azure-cli/lib/util/patch-winston.js

Microsoft Azure Cross Platform Command Line tool

//
// Copyright (c) Microsoft and contributors.  All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//
// See the License for the specific language governing permissions and
// limitations under the License.
//

var fs = require('fs');
var tty = require('tty');
var winston = require('winston');
var config = require('winston/lib/winston/config');
var common = require('winston/lib/winston/common');

/*
    This patch overrides the winston 'Console.log' and 'common.log' methods
    in order to introduce the 'options.terse' flag.

    See "patch:" comments for alterations.
*/

var isatty1 = tty.isatty(1);
var isatty2 = tty.isatty(2);

winston.transports.Console.prototype.log = function (level, msg, meta, callback) {
  if (this.silent) {
    return callback(null, true);
  }

  var isStdErr = level === 'error' || level === 'debug';
  var isatty = isStdErr ? isatty2 : isatty1;

  var self = this, output = common.log({
    colorize:  isatty ? this.colorize : false, /* patch: do not colorize file and pipe output */
    json:      this.json,
    terse:     this.terse, /* patch: terse flag added as an option */
    level:     level,
    message:   msg,
    meta:      meta,
    stringify: this.stringify,
    timestamp: this.timestamp
  });

  if (isatty) { /* patch: use util only for tty output */
    if (isStdErr) {
      console.error(output);
    }
    else {
      console.log(output);
    }

    //
    // Emit the `logged` event immediately because the event loop
    // will not exit until `process.stdout` has drained anyway.
    //
    self.emit('logged');
  } else { /* patch: remove all colorization for file or pipe output */
    // remove any colorization
    var out = output.replace(/\x1b\[[0-9]+m/g, '') + '\n';
    fs.writeSync(isStdErr ? 2 : 1, out);
  }
  callback(null, true);
};

common.log = function (options) {
  var timestampFn = typeof options.timestamp === 'function' ? options.timestamp : common.timestamp,
      timestamp   = options.timestamp ? timestampFn() : null,
      meta        = options.meta, /* patch: don't do common.clone */
      output;

  /* patch: only format data as json */
  if (options.json && options.level === 'data') {
    output         = meta || {};
    /* patch: don't include level and message into the json output */
    /*
    output.level   = options.level;
    output.message = options.message;
    */

    if (timestamp) {
      output.timestamp = timestamp;
    }

    /* patch: JSON.stringify to output indented json */
    return typeof options.stringify === 'function' ? options.stringify(output) : JSON.stringify(output, null, 2);
  }

  output = timestamp ? timestamp + ' - ' : '';

  /* patch: terse flag will not add 'level: ' to output lines */
  if (options.terse) {
    output += options.message;
  } else {
    output += options.colorize ? config.colorize(options.level) : options.level;
    output += (': ' + options.message);
  }

  if (meta) {
    if (typeof meta !== 'object') {
      output += ' ' + meta;
    } else if (Object.keys(meta).length > 0) {
      output += ' ' + common.serialize(meta);
    }
  }

  return output;
};