eslint-rules/esbuild.ts

#!/usr/bin/env tsx
import assert from 'node:assert';
import { readFileSync } from 'node:fs';
import { resolve, extname, relative } from 'node:path';
import { isBuiltin } from 'node:module';
import esbuild from 'esbuild';
import type { Loader, Plugin } from 'esbuild';
import * as babel from '@babel/core';
import { memoize } from 'lodash';
import { gray, green } from 'picocolors';
import type { types as t, types } from '@babel/core';
import { dependencies } from './dist/package.json';
import { createMacro, type MacroHandler } from 'babel-plugin-macros';
import * as polyfill from './src/polyfill';

const polyfills = Object.keys(polyfill);

const ENV = process.env.NODE_ENV || 'development';
const PROD = ENV === 'production';

class HandlerMap {
  map = new Map<string, MacroHandler>();

  set(names: string | string[], handler: MacroHandler) {
    names = Array.isArray(names) ? names : [names];
    const macro = createMacro(handler);
    for (const name of names) {
      this.map.set(name, macro);
    }
    return this;
  }

  get keys() {
    return Array.from(this.map.keys());
  }

  resolvePath = (module: string) => module;
  require = (module: string) => this.map.get(module);
  isMacrosName = (module: string) => this.map.has(module);
}

const map = new HandlerMap()
  .set(
    'object.assign',
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('assign'))),
  )
  .set(
    ['object-values', 'object.values'],
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('values'))),
  )
  .set(
    'object.fromentries',
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('fromEntries'))),
  )
  .set(
    'object.entries',
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('entries'))),
  )
  .set(
    'hasown',
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('hasOwn'))),
  )
  .set(
    'has',
    replace(t => t.memberExpression(t.identifier('Object'), t.identifier('hasOwn'))),
  )
  .set(
    'array-includes',
    proto(t => t.identifier('includes')),
  )
  .set(
    'array.prototype.flatmap',
    proto(t => t.identifier('flatMap')),
  )
  .set(
    'array.prototype.flat',
    proto(t => t.identifier('flat')),
  )
  .set(
    'array.prototype.findlastindex',
    proto(t => t.identifier('findLastIndex')),
  )
  .set(
    'array.prototype.tosorted',
    proto(t => t.identifier('toSorted')),
  )
  .set(
    'string.prototype.matchall',
    proto(t => t.identifier('matchAll')),
  )
  .set(
    'object.groupby',
    replace(t =>
      t.memberExpression(
        t.callExpression(t.identifier('require'), [t.stringLiteral('lodash')]),
        t.identifier('groupBy'),
      ),
    ),
  );

// es-iterator-helpers/Iterator.prototype.*
const polyfillPath = resolve(__dirname, './src/polyfill.ts');
const requirePolyfill = (t: typeof types, name: string) =>
  t.memberExpression(
    t.callExpression(t.identifier('require'), [t.stringLiteral(polyfillPath)]),
    t.identifier(name),
  );
map.set(
  `es-iterator-helpers/Iterator.from`,
  replace(t => requirePolyfill(t, 'from')),
);
for (const name of polyfills) {
  map.set(
    `es-iterator-helpers/Iterator.prototype.${name}`,
    replace(t => requirePolyfill(t, name)),
  );
}

function replace(getReplacement: (types: typeof t) => t.Expression): MacroHandler {
  return ({ references, babel: { types: t } }) => {
    references.default.forEach(referencePath => {
      referencePath.replaceWith(getReplacement(t));
    });
  };
}

function proto(getProperty: (types: typeof t) => t.Expression): MacroHandler {
  return ({ references, babel: { types: t } }) => {
    references.default.forEach(referencePath => {
      const { parent, parentPath } = referencePath;
      assert(t.isCallExpression(parent));
      const [callee, ...rest] = parent.arguments;
      parentPath!.replaceWith(
        t.callExpression(
          t.memberExpression(callee as t.Expression, getProperty(t)),
          rest,
        ),
      );
    });
  };
}

