d3-view/src/bin/deps.js

import { readFile } from "fs";
import { handleError, info } from "./error";

//
//  Create an object which maps names with package information and stores it
//  in the ``condig.dependencies`` attribute.
//
//  The ``dependencies`` object is of the form
//  {
//      <dep-name>: {version: <dep-version>, main: <dep-main-file>}
//  }
export default function(deps, config, d3) {
  return new Promise(resolve => {
    deps = extendDeps([], deps, config, d3);
    readAll(deps, config, resolve);
  });
}

function readAll(deps, config, resolve) {
  if (!deps.length) return resolve(config);
  var dep = deps.splice(0, 1)[0],
    current = config.dependencies[dep.name];
  current = current || {};
  if (current.origin) return readAll(deps, config, resolve);

  readFile(
    `${config.node_modules}/${dep.name}/package.json`,
    "utf-8",
    (error, text) => {
      if (error) handleError(error, true);
      else {
        var json = JSON.parse(text),
          main = location(current.main || json.main);
        info(config, `${dep.name} @ ${dep.version}/${main}`);
        config.dependencies[dep.name] = {
          version: dep.version,
          main: main
        };
        if (dep.name.substring(0, 3) === "d3-")
          extendDeps(deps, json.dependencies, config, true);
      }
      readAll(deps, config, resolve);
    }
  );
}

function extendDeps(deps, dependencies, config, d3) {
  var version, t;
  dependencies = dependencies || {};
  Object.keys(dependencies).forEach(function(name) {
    if (
      !config.available.has(name) &&
      (!d3 || name.substring(0, 3) === "d3-")
    ) {
      version = dependencies[name];
      info(config, `${name} ${version}`);
      t = version.split(".").reduce((s, v) => s + +v, 0);
      if (t !== t)
        handleError("Cannot set dependency " + name + " " + version, true);
      else {
        deps.push({
          name: name,
          version: version
        });
        config.available.add(name);
      }
    }
  });
  return deps;
}

function location(main) {
  if (!main) return "";
  if (main.substring(0, 1) === "/") main = main.substring(1);
  else if (main.substring(0, 2) === "./") main = main.substring(2);
  return main;
}