Check if properRoute is found before acting on it (#73)

* Check if properRoute is found before acting on it

In the cases where the request route is not matched to any Koa route,
bail out before trying to format the path string.

Issue: #59

* Add test for koa middleware unmatched route scenario

Issue: #59

* Add integration test for wildcard path scenario

Issue: #59

src/koa-middleware.js

@@ -33,7 +33,7 @@ class KoaMiddleware {
         }
     }
 
-    _handleResponse (ctx) {
+    _handleResponse(ctx) {
         const responseLength = parseInt(ctx.response.get('Content-Length')) || 0;
 
         const route = this._getRoute(ctx) || 'N/A';
@@ -93,6 +93,12 @@ class KoaMiddleware {
             }
         });
 
+        // If proper route is not found, send an undefined route
+        // The caller is responsible for setting a default "N/A" route in this case
+        if (!properRoute) {
+            return undefined;
+        }
+
         let route = properRoute.path;
         route = route.endsWith('/') ? route.substring(0, route.length - 1) : route;
         return route;

test/integration-tests/koa/middleware-test.js

@@ -679,6 +679,23 @@ describe('when using koa framework', () => {
                     });
             });
         });
+        describe('when calling wildcard endpoint', function () {
+            before(() => {
+                const wildcardPath = '/wild-path/' + Math.floor(Math.random() * 10);
+                return supertest(app)
+                    .get(wildcardPath)
+                    .expect(200)
+                    .then((res) => {});
+            });
+            it('should add it to the histogram', () => {
+                return supertest(app)
+                    .get('/metrics')
+                    .expect(200)
+                    .then((res) => {
+                        expect(res.text).to.contain('method="GET",route="N/A",code="200"');
+                    });
+            });
+        });
         it('should get metrics as json', () => {
             return supertest(app)
                 .get('/metrics.json')

test/integration-tests/koa/server/koa-server.js

@@ -78,4 +78,10 @@ router.post('/test', async (ctx, next) => {
     return next();
 });
 
+router.get('/wild-path/(.*)', (ctx, next) => {
+    ctx.status = 200;
+    ctx.body = { message: 'Wildcard route reached!' };
+    return next();
+});
+
 module.exports = app;

test/unit-test/metric-middleware-koa-test.js

@@ -653,6 +653,57 @@ describe('metrics-middleware', () => {
                 Prometheus.register.clear();
             });
         });
+        describe('when using middleware request and path not matched to any specific route', () => {
+            let match, func, req, res, ctx, next, requestSizeObserve, requestTimeObserve, endTimerStub;
+            before(async () => {
+                match = sinon.stub();
+                match.onFirstCall().returns({ path: [] });
+                match.onSecondCall().returns({ path: [{ path: '/(.*)' }] });
+                next = sinon.stub();
+                req = httpMocks.createRequest({
+                    url: '/not-path',
+                    method: 'GET',
+                    body: {
+                        foo: 'bar'
+                    },
+                    headers: {
+                        'content-length': '25'
+                    }
+                });
+                req.socket = {};
+                res = httpMocks.createResponse({
+                    eventEmitter: EventEmitter
+                });
+                res.statusCode = 404;
+                ctx = { req: req, res: res, request: req, response: res, router: { match: match }, _matchedRoute: '/(.*)', originalUrl: '/not-path' };
+                func = await middleware();
+                endTimerStub = sinon.stub();
+                requestTimeObserve = sinon.stub(Prometheus.register.getSingleMetric('http_request_duration_seconds'), 'startTimer').returns(endTimerStub);
+                func(ctx, next);
+                requestSizeObserve = sinon.spy(Prometheus.register.getSingleMetric('http_request_size_bytes'), 'observe');
+                res.emit('finish');
+            });
+            it('should update the histogram with the elapsed time and size', () => {
+                sinon.assert.calledWithExactly(requestSizeObserve, {
+                    method: 'GET',
+                    route: 'N/A',
+                    code: 404
+                }, 25);
+                sinon.assert.called(requestTimeObserve);
+                sinon.assert.calledWith(endTimerStub, {
+                    method: 'GET',
+                    route: 'N/A',
+                    code: 404
+                });
+                sinon.assert.calledOnce(requestTimeObserve);
+                sinon.assert.calledOnce(endTimerStub);
+            });
+            after(() => {
+                requestSizeObserve.restore();
+                requestTimeObserve.restore();
+                Prometheus.register.clear();
+            });
+        });
         describe('when _getConnections called', () => {
             let Middleware, server, numberOfConnectionsGauge, koaMiddleware, prometheusStub;
             before(() => {