log4js-node/test/configureNoLevels-test.js

"use strict";
// This test shows unexpected behaviour for log4js.configure() in log4js-node@0.4.3 and earlier:
// 1) log4js.configure(), log4js.configure(null),
// log4js.configure({}), log4js.configure(<some object with no levels prop>)
// all set all loggers levels to trace, even if they were previously set to something else.
// 2) log4js.configure({levels:{}}), log4js.configure({levels: {foo:
// bar}}) leaves previously set logger levels intact.
//

// Basic set up
var vows = require('vows');
var assert = require('assert');
var toLevel = require('../lib/levels').toLevel;

// uncomment one or other of the following to see progress (or not) while running the tests
// var showProgress = console.log;
var showProgress = function() {};


// Define the array of levels as string to iterate over.
var strLevels= ['Trace','Debug','Info','Warn','Error','Fatal'];

// setup the configurations we want to test
var configs = {
  'nop': 'nop', // special case where the iterating vows generator will not call log4js.configure
  'is undefined': undefined,
  'is null': null,
  'is empty': {},
  'has no levels': {foo: 'bar'},
  'has null levels': {levels: null},
  'has empty levels': {levels: {}},
  'has random levels': {levels: {foo: 'bar'}},
  'has some valid levels': {levels: {A: 'INFO'}}
};

// Set up the basic vows batches for this test
var batches = [];


function getLoggerName(level) {
  return level+'-logger';
}

// the common vows top-level context, whether log4js.configure is called or not
// just making sure that the code is common,
// so that there are no spurious errors in the tests themselves.
function getTopLevelContext(nop, configToTest, name) {
  return {
    topic: function() {
      var log4js = require('../lib/log4js');
      // create loggers for each level,
      // keeping the level in the logger's name for traceability
      strLevels.forEach(function(l) {
        log4js.getLogger(getLoggerName(l)).setLevel(l);
      });

      if (!nop) {
        showProgress('** Configuring log4js with', configToTest);
        log4js.configure(configToTest);
      }
      else {
        showProgress('** Not configuring log4js');
      }
      return log4js;
    }
  };
}

showProgress('Populating batch object...');

function checkForMismatch(topic) {
  var er = topic.log4js.levels.toLevel(topic.baseLevel)
    .isLessThanOrEqualTo(topic.log4js.levels.toLevel(topic.comparisonLevel));

  assert.equal(
    er, 
    topic.expectedResult, 
    'Mismatch: for setLevel(' + topic.baseLevel + 
      ') was expecting a comparison with ' + topic.comparisonLevel + 
      ' to be ' + topic.expectedResult
  );
}

function checkExpectedResult(topic) {
  var result = topic.log4js
    .getLogger(getLoggerName(topic.baseLevel))
    .isLevelEnabled(topic.log4js.levels.toLevel(topic.comparisonLevel));
  
  assert.equal(
    result, 
    topic.expectedResult, 
    'Failed: ' + getLoggerName(topic.baseLevel) + 
      '.isLevelEnabled( ' + topic.comparisonLevel + ' ) returned ' + result
  );
}

function setupBaseLevelAndCompareToOtherLevels(baseLevel) {
  var baseLevelSubContext = 'and checking the logger whose level was set to '+baseLevel ;
  var subContext = { topic: baseLevel };
  batch[context][baseLevelSubContext] = subContext;

  // each logging level has strLevels sub-contexts,
  // to exhaustively test all the combinations of 
  // setLevel(baseLevel) and isLevelEnabled(comparisonLevel) per config
  strLevels.forEach(compareToOtherLevels(subContext));
}

function compareToOtherLevels(subContext) {
  var baseLevel = subContext.topic;

  return function (comparisonLevel) {
    var comparisonLevelSubContext = 'with isLevelEnabled('+comparisonLevel+')';

    // calculate this independently of log4js, but we'll add a vow 
    // later on to check that we're not mismatched with log4js
    var expectedResult = strLevels.indexOf(baseLevel) <= strLevels.indexOf(comparisonLevel);

    // the topic simply gathers all the parameters for the vow 
    // into an object, to simplify the vow's work.
    subContext[comparisonLevelSubContext] = {
      topic: function(baseLevel, log4js) {
        return {
          comparisonLevel: comparisonLevel, 
          baseLevel: baseLevel, 
          log4js: log4js, 
          expectedResult: expectedResult
        };
      }
    };

    var vow = 'should return '+expectedResult;
    subContext[comparisonLevelSubContext][vow] = checkExpectedResult;
    
    // the extra vow to check the comparison between baseLevel and
    // comparisonLevel we performed earlier matches log4js'
    // comparison too
    var subSubContext = subContext[comparisonLevelSubContext];
    subSubContext['finally checking for comparison mismatch with log4js'] = checkForMismatch;
  };
}

// Populating the batches programmatically, as there are 
// (configs.length x strLevels.length x strLevels.length) = 324 
// possible test combinations
for (var cfg in configs) {
  var configToTest = configs[cfg];
  var nop = configToTest === 'nop';
  var context;
  if (nop) {
    context = 'Setting up loggers with initial levels, then NOT setting a configuration,';
  }
  else {
    context = 'Setting up loggers with initial levels, then setting a configuration which '+cfg+',';
  }

  showProgress('Setting up the vows batch and context for '+context);
  // each config to be tested has its own vows batch with a single top-level context
  var batch={};
  batch[context]= getTopLevelContext(nop, configToTest, context);
  batches.push(batch);

  // each top-level context has strLevels sub-contexts, one per logger 
  // which has set to a specific level in the top-level context's topic
  strLevels.forEach(setupBaseLevelAndCompareToOtherLevels);
}

showProgress('Running tests');
var v = vows.describe('log4js.configure(), with or without a "levels" property');

batches.forEach(function(batch) {v=v.addBatch(batch);});

v.export(module);