Koa module code level visibility

demo/koa-example/index.js

@@ -0,0 +1,17 @@
+'use strict'
+
+const Koa = require('koa')
+const Router = require('@koa/router')
+
+const app = new Koa()
+const router = new Router()
+
+router.get('/', (ctx, next) => {
+    ctx.body = 'Hello World'
+})
+
+app
+    .use(router.routes())
+    .use(router.allowedMethods())
+
+app.listen(1234)

demo/koa-example/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "koa-example",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@koa/router": "^10.0.0",
+    "koa": "^2.13.1"
+  }
+}

lib/context/koa-method-descriptor-builder.js

@@ -0,0 +1,18 @@
+/**
+ * Pinpoint Node.js Agent
+ * Copyright 2022-present NAVER Corp.
+ * Apache License v2.0
+ */
+
+'use strict'
+
+class KoaMethodDescriptorBuilder {
+    static make(builder) {
+        if (!builder) {
+            return
+        }
+        return builder.setParameterDescriptor('(ctx, next)')
+    }
+}
+
+module.exports = KoaMethodDescriptorBuilder

lib/context/method-descriptor-builder.js

@@ -214,6 +214,9 @@ function makeFunctionName(namedGroup) {
     if (computedGroups && computedGroups.length > 0 && namedGroup.methodName) {
         return computedGroups.groups.functionName + namedGroup.methodName
     }
+    if (functionName === '<computed>' && typeof namedGroup.type === 'string' && typeof namedGroup.methodName === 'string') {
+        return namedGroup.methodName
+    }
     return namedGroup.functionName
 }
 

lib/instrumentation/module-hook.js

@@ -15,7 +15,6 @@ const MODULES = [
   'express',
   'http',
   'https',
-  // 'koa',
   'koa-router',
   'redis',
   'ioredis',
@@ -67,8 +66,8 @@ class ModuleHook {
       } catch (error) {
         log.error('error occurred', error)
       }
-    } 
-    
+    }
+
     if (!version) {
       version = process.versions.node
     }

lib/instrumentation/module/koa-router.js

@@ -10,70 +10,80 @@ const semver = require('semver')
 const shimmer = require('shimmer')
 const ServiceTypeCode = require('../../constant/service-type').ServiceTypeCode
 const log = require('../../utils/logger')
-const MethodDescriptor = require('../../context/method-descriptor')
+const layerPatchedSymbol = Symbol('PinpointKoaLayerPatched')
+const { makeMethodDescriptorBuilder } = require('../../context/make-method-descriptor-builder')
+const KoaMethodDescriptorBuilder = require('../../context/koa-method-descriptor-builder')
 const apiMetaService = require('../../context/api-meta-service')
 
-module.exports = function(agent, version, router) {
+module.exports = function (agent, version, router) {
   if (!semver.satisfies(version, '>=5.2.0 <8')) {
     log.debug('koa-router version %s not supported - aborting...', version)
     return router
   }
 
-  const methodDescriptorMap = new Map()
+  shimmer.wrap(router.prototype, 'register', function (original) {
+    return function (path, methods, middleware, opts) {
+      const layer = original.apply(this, arguments)
 
-  const MODULE_NAME = 'koa'
-  const OBJECT_NAME = 'router'
+      if (layer[layerPatchedSymbol]) {
+        return layer
+      }
 
-  function getMethodDescriptor (methodName) {
-    return methodDescriptorMap.get(methodName)|| setMethodDescriptor(methodName)
-  }
+      layer[layerPatchedSymbol] = true
 
-  function setMethodDescriptor(methodName) {
-    const descriptor = MethodDescriptor.create(MODULE_NAME, OBJECT_NAME, methodName)
-    apiMetaService.cacheApi(descriptor)
-    methodDescriptorMap.set(methodName, descriptor)
-    return descriptor
-  }
+      if (!Array.isArray(layer.stack) || layer.stack.length < 1) {
+        return layer
+      }
 
-    shimmer.wrap(router.prototype, 'register', function(original) {
-    return function (path, methods, middleware, opts) {
-      const layer = original.apply(this, arguments)
-      if (layer.stack) {
-        layer.stack.forEach((fn, index) => {
-          if (typeof fn === 'function') {
-            let result
-            layer.stack[index] = async function(ctx, next) {
-              const name = fn.name || 'AnonymousFunction'
-              const trace = agent.traceContext.currentTraceObject()
-              let spanEventRecorder = null
-              try {
-                if (trace) {
-                  spanEventRecorder = trace.traceBlockBegin()
-                  spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-                  spanEventRecorder.recordApiDesc(`koa.router.${ctx.method.toLocaleLowerCase()} [${name}]`)
-                }
-                result = await fn.apply(this, arguments)
-              } catch (e) {
-                if (!e._pinpointCheck) {
-                  e._pinpointCheck = true
-                  spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-                  spanEventRecorder.recordApiDesc(`koa.router.${ctx.method.toLocaleLowerCase()} [${name}]`)
-                  spanEventRecorder.recordException(e, true)
-                }
-                throw e
-              } finally {
-                if (trace) {
-                  trace.traceBlockEnd(spanEventRecorder)
-                }
-              }
-              return result
-            }
+      const handlerIndex = layer.stack.length - 1
+      const fn = layer.stack[handlerIndex]
+      if (typeof fn !== 'function') {
+        return layer
+      }
+
+      const builder = KoaMethodDescriptorBuilder.make(makeMethodDescriptorBuilder('koa', 2, 3))
+      const methodDescriptor = apiMetaService.cacheApiWithBuilder(builder)
+      layer.stack[handlerIndex] = async function (ctx, next) {
+        const name = fn.name || 'AnonymousFunction'
+        const trace = agent.traceContext.currentTraceObject()
+        let spanEventRecorder = null
+        let result
+        try {
+          if (trace) {
+            spanEventRecorder = trace.traceBlockBegin()
+            spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
+            recordAPI(methodDescriptor, path, spanEventRecorder, ctx, name)
+          }
+          result = await fn.apply(this, arguments)
+        } catch (e) {
+          if (!e._pinpointCheck) {
+            e._pinpointCheck = true
+            spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
+            recordAPI(methodDescriptor, path, spanEventRecorder, ctx, name)
+            spanEventRecorder.recordException(e, true)
+          }
+          throw e
+        } finally {
+          if (trace) {
+            trace.traceBlockEnd(spanEventRecorder)
           }
-        })
+        }
+        return result
       }
       return layer
     }
   })
 