export const babelPlugin: Plugin = {
  name: 'babel',
  setup(build) {
    const { keys, ...macroOptions } = map;

    build.onLoad({ filter: /\.[jt]sx?$/ }, args => {
      const { path } = args;
      if (path.includes('node_modules/')) {
        return null;
      }

      let source = readFileSync(path, 'utf-8')
        .replaceAll("require('object.hasown/polyfill')()", 'Object.hasOwn')
        .replaceAll("require('object.fromentries/polyfill')()", 'Object.fromEntries')
        .replaceAll(
          "Object.keys(require('prop-types'))",
          JSON.stringify(Object.keys(require('prop-types'))),
        );

      if (
        path.includes('packages/eslint-plugin-import/src/rules/') ||
        path.includes('packages/eslint-plugin-import/config/')
      ) {
        source = source.replace('\nmodule.exports = {', '\nexport default {');
      }

      const isFlow = source.includes('@flow');
      const loader = extname(path).slice(1) as Loader;

      if (!isFlow && !keys.some(key => source.includes(key))) {
        return { contents: source, loader };
      }

      const res = babel.transformSync(source, {
        filename: path,
        babelrc: false,
        configFile: false,
        parserOpts: {
          plugins: [isFlow ? 'flow' : 'typescript'],
        },
        plugins: [
          isFlow && '@babel/plugin-transform-flow-strip-types',
          ['babel-plugin-macros', macroOptions],
        ].filter(Boolean),
      })!;

      return {
        contents: res.code!,
        loader,
      };
    });
  },
};

declare global {
  interface Array<T> {
    filter(
      predicate: BooleanConstructor,
    ): Exclude<T, null | undefined | false | '' | 0>[];
  }
}

const log = memoize(console.log);

const plugins: Plugin[] = [
  babelPlugin,
  {
    name: 'alias',
    setup(build) {
      build.onResolve({ filter: /^jsx-ast-utils$/ }, () => ({
        path: resolve('./packages/jsx-ast-utils/src/index.js'),
      }));
      build.onResolve({ filter: /^jsx-ast-utils\/.+$/ }, ({ path }) => ({
        path:
          resolve('./packages/jsx-ast-utils/', path.slice('jsx-ast-utils/'.length)) +
          '.js',
      }));
    },
  },
];
if (process.env.DEBUG) {
  plugins.push({
    name: 'deps-check',
    setup(build) {
      const declared = new Set(Object.keys(dependencies));

      build.onResolve({ filter: /^.*$/ }, ({ path, importer }) => {
        if (
          !path.startsWith('./') &&
          !path.startsWith('../') &&
          !isBuiltin(path) &&
          path !== 'eslint' &&
          !path.startsWith('eslint/') &&
          !path.startsWith('eslint-module-utils/') &&
          !declared.has(path)
        ) {
          log(green(path), gray('from'), './' + relative(process.cwd(), importer));
        }
        return null;
      });
    },
  });
}

async function main(
  entry: string,
  outfile = entry
    .replace('./packages/', './dist/')
    .replace('src/', '')
    .replace('.ts', '.js'),
) {
  await esbuild.build({
    entryPoints: [entry],
    outfile,
    bundle: true,
    minify: PROD,
    platform: 'node',
    packages: 'external',
    sourcemap: 'linked',
    plugins,
    define: {},
    banner: {
      js: '/* eslint-disable */',
    },
  });
}

main('./packages/eslint-plugin-react/index.js');
main('./packages/eslint-plugin-import/src/index.js');
main('./packages/eslint-plugin-jsx-a11y/src/index.js');
main('./packages/eslint-plugin-react-hooks/index.ts');
main('./packages/eslint-plugin-n/lib/index.js');
main('./packages/eslint-import-resolver-typescript/src/index.ts');
main('./src/rules/index.ts', './dist/rules/index.js');
main('./src/index.ts', './dist/index.js');