initial commit

node_modules/v8flags/index.js

@@ -0,0 +1,162 @@
+// this entire module is depressing. i should have spent my time learning
+// how to patch v8 so that these options would just be available on the
+// process object.
+
+var os = require('os');
+var fs = require('fs');
+var path = require('path');
+var crypto = require('crypto');
+var execFile = require('child_process').execFile;
+var configPath = require('./config-path.js')(process.platform);
+var version = require('./package.json').version;
+var env = process.env;
+var user = env.LOGNAME || env.USER || env.LNAME || env.USERNAME || '';
+var exclusions = ['--help'];
+
+// This number must be incremented whenever the generated cache file changes.
+var CACHE_VERSION = 1;
+
+var configfile = '.v8flags-' + CACHE_VERSION + '-' + process.versions.v8 + '.' + crypto.createHash('md5').update(user).digest('hex') + '.json';
+
+var failureMessage = [
+  'Unable to cache a config file for v8flags to your home directory',
+  'or a temporary folder. To fix this problem, please correct your',
+  'environment by setting HOME=/path/to/home or TEMP=/path/to/temp.',
+  'NOTE: the user running this must be able to access provided path.',
+  'If all else fails, please open an issue here:',
+  'http://github.com/tkellen/js-v8flags',
+].join('\n');
+
+function fail(err) {
+  err.message += '\n\n' + failureMessage;
+  return err;
+}
+
+function openConfig(cb) {
+  fs.mkdir(configPath, function() {
+    tryOpenConfig(path.join(configPath, configfile), function(err, fd) {
+      if (err) {
+        return tryOpenConfig(path.join(os.tmpdir(), configfile), cb);
+      }
+      return cb(null, fd);
+    });
+  });
+}
+
+function tryOpenConfig(configpath, cb) {
+  try {
+    // if the config file is valid, it should be json and therefore
+    // node should be able to require it directly. if this doesn't
+    // throw, we're done!
+    var content = require(configpath);
+    process.nextTick(function() {
+      cb(null, content);
+    });
+  } catch (e) {
+    // if requiring the config file failed, maybe it doesn't exist, or
+    // perhaps it has become corrupted. instead of calling back with the
+    // content of the file, call back with a file descriptor that we can
+    // write the cached data to
+    fs.open(configpath, 'w+', function(err, fd) {
+      if (err) {
+        return cb(err);
+      }
+      return cb(null, fd);
+    });
+  }
+}
+
+// Node <= 9 outputs _ in flags with multiple words, while node 10
+// uses -. Both ways are accepted anyway, so always use `_` for better
+// compatibility.
+// We must not replace the first two --.
+function normalizeFlagName(flag) {
+  return '--' + flag.slice(4).replace(/-/g, '_');
+}
+
+// i can't wait for the day this whole module is obsolete because these
+// options are available on the process object. this executes node with
+// `--v8-options` and parses the result, returning an array of command
+// line flags.
+function getFlags(cb) {
+  execFile(process.execPath, ['--v8-options'], function(execErr, result) {
+    if (execErr) {
+      return cb(execErr);
+    }
+    // If the binary doesn't return flags in the way we expect, default to an empty array
+    // Reference https://github.com/gulpjs/v8flags/issues/53
+    var matchedFlags = result.match(/\s\s--[\w-]+/gm) || [];
+    var flags = matchedFlags
+      .map(normalizeFlagName)
+      .filter(function(name) {
+        return exclusions.indexOf(name) === -1;
+      });
+    return cb(null, flags);
+  });
+}
+
+// write some json to a file descriptor. if this fails, call back
+// with both the error and the data that was meant to be written.
+function writeConfig(fd, flags, cb) {
+  var json = JSON.stringify(flags);
+  var buf;
+  if (Buffer.from && Buffer.from !== Uint8Array.from) {
+    // Node.js 4.5.0 or newer
+    buf = Buffer.from(json);
+  } else {
+    // Old Node.js versions
+    // The typeof safeguard below is mostly against accidental copy-pasting
+    // and code rewrite, it never happens as json is always a string here.
+    if (typeof json === 'number') {
+      throw new Error('Unexpected type number');
+    }
+    buf = new Buffer(json);
+  }
+  return fs.write(fd, buf, 0, buf.length, 0 , function(writeErr) {
+    fs.close(fd, function(closeErr) {
+      var err = writeErr || closeErr;
+      if (err) {
+        return cb(fail(err), flags);
+      }
+      return cb(null, flags);
+    });
+  });
+}
+
+module.exports = function(cb) {
+  // bail early if this is not node
+  var isElectron = process.versions && process.versions.electron;
+  if (isElectron) {
+    return process.nextTick(function() {
+      cb(null, []);
+    });
+  }
+
+  // attempt to open/read cache file
+  openConfig(function(openErr, result) {
+    if (!openErr && typeof result !== 'number') {
+      return cb(null, result);
+    }
+    // if the result is not an array, we need to go fetch
+    // the flags by invoking node with `--v8-options`
+    getFlags(function(flagsErr, flags) {
+      // if there was an error fetching the flags, bail immediately
+      if (flagsErr) {
+        return cb(flagsErr);
+      }
+      // if there was a problem opening the config file for writing
+      // throw an error but include the flags anyway so that users
+      // can continue to execute (at the expense of having to fetch
+      // flags on every run until they fix the underyling problem).
+      if (openErr) {
+        return cb(fail(openErr), flags);
+      }
+      // write the config file to disk so subsequent runs can read
+      // flags out of a cache file.
+      return writeConfig(result, flags, cb);
+    });
+  });
+};
+
+module.exports.configfile = configfile;
+module.exports.configPath = configPath;