   return router
 }
+
+function recordAPI(methodDescriptor, path, spanEventRecorder, ctx, name) {
+  if (methodDescriptor && typeof path === 'string') {
+    spanEventRecorder.recordApiWithParameters(methodDescriptor, [path])
+  } else if (methodDescriptor) {
+    spanEventRecorder.recordApi(methodDescriptor)
+  } else {
+    spanEventRecorder.recordApiDesc(`koa.router.${ctx.method.toLocaleLowerCase()} [${name}]`)
+  }
+}
+

lib/instrumentation/module/koa.js

@@ -11,94 +11,6 @@ const shimmer = require('shimmer')
 const ServiceTypeCode = require('../../constant/service-type').ServiceTypeCode
 const log = require('../../utils/logger')
 
-module.exports = function(agent, version, koa) {
-
-  // todo. emit 체크
-  shimmer.wrap(koa.prototype, 'emit', function(original) {
-    return function (evt, err, ctx) {
-      const trace = agent.traceContext.currentTraceObject()
-      let spanEventRecorder = null
-      if (evt === 'error' & ctx) {
-        spanEventRecorder = trace.traceBlockBegin()
-        spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-        spanEventRecorder.recordApiDesc('koa')
-        spanEventRecorder.recordException(err, true)
-        trace.traceBlockEnd(spanEventRecorder)
-        return original.apply(this, arguments)
-      }
-      if (trace) {
-        spanEventRecorder = trace.traceBlockBegin()
-        spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-        spanEventRecorder.recordApiDesc('koa') // Todo. check this
-      }
-      const result = original.apply(this, arguments)
-      if (trace) {
-        trace.traceBlockEnd(spanEventRecorder)
-      }
-      return result
-    }
-  })
-  shimmer.wrap(koa.prototype, 'use', function(original) {
-    return function wrapMiddleware(middleware) {
-      if (typeof middleware === 'function') {
-        const cb = arguments[0]
-        const name = middleware.name || 'AnonymousFunction'
-        // todo. 기본로직을 제외 하는 방법 검토할 것
-        // if (cb.toString().trim().match(/^async/)) {}
-        arguments[0] = async function(ctx, next) {
-          let result
-          const trace = agent.traceContext.currentTraceObject()
-          let spanEventRecorder = null
-          try {
-            if (trace) {
-              spanEventRecorder = trace.traceBlockBegin()
-              spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-              spanEventRecorder.recordApiDesc(`middleware [${name}]`)
-            }
-            result = await cb.apply(this, arguments)
-          } catch (e) {
-            if (!e._pinpointCheck) {
-              e._pinpointCheck = true
-              spanEventRecorder.recordServiceType(ServiceTypeCode.koa)
-              spanEventRecorder.recordApiDesc(`middleware [${name}]`)
-              spanEventRecorder.recordException(e, true)
-            }
-            throw e
-          } finally {
-            if (trace) {
-              trace.traceBlockEnd(spanEventRecorder)
-            }
-          }
-          return result
-        }
-
-      }
-      return original.apply(this, arguments)
-    }
-  })
-  // Test 3. createContext
-  // shimmer.wrap(koa.prototype, 'createContext', function(original) {
-  //   return function wrapCreateContext(req, res) {
-  //     const result = original.apply(this, arguments)
-  //
-  //     shimmer.wrap(result, 'onerror', function(ori) {
-  //       return function (err) {
-  //         const trace = agent.traceContext.currentTraceObject()
-  //         if (trace) {
-  //           const spanEventRecorder = trace.traceBlockBegin()
-  //           spanEventRecorder.recordServiceType(ServiceTypeCode.express)
-  //           spanEventRecorder.recordApiDesc('tes')
-  //           spanEventRecorder.recordException(err, true)
-  //           trace.traceBlockEnd(spanEventRecorder)
-  //         }
-  //         return ori.apply(this, arguments)
-  //       }
-  //     })
-  //
-  //
-  //
-  //     return result
-  //   }
-  // })
+module.exports = function (agent, version, koa) {
   return koa
 }