svelte-eslint-parser/lib/parser/style-context.js

Svelte parser for ESLint

import postcss from "postcss";
import { parse as SCSSparse } from "postcss-scss";
import { default as selectorParser, } from "postcss-selector-parser";
/**
 * Extracts style source from a SvelteStyleElement and parses it into a PostCSS AST.
 */
export function parseStyleContext(styleElement, ctx) {
    if (!styleElement || !styleElement.endTag) {
        return { status: "no-style-element" };
    }
    let sourceLang = "css";
    for (const attribute of styleElement.startTag.attributes) {
        if (attribute.type === "SvelteAttribute" &&
            attribute.key.name === "lang" &&
            attribute.value.length > 0 &&
            attribute.value[0].type === "SvelteLiteral") {
            sourceLang = attribute.value[0].value;
        }
    }
    let parseFn, sourceAst;
    switch (sourceLang) {
        case "css":
        case "postcss":
            parseFn = postcss.parse;
            break;
        case "scss":
            parseFn = SCSSparse;
            break;
        default:
            return { status: "unknown-lang", sourceLang };
    }
    const styleCode = ctx.code.slice(styleElement.startTag.range[1], styleElement.endTag.range[0]);
    try {
        sourceAst = parseFn(styleCode, {
            from: ctx.parserOptions.filePath,
        });
    }
    catch (error) {
        return { status: "parse-error", sourceLang, error: error };
    }
    fixPostCSSNodeLocation(sourceAst, styleElement);
    sourceAst.walk((node) => {
        fixPostCSSNodeLocation(node, styleElement);
    });
    return { status: "success", sourceLang, sourceAst };
}
/**
 * Parses a PostCSS Rule node's selector and returns its AST.
 */
export function parseSelector(rule) {
    const processor = selectorParser();
    const root = processor.astSync(rule.selector);
    fixSelectorNodeLocation(root, rule);
    root.walk((node) => {
        fixSelectorNodeLocation(node, rule);
    });
    return root;
}
/**
 * Extracts a node location (like that of any ESLint node) from a parsed svelte style node.
 */
export function styleNodeLoc(node) {
    if (node.source === undefined) {
        return {};
    }
    return {
        start: node.source.start !== undefined
            ? {
                line: node.source.start.line,
                column: node.source.start.column - 1,
            }
            : undefined,
        end: node.source.end !== undefined
            ? {
                line: node.source.end.line,
                column: node.source.end.column,
            }
            : undefined,
    };
}
/**
 * Extracts a node range (like that of any ESLint node) from a parsed svelte style node.
 */
export function styleNodeRange(node) {
    if (node.source === undefined) {
        return [undefined, undefined];
    }
    return [
        node.source.start !== undefined ? node.source.start.offset : undefined,
        node.source.end !== undefined ? node.source.end.offset + 1 : undefined,
    ];
}
/**
 * Extracts a node location (like that of any ESLint node) from a parsed svelte selector node.
 */
export function styleSelectorNodeLoc(node) {
    return {
        start: node.source?.start !== undefined
            ? {
                line: node.source.start.line,
                column: node.source.start.column - 1,
            }
            : undefined,
        end: node.source?.end,
    };
}
/**
 * Fixes PostCSS AST locations to be relative to the whole file instead of relative to the <style> element.
 */
function fixPostCSSNodeLocation(node, styleElement) {
    if (node.source?.start?.offset !== undefined) {
        node.source.start.offset += styleElement.startTag.range[1];
    }
    if (node.source?.start?.line !== undefined) {
        node.source.start.line += styleElement.loc.start.line - 1;
    }
    if (node.source?.end?.offset !== undefined) {
        node.source.end.offset += styleElement.startTag.range[1];
    }
    if (node.source?.end?.line !== undefined) {
        node.source.end.line += styleElement.loc.start.line - 1;
    }
    if (node.source?.start?.line === styleElement.loc.start.line) {
        node.source.start.column += styleElement.startTag.loc.end.column;
    }
    if (node.source?.end?.line === styleElement.loc.start.line) {
        node.source.end.column += styleElement.startTag.loc.end.column;
    }
}
/**
 * Fixes selector AST locations to be relative to the whole file instead of relative to their parent rule.
 */
function fixSelectorNodeLocation(node, rule) {
    if (node.source === undefined) {
        return;
    }
    const ruleLoc = styleNodeLoc(rule);
    if (node.source.start !== undefined && ruleLoc.start !== undefined) {
        if (node.source.start.line === 1) {
            node.source.start.column += ruleLoc.start.column;
        }
        node.source.start.line += ruleLoc.start.line - 1;
    }
    else {
        node.source.start = undefined;
    }
    if (node.source.end !== undefined && ruleLoc.start !== undefined) {
        if (node.source.end.line === 1) {
            node.source.end.column += ruleLoc.start.column;
        }
        node.source.end.line += ruleLoc.start.line - 1;
    }
    else {
        node.source.end = undefined;
    }
}