fix: truncate additional fields set by winston/bunyan (#609)

Author: Benjamin E. Coe

handwritten/logging/package.json

@@ -58,6 +58,7 @@
     "@google-cloud/promisify": "^1.0.0",
     "@opencensus/propagation-stackdriver": "0.0.17",
     "arrify": "^2.0.0",
+    "dot-prop": "^5.1.0",
     "eventid": "^0.1.2",
     "extend": "^3.0.2",
     "gcp-metadata": "^3.1.0",

handwritten/logging/src/log.ts

@@ -14,9 +14,10 @@
  * limitations under the License.
  */
 
+import arrify = require('arrify');
 import {DeleteCallback} from '@google-cloud/common';
 import {callbackifyAll} from '@google-cloud/promisify';
-import arrify = require('arrify');
+import * as dotProp from 'dot-prop';
 import * as extend from 'extend';
 import {CallOptions} from 'google-gax';
 import {Response} from 'teeny-request';
@@ -886,27 +887,33 @@ class Log implements LogSeverityFunctions {
       const payloadSize = JSON.stringify(entry).length;
       if (payloadSize < this.maxEntrySize) return;
 
-      const delta = payloadSize - this.maxEntrySize;
+      let delta = payloadSize - this.maxEntrySize;
       if (entry.textPayload) {
         entry.textPayload = entry.textPayload.slice(
           0,
           Math.max(entry.textPayload.length - delta, 0)
         );
       } else {
-        // Stackdriver Log Viewer picks up the summary line from the
-        // 'message' field.
-        if (
-          entry.jsonPayload &&
-          entry.jsonPayload.fields &&
-          entry.jsonPayload.fields.message &&
-          entry.jsonPayload.fields.message.stringValue
-        ) {
-          const text: string | null | undefined =
-            entry.jsonPayload.fields.message.stringValue;
-          entry.jsonPayload.fields.message.stringValue = text.slice(
-            0,
-            Math.max(text.length - delta, 0)
-          );
+        const fieldsToTruncate = [
+          // Winston:
+          'jsonPayload.fields.metadata.structValue.fields.stack.stringValue',
+          // Bunyan:
+          'jsonPayload.fields.msg.stringValue',
+          'jsonPayload.fields.err.structValue.fields.stack.stringValue',
+          'jsonPayload.fields.err.structValue.fields.message.stringValue',
+          // All:
+          'jsonPayload.fields.message.stringValue',
+        ];
+        for (const field of fieldsToTruncate) {
+          const msg: string = dotProp.get(entry, field, '');
+          if (msg !== '') {
+            dotProp.set(
+              entry,
+              field,
+              msg.slice(0, Math.max(msg.length - delta, 0))
+            );
+            delta -= Math.min(msg.length, delta);
+          }
         }
       }
     });

handwritten/logging/test/log.ts

@@ -499,6 +499,34 @@ describe('Log', () => {
 
       await truncatingLogger.write(entry);
     });
+
+    it('should truncate stack trace', async () => {
+      const truncatingLogger = createLogger(300);
+      const entry = new Entry(
+        {},
+        {
+          message: 'hello world'.padEnd(2000, '.'),
+          metadata: {
+            stack: 'hello world'.padEnd(2000, '.'),
+          },
+        }
+      );
+
+      truncatingLogger.logging.loggingService.writeLogEntries = (
+        reqOpts,
+        _gaxOpts
+      ) => {
+        const message =
+          reqOpts.entries[0].jsonPayload.fields.message.stringValue;
+        const stack = reqOpts.entries[0].jsonPayload.fields.metadata
+          .structValue!.fields!.stack.stringValue;
+        assert.strictEqual(stack, '');
+        assert.ok(message.startsWith('hello world'));
+        assert.ok(message.length < 400);
+      };
+
+      await truncatingLogger.write(entry);
+    });
   });
 
   describe('severity shortcuts', () => {