fix: parse structured logs, and handle ANSI escape codes in logs

.eslintrc.json

@@ -1,3 +1,6 @@
 {
-    "extends": "./node_modules/gts"
+    "extends": "./node_modules/gts",
+    "rules": {
+        "no-control-regex": 0
+    }
 }

src/logger.ts

@@ -127,14 +127,24 @@ export function getModifiedData(
     return data;
   }
   const {isJSON, processedData} = processData(data, encoding);
-  let dataWithContext;
+
+  let dataWithContext: {
+    message: string | Uint8Array;
+    'logging.googleapis.com/labels': {execution_id: string | undefined};
+    'logging.googleapis.com/trace': string | undefined;
+    'logging.googleapis.com/spanId': string | undefined;
+    severity?: string | undefined;
+  };
   if (isJSON) {
     dataWithContext = getJSONWithContext(processedData, currentContext);
+    if (stderr && !(SEVERITY in dataWithContext)) {
+      dataWithContext[SEVERITY] = 'ERROR';
+    }
   } else {
     dataWithContext = getTextWithContext(processedData, currentContext);
-  }
-  if (stderr) {
-    dataWithContext[SEVERITY] = 'ERROR';
+    if (stderr) {
+      dataWithContext[SEVERITY] = 'ERROR';
+    }
   }
 
   return JSON.stringify(dataWithContext) + '\n';
@@ -178,6 +188,9 @@ function processData(data: Uint8Array | string, encoding?: BufferEncoding) {
     return {isJSON: false, processedData: data};
   }
 
+  // strip any leading ANSI color codes from the decoded data
+  // to parse colored JSON objects correctly
+  decodedData = decodedData.replace(/\x1b[[(?);]{0,2}(;?\d)*./g, '');
   try {
     return {isJSON: true, processedData: JSON.parse(decodedData)};
   } catch (e) {

test/logger.ts

@@ -148,4 +148,34 @@ describe('getModifiedData', () => {
       ) + '\n';
     assert.equal(modifiedData, expectedOutput);
   });
+
+  it('parses firebase warning severity and message', () => {
+    const modifiedData = <string>(
+      getModifiedData(
+        '\u001b[33m{"severity":"WARNING","message":"testing warning log level"}\u001b[39m\n',
+        undefined,
+        true
+      )
+    );
+    assert.equal('WARNING', JSON.parse(modifiedData)['severity']);
+    assert.equal(
+      'testing warning log level',
+      JSON.parse(modifiedData)['message']
+    );
+  });
+
+  it('parses firebase error severity and message', () => {
+    const modifiedData = <string>(
+      getModifiedData(
+        '\u001b[31m{"severity":"ERROR","message":"testing error log level"}\u001b[39m\n',
+        undefined,
+        true
+      )
+    );
+    assert.equal('ERROR', JSON.parse(modifiedData)['severity']);
+    assert.equal(
+      'testing error log level',
+      JSON.parse(modifiedData)['message']
+    );
+  });
 });