improv(logger): switch key order for better readability

docs/core/logger.md

@@ -148,15 +148,15 @@ In each case, the printed log will look like this:
 
     ```json hl_lines="2-6"
     {
+        "level": "INFO",
+        "message": "This is an INFO log with some context",
+        "timestamp": "2021-12-12T21:21:08.921Z",
+        "service": "serverlessAirline",
         "cold_start": true,
         "function_arn": "arn:aws:lambda:eu-west-1:123456789012:function:shopping-cart-api-lambda-prod-eu-west-1",
         "function_memory_size": 128,
         "function_request_id": "c6af9ac6-7b61-11e6-9a41-93e812345678",
         "function_name": "shopping-cart-api-lambda-prod-eu-west-1",
-        "level": "INFO",
-        "message": "This is an INFO log with some context",
-        "service": "serverlessAirline",
-        "timestamp": "2021-12-12T21:21:08.921Z",
         "xray_trace_id": "abcdef123456abcdef123456abcdef123456"
     }
     ```

examples/snippets/logger/customTimezoneOutput.json

@@ -2,17 +2,17 @@
   {
     "level": "INFO",
     "message": "Hello, World!",
-    "sampling_rate": 0,
-    "service": "serverlessAirline",
     "timestamp": "2024-07-01T11:00:37.886Z",
+    "service": "serverlessAirline",
+    "sampling_rate": 0,
     "xray_trace_id": "1-66828c55-2bb635c65eb609c820ebe7bc"
   },
   {
     "level": "INFO",
     "message": "Ciao, Mondo!",
-    "sampling_rate": 0,
-    "service": "serverlessAirline",
     "timestamp": "2024-07-01T13:00:37.934+02:00",
+    "service": "serverlessAirline",
+    "sampling_rate": 0,
     "xray_trace_id": "1-66828c55-2bb635c65eb609c820ebe7bc"
   }
 ]

examples/snippets/logger/reorderLogKeysOutput.json

@@ -1,9 +1,9 @@
 {
-  "timestamp": "2024-09-03T02:59:06.603Z",
-  "additionalKey": "additionalValue",
   "level": "INFO",
   "message": "Hello, World!",
-  "sampling_rate": 0,
+  "timestamp": "2024-09-03T02:59:06.603Z",
   "service": "serverlessAirline",
+  "additionalKey": "additionalValue",
+  "sampling_rate": 0,
   "xray_trace_id": "1-66d67b7a-79bc7b2346b32af01b437cf8"
-}
+}

examples/snippets/logger/unserializableValues.json

@@ -1,9 +1,13 @@
 {
   "level": "INFO",
   "message": "Serialize with custom serializer",
-  "sampling_rate": 0,
-  "service": "serverlessAirline",
   "timestamp": "2024-07-07T09:52:14.212Z",
+  "service": "serverlessAirline",
+  "sampling_rate": 0,
   "xray_trace_id": "1-668a654d-396c646b760ee7d067f32f18",
-  "serializedValue": [1, 2, 3]
+  "serializedValue": [
+    1,
+    2,
+    3
+  ]
 }

packages/logger/src/formatter/PowertoolsLogFormatter.ts

@@ -44,16 +44,16 @@ class PowertoolsLogFormatter extends LogFormatter {
     const baseAttributes: Partial<PowertoolsStandardKeys> &
       Partial<PowertoolsLambdaContextKeys> &
       LogAttributes = {
+      level: attributes.logLevel,
+      message: attributes.message,
+      timestamp: this.formatTimestamp(attributes.timestamp),
+      service: attributes.serviceName,
       cold_start: attributes.lambdaContext?.coldStart,
       function_arn: attributes.lambdaContext?.invokedFunctionArn,
       function_memory_size: attributes.lambdaContext?.memoryLimitInMB,
       function_name: attributes.lambdaContext?.functionName,
       function_request_id: attributes.lambdaContext?.awsRequestId,
-      level: attributes.logLevel,
-      message: attributes.message,
       sampling_rate: attributes.sampleRateValue,
-      service: attributes.serviceName,
-      timestamp: this.formatTimestamp(attributes.timestamp),
       xray_trace_id: attributes.xRayTraceId,
     };
 

packages/logger/tests/unit/formatters.test.ts

@@ -185,7 +185,7 @@ describe('Formatters', () => {
   it('when `logRecordOrder` is set, it orders the attributes in the log item', () => {
     // Prepare
     const formatter = new PowertoolsLogFormatter({
-      logRecordOrder: ['message', 'timestamp', 'serviceName', 'environment'],
+      logRecordOrder: ['message', 'timestamp', 'service'],
     });
     const additionalLogAttributes: LogAttributes = {};
 
@@ -198,21 +198,19 @@ describe('Formatters', () => {
     const response = value.getAttributes();
 
