rollup-pre-alias.config.js

"use strict";

import fs from "fs";
import path from "path";

import commonjs from '@rollup/plugin-commonjs';
import resolveNode from "@rollup/plugin-node-resolve";
import replace from "@rollup/plugin-replace";

// We only need this for its version (we inject it into a require)
import elliptic from "elliptic";

function getSigningKeyConfig() {

    const plugins = [ ];

    // Remove the buffer check from BN.js
    plugins.push(replace({
        "require('buffer')": "/*RicMoo:ethers*/(null)",
        include: "**/lib/bn.js",
        delimiters: [ '', '' ]
    }));

    // Replace the package.json in elliptic
    plugins.push(replace({
        "require('../package.json')": `/*RicMoo:ethers*/{ version: "${ elliptic.version }" }`,
        include: "**/lib/elliptic.js",
        delimiters: [ '', '' ]
    }));

    // Nuke a bunch of requires we don't need in elliptic
    const thrower = "(function() { throw new Error('unsupported'); })";
    const crash = "(null).crash()";
    [
        { name: "./edwards", filename: "curve/index.js" },
        { name: "./mont", filename: "curve/index.js" },
        { name: "./elliptic/eddsa", filename: "lib/elliptic.js" },
        { name: "brorand", filename: "ec/index.js", text: thrower },
        { name: "brorand", filename: "lib/elliptic.js", text: thrower },
        { name: "./precomputed/secp256k1", filename: "elliptic/curves.js", text: crash },
    ].forEach(({ name, filename, text }) => {
        if (text == null) { text = "(null)"; }
        const replacement = {
            include: `**/${ filename }`,
            delimiters: [ '', '' ]
        };
        replacement[`require('${ name }')`] = `/*RicMoo:ethers:require(${ name })*/${ text }`,
        plugins.push(replace(replacement));
    });

    // Keep @ethersproject imports, merge anything else
    plugins.push(resolveNode({
        //resolveOnly: ((name === "ethers") ? []: [ /^(?!(@ethersproject|ethers))/ ]),
        resolveOnly: [ /^(?!(@ethersproject|ethers|bn\.js|hash\.js))/ ],
        mainFields: [ "module", "browser", "main" ],
        preferBuiltins: false
    }));

    // Our CommonJS dependencies that are not rollup-friendly
    plugins.push(commonjs({ }));

    // Write out a dummy TypeScript definition
    const typeDef = "//This file generated by rollup-pre-alias.config.js; do NOT modify\ndeclare const EC: any;\nexport { EC };"
    fs.writeFileSync(path.resolve(__dirname, "packages/signing-key/lib._esm/browser-elliptic.d.ts"), typeDef);

    return {
        input: `packages/signing-key/lib._esm/elliptic.js`,
        output: {
            file: `packages/signing-key/lib._esm/browser-elliptic.js`,
            format: "esm",
            sourcemap: true,
            exports: "named"
        },
        context: "window",
        treeshake: false,
        plugins
    };
}

const configs = [
    getSigningKeyConfig()
];

export default configs;