added exceptionToMeta method for filtering returned meta object

Readme.md

@@ -117,6 +117,8 @@ The logger needs to be added AFTER the express router(`app.router)`) and BEFORE
     requestWhitelist: [String] // Array of request properties to log. Overrides global requestWhitelist for this instance
     level: String or function(req, res, err) { return String; }// custom log level for errors (default is 'error'). Assign a function to dynamically set the log level based on request, response, and the exact error.
     dynamicMeta: function(req, res, err) { return [Object]; } // Extract additional meta data from request or response (typically req.user data if using passport). meta must be true for this function to be activated
+    exceptionToMeta: function(error){return Object; } // Function to format the returned meta information on error log. If not given `winston.exception.getAllInfo` will be used by default
+    blacklistedMetaFields: [String] // fields to blacklist from meta data
 ```
 
 To use winston's existing transports, set `transports` to the values (as in key-value) of the `winston.default.transports` object. This may be done, for example, by using underscorejs: `transports: _.values(winston.default.transports)`.

index.js

@@ -123,6 +123,8 @@ exports.errorLogger = function errorLogger(options) {
     options.metaField = options.metaField || null;
     options.level = options.level || 'error';
     options.dynamicMeta = options.dynamicMeta || function(req, res, err) { return null; };
+    options.exceptionToMeta = options.exceptionToMeta || winston.exception.getAllInfo;
+    options.blacklistedMetaFields = options.blacklistedMetaFields || [];
 
     // Using mustache style templating
     var getTemplate = function(msg, data) {
@@ -131,8 +133,8 @@ exports.errorLogger = function errorLogger(options) {
 
     return function (err, req, res, next) {
 
-        // Let winston gather all the error data.
-        var exceptionMeta = winston.exception.getAllInfo(err);
+      // Let winston gather all the error data
+        var exceptionMeta = _.omit(options.exceptionToMeta(err), options.blacklistedMetaFields);
         exceptionMeta.req = filterObject(req, options.requestWhitelist, options.requestFilter);
 
         if(options.dynamicMeta) {

test/test.js

@@ -229,6 +229,47 @@ describe('express-winston', function () {
       });
     });
 
+    describe('exceptionToMeta option', function () {
+      it('should, use exceptionToMeta function when given', function () {
+        function exceptionToMeta(error) {
+          return {
+            stack: error.stack && error.stack.split('\n')
+          };
+        }
+
+        var testHelperOptions = { loggerOptions: { exceptionToMeta: exceptionToMeta } };
+        return errorLoggerTestHelper(testHelperOptions).then(function (result) {
+          result.log.meta.stack.should.be.ok();
+          result.log.meta.should.not.have.property('trace');
+        });
+      });
+
+      it('should, use getAllInfo function when not given', function () {
+        var testHelperOptions = { loggerOptions: { } };
+        return errorLoggerTestHelper(testHelperOptions).then(function (result) {
+          result.log.meta.should.have.property('date');
+          result.log.meta.should.have.property('process');
+          result.log.meta.should.have.property('os');
+          result.log.meta.should.have.property('trace');
+          result.log.meta.should.have.property('stack');
+        });
+      });
+    });
+
+    describe('blacklistedMetaFields option', function () {
+      it('should, remove given fields from the meta result', function () {
+        var testHelperOptionsWithBlacklist = { loggerOptions: { blacklistedMetaFields: ['trace'] } };
+        return errorLoggerTestHelper(testHelperOptionsWithBlacklist).then(function (result) {
+          result.log.meta.should.not.have.property('trace');
+        });
+
+        var testHelperOptionsWithoutBlacklist = { loggerOptions: {} };
+        return errorLoggerTestHelper(testHelperOptionsWithoutBlacklist).then(function (result) {
+          result.log.meta.should.have.property('trace');
+        });
+      });
+    });
+
     describe('metaField option', function () {
       it('should, when using a custom metaField, log the custom metaField', function () {
         var testHelperOptions = {loggerOptions: {metaField: 'metaField'}};