migrated logLevelFilter tests to mocha, changed filter api slightly

lib/appenders/logLevelFilter.js

@@ -1,21 +1,40 @@
 "use strict";
 var levels = require('../levels')
+, debug = require('debug')('log4js:logLevelFilter')
 , log4js = require('../log4js');
 
-function logLevelFilter (levelString, appender) {
-  var level = levels.toLevel(levelString);
+function logLevelFilter(allowedLevels, appender) {
   return function(logEvent) {
-    if (logEvent.level.isGreaterThanOrEqualTo(level)) {
+    debug("Checking ", logEvent.level, " against ", allowedLevels);
+    if (allowedLevels.some(function(item) { return item.level === logEvent.level.level; })) {
+      debug("Sending ", logEvent, " to appender ", appender);
       appender(logEvent);
     }
   };
 }
 
-function configure(config) {
-  log4js.loadAppender(config.appender.type);
-  var appender = log4js.appenderMakers[config.appender.type](config.appender);
-  return logLevelFilter(config.level, appender);
+function configure(config, appenderByName) {
+  if (!Array.isArray(config.allow)) {
+    throw new Error("No allowed log levels specified.");
+  }
+
+  var allowedLevels = config.allow.map(function(allowed) {
+    var level = levels.toLevel(allowed);
+    if (!level) {
+      throw new Error("Unrecognised log level '" + allowed + "'.");
+    }
+    return level;
+  });
+
+  if (allowedLevels.length === 0) {
+    throw new Error("No allowed log levels specified.");
+  }
+
+  if (!config.appender) {
+    throw new Error("Missing an appender.");
+  }
+
+  return logLevelFilter(allowedLevels, appenderByName(config.appender));
 }
 
-exports.appender = logLevelFilter;
 exports.configure = configure;

lib/log4js.js

@@ -200,6 +200,14 @@ function clearAppenders () {
   appenders = {};
 }
 
+function appenderByName(name) {
+  if (appenders.hasOwnProperty(name)) {
+    return appenders[name];
+  } else {
+    throw new Error("Appender '" + name + "' not found.");
+  }
+}
+
 function configureAppenders(appenderMap) {
   clearAppenders();
   Object.keys(appenderMap).forEach(function(appenderName) {
@@ -207,7 +215,7 @@ function configureAppenders(appenderMap) {
       loadAppender(appenderConfig.type);
       appenderConfig.makers = appenderMakers;
       try {
-        appenders[appenderName] = appenderMakers[appenderConfig.type](appenderConfig);
+        appenders[appenderName] = appenderMakers[appenderConfig.type](appenderConfig, appenderByName);
       } catch(e) {
         throw new Error("log4js configuration problem for appender '" + appenderName + "'. Error was " + e.stack);
       }