Initial addition of koa-route plugin

src/plugins/koa.js

@@ -8,6 +8,9 @@ function createWrapUse (tracer, config) {
   function ddTrace (ctx, next) {
     web.instrument(tracer, config, ctx.req, ctx.res, 'koa.request')
 
+    web.beforeEnd(ctx.req, () => {
+      web.enterRoute(ctx.req, ctx.routePath)
+    })
     return next()
   }
 

src/plugins/util/web.js

@@ -68,7 +68,9 @@ const web = {
 
   // Add a route segment that will be used for the resource name.
   enterRoute (req, path) {
-    req._datadog.paths.push(path)
+    if (typeof path === 'string') {
+      req._datadog.paths.push(path)
+    }
   },
 
   // Remove the current route segment.

test/plugins/externals.json

@@ -16,6 +16,10 @@
     }
   ],
   "koa": [
+    {
+      "name": "koa-route",
+      "versions": [">=3.2"]
+    },
     {
       "name": "koa-websocket",
       "versions": ["5.0.1"]

test/plugins/koa.spec.js

@@ -215,6 +215,41 @@ describe('Plugin', () => {
           })
         })
 
+        withVersions(plugin, 'koa-route', routerVersion => {
+          let koaRouter
+
+          beforeEach(() => {
+            koaRouter = require(`../../versions/koa-route@${routerVersion}`).get()
+          })
+
+          it('should do automatic instrumentation on koa-route', done => {
+            const app = new Koa()
+
+            const getUser = (ctx, id) => {
+              ctx.body = ''
+            }
+
+            app
+              .use(koaRouter.get('/user/:id', getUser))
+
+            agent
+              .use(traces => {
+                const spans = sort(traces[0])
+
+                expect(spans[0]).to.have.property('resource', 'GET /user/:id')
+                expect(spans[0].meta).to.have.property('http.url', `http://localhost:${port}/user/123`)
+              })
+              .then(done)
+              .catch(done)
+
+            appListener = app.listen(port, 'localhost', (e) => {
+              axios
+                .get(`http://localhost:${port}/user/123`)
+                .catch(done)
+            })
+          })
+        })
+
         withVersions(plugin, 'koa-router', routerVersion => {
           let Router
 
@@ -237,7 +272,6 @@ describe('Plugin', () => {
             agent
               .use(traces => {
                 const spans = sort(traces[0])
-
                 expect(spans[0]).to.have.property('resource', 'GET /user/:id')
                 expect(spans[0].meta).to.have.property('http.url', `http://localhost:${port}/user/123`)
 

test/plugins/util/web.spec.js

@@ -390,6 +390,17 @@ describe('plugins/util/web', () => {
       expect(span.context()._tags).to.have.property(RESOURCE_NAME, 'GET /foo/bar')
       expect(span.context()._tags).to.have.property(HTTP_ROUTE, '/foo/bar')
     })
+
+    it('should only add valid route segments to the span resource name', () => {
+      req.method = 'GET'
+
+      web.enterRoute(req)
+      web.enterRoute(req, 1337)
+      res.end()
+
+      expect(span.context()._tags).to.have.property(RESOURCE_NAME, 'GET')
+      expect(span.context()._tags).to.not.have.property(HTTP_ROUTE)
+    })
   })
 
   describe('exitRoute', () => {