Ambient Meta Support

lib/logger.js

@@ -147,16 +147,25 @@ function Logger(key, options) {
 Logger.prototype.log = function(statement, opts) {
     this._err = false;
     if (typeof statement === 'object') {
+        if (this.ambientMeta) {
+            statement.ambientMeta = this.ambientMeta;
+        }
         statement = JSON.parse(JSON.stringify(statement));
         statement = stringify(statement, null, 2, function() { return undefined; });
     }
+
+    if (typeof statement !== 'object' && this.ambientMeta) {
+        statement = `${JSON.stringify({message: statement, ambient_meta: this.ambientMeta})}`;
+    }
+
     var message = {
         timestamp: Date.now()
         , line: statement
         , level: this.source.level
         , app: this.source.app
         , env: this.source.env
     };
+
     if (opts) {
         if (typeof opts === 'string') {
             if (opts.length > configs.MAX_INPUT_LENGTH) {
@@ -227,6 +236,14 @@ Logger.prototype._bufferLog = function(message) {
     }
 };
 
+Logger.prototype.addProperty = function (meta) {
+    this.ambientMeta = meta;
+};
+
+Logger.prototype.removeProperty = function () {
+    this.ambientMeta = null;
+};
+
 Logger.prototype._flush = function(callback) {
     if (!callback || typeof callback !== 'function') {
         throw new Error('flush function expects a callback');
@@ -308,6 +325,7 @@ const flushAll = function(cb) {
             }
         });
     });
+
     if (errors.length > 0) {
         return cb(`The following errors happened while flushing all loggers: ${errors}`);
     }

test/logger.js

@@ -374,3 +374,44 @@ describe('Multiple loggers', function() {
         }, configs.FLUSH_INTERVAL + 200);
     });
 });
+
+describe('ambient meta', function() {
+    const ambientLogger = Logger.createLogger(testHelper.apikey, testHelper.options);
+
+    beforeEach(function() {
+        Logger.flushAll();
+    });
+
+    it('add string ambinet meta to a string log line', function() {
+        ambientLogger.addProperty('someAmbientMeta');
+        ambientLogger.log('Sent a string log');
+        ambientLogger.log('Sent a second string log');
+
+        assert(ambientLogger._buf[0].line === '{"message":"Sent a string log","ambient_meta":"someAmbientMeta"}');
+        assert(ambientLogger._buf[1].line === '{"message":"Sent a second string log","ambient_meta":"someAmbientMeta"}');
+    });
+    it('add an object ambinet meta to a string log line', function() {
+        ambientLogger.addProperty({someAmbientKey: 'value'});
+
+        ambientLogger.log('Sent a string log');
+        ambientLogger.log('Sent a second string log');
+
+        assert(ambientLogger._buf[0].line === '{"message":"Sent a string log","ambient_meta":{"someAmbientKey":"value"}}');
+        assert(ambientLogger._buf[1].line === '{"message":"Sent a second string log","ambient_meta":{"someAmbientKey":"value"}}');
+    });
+    it('add an object ambinet meta to an object log line', function() {
+        ambientLogger.addProperty({someAmbientKey: 'value'});
+
+        ambientLogger.log({k: 'v'});
+
+        assert(ambientLogger._buf[0].line === '{"message":"{\\n  \\"k\\": \\"v\\",\\n  \\"ambientMeta\\": {\\n    \\"someAmbientKey\\": \\"value\\"\\n  }\\n}","ambient_meta":{"someAmbientKey":"value"}}');
+    });
+    it('remove ambient meta', function() {
+        ambientLogger.addProperty('someAmbientMeta');
+        ambientLogger.log('Sent a string log');
+        ambientLogger.removeProperty();
+        ambientLogger.log('Sent a string log');
+        assert(ambientLogger._buf[0].line === '{"message":"Sent a string log","ambient_meta":"someAmbientMeta"}');
+        assert(ambientLogger._buf[1].line === 'Sent a string log');
+    });
+});