generator-react-native-vector-icons/generators/app/generateGlyphmap.js

Generates React Native vector icons font library

import fs from 'node:fs';
import postcss from 'postcss';
import parser from 'postcss-selector-parser';
const extractGlyphMapFromCodepoints = (fileName) => {
    const codepoints = fs.readFileSync(fileName, { encoding: 'utf8' }).split('\n');
    const glyphMap = {};
    codepoints.forEach((point) => {
        const parts = point.split(' ');
        if (parts[0] && parts[1]) {
            glyphMap[parts[0].replace(/_/g, '-')] = Number.parseInt(parts[1], 16);
        }
    });
    return glyphMap;
};
const extractGlyphMapFromCss = (fileName, selectorPrefix) => {
    const css = fs.readFileSync(fileName, 'utf-8');
    const glyphMap = {};
    const selectorPattern = `${escapeRegExp(selectorPrefix)}([A-Za-z0-9_-]+)::?before`;
    postcss.parse(css).walkRules((rule) => {
        const iconNames = [];
        const transform = (selectors) => {
            selectors.walk((selector) => {
                const md = selector.toString().match(selectorPattern);
                if (md?.[1]) {
                    iconNames.push(md[1]);
                }
            });
        };
        parser(transform).processSync(rule.selector);
        const contents = [];
        rule.walkDecls('content', (decl) => {
            const content = decl.value.replace(/['"]/g, ''); // Remove quotes
            contents.push(content);
        });
        const content = contents[0];
        if (!content || content === 'var(--fa)') {
            return;
        }
        const codePoint = Number.parseInt(content.slice(1), 16);
        iconNames.forEach((iconName) => {
            glyphMap[iconName] = codePoint;
        });
    });
    // TODO: Quick hack for fontawesome - refactor this to be more general
    const selectorPatternFA = `${escapeRegExp(selectorPrefix)}([A-Za-z0-9_-]+)$`;
    postcss.parse(css).walkRules((rule) => {
        const iconNames = [];
        const transform = (selectors) => {
            selectors.walk((selector) => {
                const md = selector.toString().match(selectorPatternFA);
                if (md?.[1]) {
                    iconNames.push(md[1]);
                }
            });
        };
        parser(transform).processSync(rule.selector);
        const contents = [];
        rule.walkDecls('--fa', (decl) => {
            const content = decl.value.replace(/['"]/g, ''); // Remove quotes
            contents.push(content);
        });
        const content = contents[0];
        if (!content) {
            return;
        }
        const codePoint = Number.parseInt(content.slice(1), 16);
        iconNames.forEach((iconName) => {
            glyphMap[iconName] = codePoint;
        });
    });
    return glyphMap;
};
const escapeRegExp = (str) => str.replace(/[-[\]/{}()*+?.\\^$|]/g, '\\$&');
export const generateGlyphmap = (mode, fileName, selectorPrefix = '.icon-') => {
    if (!fileName) {
        throw new Error('No files provided');
    }
    const glyphMap = mode === 'css' ? extractGlyphMapFromCss(fileName, selectorPrefix) : extractGlyphMapFromCodepoints(fileName);
    return JSON.stringify(glyphMap, null, '  ');
};