add(logging): Add OTel logging for counting chars (#7903)

Co-authored-by: Shnatu <snatu@google.com>

packages/core/src/telemetry/loggers.test.ts

@@ -524,7 +524,22 @@ describe('loggers', () => {
         response: {
           callId: 'test-call-id',
           responseParts: [{ text: 'test-response' }],
-          resultDisplay: undefined,
+          resultDisplay: {
+            fileDiff: 'diff',
+            fileName: 'file.txt',
+            originalContent: 'old content',
+            newContent: 'new content',
+            diffStat: {
+              model_added_lines: 1,
+              model_removed_lines: 2,
+              model_added_chars: 3,
+              model_removed_chars: 4,
+              user_added_lines: 5,
+              user_removed_lines: 6,
+              user_added_chars: 7,
+              user_removed_chars: 8,
+            },
+          },
           error: undefined,
           errorType: undefined,
         },
@@ -560,7 +575,16 @@ describe('loggers', () => {
           tool_type: 'native',
           error: undefined,
           error_type: undefined,
-          metadata: undefined,
+          metadata: {
+            model_added_lines: 1,
+            model_removed_lines: 2,
+            model_added_chars: 3,
+            model_removed_chars: 4,
+            user_added_lines: 5,
+            user_removed_lines: 6,
+            user_added_chars: 7,
+            user_removed_chars: 8,
+          },
         },
       });
 

packages/core/src/telemetry/types.ts

@@ -165,8 +165,12 @@ export class ToolCallEvent implements BaseTelemetryEvent {
         this.metadata = {
           model_added_lines: diffStat.model_added_lines,
           model_removed_lines: diffStat.model_removed_lines,
+          model_added_chars: diffStat.model_added_chars,
+          model_removed_chars: diffStat.model_removed_chars,
           user_added_lines: diffStat.user_added_lines,
           user_removed_lines: diffStat.user_removed_lines,
+          user_added_chars: diffStat.user_added_chars,
+          user_removed_chars: diffStat.user_removed_chars,
         };
       }
     }