Fix connectlogger nolog function

lib/connect-logger.js

@@ -251,12 +251,10 @@ module.exports = function getLogger(logger4js, options) {
 
   return (req, res, next) => {
     // mount safety
-    if (req._logging) return next();
+    if (req._logging !== undefined) return next();
 
     // nologs
-    if (typeof options.nolog === 'function') {
-      if (options.nolog(req, res) === true) return next();
-    } else {
+    if (typeof options.nolog !== 'function') {
       const nolog = createNoLogCondition(options.nolog);
       if (nolog && nolog.test(req.originalUrl)) return next();
     }
@@ -284,6 +282,15 @@ module.exports = function getLogger(logger4js, options) {
           return;
         }
         finished = true;
+
+        // nologs
+        if (typeof options.nolog === 'function') {
+          if (options.nolog(req, res) === true) {
+            req._logging = false;
+            return;
+          }
+        }
+
         res.responseTime = new Date() - start;
         // status code response level handling
         if (res.statusCode && options.level === 'auto') {

test/tap/configuration-validation-test.js

@@ -274,7 +274,9 @@ test('log4js configuration validation', (batch) => {
         })
       )
     );
-    t.end();
+    log4js.shutdown(() => {
+      t.end();
+    });
   });
 
   batch.test('should load appenders from core first', (t) => {

test/tap/connect-nolog-test.js

@@ -348,7 +348,10 @@ test('log4js connect logger', (batch) => {
 
   batch.test('nolog function', (t) => {
     const ml = new MockLogger();
-    const cl = clm(ml, { nolog: (_req, res) => res.statusCode < 400 });
+    const cl = clm(ml, {
+      nolog: (_req, res) =>
+        res.getHeader('content-type') === 'image/png' || res.statusCode < 400,
+    });
 
     t.beforeEach(() => {
       ml.messages = [];
@@ -381,6 +384,27 @@ test('log4js connect logger', (batch) => {
       assert.end();
     });
 
+    t.test(
+      'check match function server response content-type header',
+      (assert) => {
+        const { messages } = ml;
+        const req = new MockRequest(
+          'my.remote.addr',
+          'GET',
+          'http://url/nolog'
+        );
+        const res = new MockResponse(500);
+        res.on('finish', () => {
+          res.setHeader('content-type', 'image/png');
+        });
+        cl(req, res, () => {});
+        res.end('chunk', 'encoding');
+
+        assert.equal(messages.length, 0);
+        assert.end();
+      }
+    );
+
     t.end();
   });