;
                    markup.diff = markup.original.length - content.length;
                }
                return {
                    code: content,
                };
            },
            script: ({ content, attributes }) => {
                const obj = attributes.context ? module : instance;
                if (obj) {
                    obj.result = content;
                    obj.diff = obj.original.length - content.length;
                }
                return {
                    code: content,
                };
            },
            style: ({ content }) => {
                if (style) {
                    style.result = content;
                    style.diff = style.original.length - content.length;
                }
                return {
                    code: content,
                };
            },
        },
    ], { filename: filename || "unknown" });
    return {
        ...result,
        instance,
        markup,
        module,
        style,
    };
};