Add koaBunyanLogger.timeContext(opts) (#41977)

https://github.com/koajs/bunyan-logger#koabunyanloggertimecontextopts

> koaBunyanLogger.timeContext(opts)
> Adds time(label) and timeEnd(label) methods to the koa context, which records the time between the time() and timeEnd() calls for a given label.
>
> Calls to time() and timeEnd() can be nested or interleaved as long as they're balanced for each label.
>
> Options:
>
> logLevel: name of log level to use; defaults to 'trace'
> updateLogFields: function which will be called with arguments (fields) in koa context; can update fields or return a new object.

types/koa-bunyan-logger/index.d.ts

@@ -39,8 +39,14 @@ declare namespace koaBunyanLogger {
         ignorePath?: string[];
     }
 
+    interface TimeContextOptions {
+        logLevel?: string;
+        updateLogFields?: (fields: any) => any;
+    }
+
     function requestLogger(opts?: RequestLoggerOptions): Middleware;
     function requestIdContext(opts?: RequestIdContextOptions): Middleware;
+    function timeContext(opts?: TimeContextOptions): Middleware;
 }
 
 // Extend the Koa context to add the logger..

types/koa-bunyan-logger/koa-bunyan-logger-tests.ts

@@ -6,6 +6,20 @@ app.use(koaBunyanLogger());
 app.use(koaBunyanLogger.requestIdContext());
 app.use(koaBunyanLogger.requestLogger());
 app.use(koaBunyanLogger.requestLogger({ ignorePath: ['/ping'] }));
+app.use(koaBunyanLogger.timeContext());
+app.use(
+    koaBunyanLogger.timeContext({
+        logLevel: 'warn',
+        updateLogFields(fields) {
+            return {
+                request_trace: {
+                    name: fields.label,
+                    time: fields.duration,
+                },
+            };
+        },
+    }),
+);
 
 app.use(async (ctx, next) => {
     ctx.log.info('Got a request from %s for %s', ctx.request.ip, ctx.path);