etherpad-lite/src/static/js/pluginfw/read-installed.js

// A copy of npm/lib/utils/read-installed.js
// that is hacked to not cache everything :)

// Walk through the file-system "database" of installed
// packages, and create a data object related to the
// installed versions of each package.

/*
This will traverse through all node_modules folders,
resolving the dependencies object to the object corresponding to
the package that meets that dep, or just the version/range if
unmet.

Assuming that you had this folder structure:

/path/to
+-- package.json { name = "root" }
`-- node_modules
    +-- foo {bar, baz, asdf}
    | +-- node_modules
    |   +-- bar { baz }
    |   `-- baz
    `-- asdf

where "foo" depends on bar, baz, and asdf, bar depends on baz,
and bar and baz are bundled with foo, whereas "asdf" is at
the higher level (sibling to foo), you'd get this object structure:

{ <package.json data>
, path: "/path/to"
, parent: null
, dependencies:
  { foo :
    { version: "1.2.3"
    , path: "/path/to/node_modules/foo"
    , parent: <Circular: root>
    , dependencies:
      { bar:
        { parent: <Circular: foo>
        , path: "/path/to/node_modules/foo/node_modules/bar"
        , version: "2.3.4"
        , dependencies: { baz: <Circular: foo.dependencies.baz> }
        }
      , baz: { ... }
      , asdf: <Circular: asdf>
      }
    }
  , asdf: { ... }
  }
}

Unmet deps are left as strings.
Extraneous deps are marked with extraneous:true
deps that don't meet a requirement are marked with invalid:true

to READ(packagefolder, parentobj, name, reqver)
obj = read package.json
installed = ./node_modules/*
if parentobj is null, and no package.json
  obj = {dependencies:{<installed>:"*"}}
deps = Object.keys(obj.dependencies)
obj.path = packagefolder
obj.parent = parentobj
if name, && obj.name !== name, obj.invalid = true
if reqver, && obj.version !satisfies reqver, obj.invalid = true
if !reqver && parentobj, obj.extraneous = true
for each folder in installed
  obj.dependencies[folder] = READ(packagefolder+node_modules+folder,
                                  obj, folder, obj.dependencies[folder])
# walk tree to find unmet deps
for each dep in obj.dependencies not in installed
  r = obj.parent
  while r
    if r.dependencies[dep]
      if r.dependencies[dep].verion !satisfies obj.dependencies[dep]
        WARN
        r.dependencies[dep].invalid = true
      obj.dependencies[dep] = r.dependencies[dep]
      r = null
    else r = r.parent
return obj


TODO:
1. Find unmet deps in parent directories, searching as node does up
as far as the left-most node_modules folder.
2. Ignore anything in node_modules that isn't a package folder.

*/


const npm = require('npm/lib/npm.js');
const fs = require('graceful-fs');
const path = require('path');
const asyncMap = require('slide').asyncMap;
const semver = require('semver');
const log = require('log4js').getLogger('pluginfw');

function readJson(file, callback) {
  fs.readFile(file, (er, buf) => {
    if (er) {
      callback(er);
      return;
    }
    try {
      callback(null, JSON.parse(buf.toString()));
    } catch (er) {
      callback(er);
    }
  });
}

module.exports = readInstalled;

function readInstalled(folder, cb) {
  /* This is where we clear the cache, these three lines are all the
   * new code there is */
  rpSeen = {};
  riSeen = [];
  const fuSeen = [];

  const d = npm.config.get('depth');
  readInstalled_(folder, null, null, null, 0, d, (er, obj) => {
    if (er) return cb(er);
    // now obj has all the installed things, where they're installed
    // figure out the inheritance links, now that the object is built.
    resolveInheritance(obj);
    cb(null, obj);
  });
}

var rpSeen = {};
function readInstalled_(folder, parent, name, reqver, depth, maxDepth, cb) {
  let installed,
    obj,
    real,
    link;

  fs.readdir(path.resolve(folder, 'node_modules'), (er, i) => {
    // error indicates that nothing is installed here
    if (er) i = [];
    installed = i.filter((f) => f.charAt(0) !== '.');
    next();
  });

  readJson(path.resolve(folder, 'package.json'), (er, data) => {
    obj = copy(data);

    if (!parent) {
      obj = obj || true;
      er = null;
    }
    return next(er);
  });

  fs.lstat(folder, (er, st) => {
    if (er) {
      if (!parent) real = true;
      return next(er);
    }
    fs.realpath(folder, (er, rp) => {
      real = rp;
      if (st.isSymbolicLink()) link = rp;
      next(er);
    });
  });

  let errState = null;
  let called = false;
  function next(er) {
    if (errState) return;
    if (er) {
      errState = er;
      return cb(null, []);
    }
    if (!installed || !obj || !real || called) return;
    called = true;
    if (rpSeen[real]) return cb(null, rpSeen[real]);
    if (obj === true) {
      obj = {dependencies: {}, path: folder};
      installed.forEach((i) => { obj.dependencies[i] = '*'; });
    }
    if (name && obj.name !== name) obj.invalid = true;
    obj.realName = name || obj.name;
    obj.dependencies = obj.dependencies || {};