     // Assess
-    expect(JSON.stringify(response)).toEqual(
-      JSON.stringify({
-        message: 'This is a WARN log',
-        timestamp: '2016-06-20T12:08:10.000Z',
-        cold_start: true,
-        function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
-        function_memory_size: '123',
-        function_name: 'my-lambda-function',
-        function_request_id: 'abcdefg123456789',
-        level: 'WARN',
-        sampling_rate: 0.25,
-        service: 'hello-world',
-        xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
-      })
-    );
+    expect(response).toStrictEqual({
+      message: 'This is a WARN log',
+      timestamp: '2016-06-20T12:08:10.000Z',
+      service: 'hello-world',
+      level: 'WARN',
+      cold_start: true,
+      function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
+      function_memory_size: '123',
+      function_name: 'my-lambda-function',
+      function_request_id: 'abcdefg123456789',
+      sampling_rate: 0.25,
+      xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
+    });
   });
 
   it('when `logRecordOrder` is set, it orders the attributes in the log item taking `additionalLogAttributes` into consideration', () => {
@@ -222,8 +220,8 @@ describe('Formatters', () => {
         'message',
         'additional_key',
         'timestamp',
-        'serviceName',
-        'environment',
+        'level',
+        'service',
       ]),
     });
     const additionalLogAttributes: LogAttributes = {
@@ -240,23 +238,21 @@ describe('Formatters', () => {
     const response = value.getAttributes();
 
     // Assess
-    expect(JSON.stringify(response)).toEqual(
-      JSON.stringify({
-        message: 'This is a WARN log',
-        additional_key: 'additional_value',
-        timestamp: '2016-06-20T12:08:10.000Z',
-        cold_start: true,
-        function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
-        function_memory_size: '123',
-        function_name: 'my-lambda-function',
-        function_request_id: 'abcdefg123456789',
-        level: 'WARN',
-        sampling_rate: 0.25,
-        service: 'hello-world',
-        xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
-        another_key: 'another_value',
-      })
-    );
+    expect(response).toStrictEqual({
+      message: 'This is a WARN log',
+      additional_key: 'additional_value',
+      timestamp: '2016-06-20T12:08:10.000Z',
+      level: 'WARN',
+      service: 'hello-world',
+      cold_start: true,
+      function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
+      function_memory_size: '123',
+      function_name: 'my-lambda-function',
+      function_request_id: 'abcdefg123456789',
+      sampling_rate: 0.25,
+      xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
+      another_key: 'another_value',
+    });
   });
 
   it('when `logRecordOrder` is set, even if a key does not exist in attributes, it orders the attributes correctly', () => {
@@ -267,8 +263,7 @@ describe('Formatters', () => {
         'additional_key',
         'not_present',
         'timestamp',
-        'serviceName',
-        'environment',
+        'level',
       ],
     });
     const additionalLogAttributes: LogAttributes = {
@@ -284,22 +279,20 @@ describe('Formatters', () => {
     const response = value.getAttributes();
 
     // Assess
-    expect(JSON.stringify(response)).toEqual(
-      JSON.stringify({
-        message: 'This is a WARN log',
-        additional_key: 'additional_value',
-        timestamp: '2016-06-20T12:08:10.000Z',
-        cold_start: true,
-        function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
-        function_memory_size: '123',
-        function_name: 'my-lambda-function',
-        function_request_id: 'abcdefg123456789',
-        level: 'WARN',
-        sampling_rate: 0.25,
-        service: 'hello-world',
-        xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
-      })
-    );
+    expect(response).toStrictEqual({
+      message: 'This is a WARN log',
+      additional_key: 'additional_value',
+      timestamp: '2016-06-20T12:08:10.000Z',
+      level: 'WARN',
+      service: 'hello-world',
+      cold_start: true,
+      function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
+      function_memory_size: '123',
+      function_name: 'my-lambda-function',
+      function_request_id: 'abcdefg123456789',
+      sampling_rate: 0.25,
+      xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
+    });
   });
 
   it('when logRecordOrder is not set, it will not order the attributes in the log item', () => {
@@ -318,22 +311,20 @@ describe('Formatters', () => {
     const response = value.getAttributes();
 
     // Assess
-    expect(JSON.stringify(response)).toEqual(
-      JSON.stringify({
-        cold_start: true,
-        function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
-        function_memory_size: '123',
-        function_name: 'my-lambda-function',
-        function_request_id: 'abcdefg123456789',
-        level: 'WARN',
-        message: 'This is a WARN log',
-        sampling_rate: 0.25,
-        service: 'hello-world',
-        timestamp: '2016-06-20T12:08:10.000Z',
-        xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
-        additional_key: 'additional_value',
-      })
-    );
+    expect(response).toStrictEqual({
+      level: 'WARN',
+      message: 'This is a WARN log',
+      timestamp: '2016-06-20T12:08:10.000Z',
+      service: 'hello-world',
+      cold_start: true,
+      function_arn: 'arn:aws:lambda:eu-west-1:123456789012:function:Example',
+      function_memory_size: '123',
+      function_name: 'my-lambda-function',
+      function_request_id: 'abcdefg123456789',
+      sampling_rate: 0.25,
+      xray_trace_id: '1-5759e988-bd862e3fe1be46a994272793',
+      additional_key: 'additional_value',
+    });
   });
 
   // #region format errors

packages/logger/tests/unit/initializeLogger.test.ts

@@ -151,9 +151,9 @@ describe('Log levels', () => {
         {
           level: 'INFO',
           message: 'Hello, world!',
-          sampling_rate: 0,
-          service: 'hello-world',
           timestamp: '2016-06-20T12:08:10.000Z',
+          service: 'hello-world',
+          sampling_rate: 0,
           xray_trace_id: '1-abcdef12-3456abcdef123456abcdef12',
         },
         null,