    // "foo":"http://blah" is always presumed valid
    if (reqver &&
        semver.validRange(reqver) &&
        !semver.satisfies(obj.version, reqver)) {
      obj.invalid = true;
    }

    if (parent &&
        !(name in parent.dependencies) &&
        !(name in (parent.devDependencies || {}))) {
      obj.extraneous = true;
    }
    obj.path = obj.path || folder;
    obj.realPath = real;
    obj.link = link;
    if (parent && !obj.link) obj.parent = parent;
    rpSeen[real] = obj;
    obj.depth = depth;
    if (depth >= maxDepth) return cb(null, obj);
    asyncMap(installed, (pkg, cb) => {
      let rv = obj.dependencies[pkg];
      if (!rv && obj.devDependencies) rv = obj.devDependencies[pkg];
      readInstalled_(path.resolve(folder, `node_modules/${pkg}`)
          , obj, pkg, obj.dependencies[pkg], depth + 1, maxDepth
          , cb);
    }, (er, installedData) => {
      if (er) return cb(er);
      installedData.forEach((dep) => {
        obj.dependencies[dep.realName] = dep;
      });

      // any strings here are unmet things.  however, if it's
      // optional, then that's fine, so just delete it.
      if (obj.optionalDependencies) {
        Object.keys(obj.optionalDependencies).forEach((dep) => {
          if (typeof obj.dependencies[dep] === 'string') {
            delete obj.dependencies[dep];
          }
        });
      }
      return cb(null, obj);
    });
  }
}

// starting from a root object, call findUnmet on each layer of children
var riSeen = [];
function resolveInheritance(obj) {
  if (typeof obj !== 'object') return;
  if (riSeen.indexOf(obj) !== -1) return;
  riSeen.push(obj);
  if (typeof obj.dependencies !== 'object') {
    obj.dependencies = {};
  }
  Object.keys(obj.dependencies).forEach((dep) => {
    findUnmet(obj.dependencies[dep]);
  });
  Object.keys(obj.dependencies).forEach((dep) => {
    resolveInheritance(obj.dependencies[dep]);
  });
}

// find unmet deps by walking up the tree object.
// No I/O
const fuSeen = [];
function findUnmet(obj) {
  if (typeof obj !== 'object') return;
  if (fuSeen.indexOf(obj) !== -1) return;
  fuSeen.push(obj);
  const deps = obj.dependencies = obj.dependencies || {};
  Object.keys(deps)
      .filter((d) => typeof deps[d] === 'string')
      .forEach((d) => {
        let r = obj.parent;
        let found = null;
        while (r && !found && typeof deps[d] === 'string') {
        // if r is a valid choice, then use that.
          found = r.dependencies[d];
          if (!found && r.realName === d) found = r;

          if (!found) {
            r = r.link ? null : r.parent;
            continue;
          }
          if (typeof deps[d] === 'string' &&
            !semver.satisfies(found.version, deps[d])) {
          // the bad thing will happen
            log.warn(`${obj.path} requires ${d}@'${deps[d]
            }' but will load\n${
              found.path},\nwhich is version ${found.version}`
            , 'unmet dependency');
            found.invalid = true;
          }
          deps[d] = found;
        }
      });
  return obj;
}

function copy(obj) {
  if (!obj || typeof obj !== 'object') return obj;
  if (Array.isArray(obj)) return obj.map(copy);

  const o = {};
  for (const i in obj) o[i] = copy(obj[i]);
  return o;
}

if (module === require.main) {
  const util = require('util');
  console.error('testing');

  let called = 0;
  npm.load({}, (err) => {
    if (err != null) throw err;
    readInstalled(process.cwd(), (er, map) => {
      console.error(called++);
      if (er) return console.error(er.stack || er.message);
      cleanup(map);
      console.error(util.inspect(map, true, 10, true));
    });
  });

  const seen = [];
  function cleanup(map) {
    if (seen.indexOf(map) !== -1) return;
    seen.push(map);
    for (var i in map) {
      switch (i) {
        case '_id':
        case 'path':
        case 'extraneous': case 'invalid':
        case 'dependencies': case 'name':
          continue;
        default: delete map[i];
      }
    }
    const dep = map.dependencies;
    if (dep) {
      for (var i in dep) {
        if (typeof dep[i] === 'object') {
          cleanup(dep[i]);
        }
      }
    }
    return map;
  }
}