refactor: add web framework plugin types and script to fetch types

.gitignore

@@ -1,7 +1,7 @@
-*.tgz
+node_modules/
+npm-debug.log
 .DS_Store
 .nyc_output/
 .vscode/
 build/
-node_modules/
-npm-debug.log
+*.tgz

package.json

@@ -50,17 +50,23 @@
   },
   "devDependencies": {
     "@google-cloud/datastore": "^1.0.2",
+    "@types/connect": "^3.4.31",
     "@types/continuation-local-storage": "^3.2.1",
+    "@types/express": "^4.11.0",
     "@types/extend": "^3.0.0",
     "@types/glob": "^5.0.32",
+    "@types/hapi": "^16.1.12",
     "@types/is": "0.0.18",
+    "@types/koa": "^2.0.43",
+    "@types/methods": "^1.1.0",
     "@types/mocha": "^2.2.44",
     "@types/ncp": "^2.0.1",
     "@types/node": "^9.3.0",
     "@types/once": "^1.4.0",
     "@types/pify": "^3.0.0",
     "@types/proxyquire": "^1.3.28",
     "@types/request": "^2.0.8",
+    "@types/restify": "^5.0.7",
     "@types/semver": "^5.4.0",
     "@types/shimmer": "^1.0.0",
     "@types/tmp": "0.0.33",

scripts/utils.ts

@@ -1,4 +1,4 @@
-import { Stats, stat, readFile, writeFile, mkdir } from 'fs';
+import { mkdir, Stats, stat, readFile, writeFile } from 'fs';
 import * as glob from 'glob';
 import { ncp } from 'ncp';
 import * as path from 'path';
@@ -21,6 +21,10 @@ export function nodule(nodule: string) {
   return path.relative(BUILD_DIRECTORY, `node_modules/${nodule}`);
 }
 
+export function flatten<T>(arr: Array<Array<T>>): Array<T> {
+  return arr.reduce((acc, e) => acc.concat(e), []);
+}
+
 export function existsP(path: string): Promise<boolean> {
   return statP(path).then(
     () => Promise.resolve(true),

src/plugin-types.ts

@@ -72,9 +72,9 @@ export interface RootSpanOptions extends SpanOptions {
   url?: string;
   /**
    * The serialized form of an object that contains information about an
-   * existing trace context.
+   * existing trace context, if it exists.
    */
-  traceContext?: string;
+  traceContext?: string|null;
 }
 
 export interface TraceAgent {

src/plugins/plugin-connect.ts

@@ -13,26 +13,47 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-'use strict';
 
-var urlParse = require('url').parse;
+import {IncomingMessage, ServerResponse} from 'http';
+import * as shimmer from 'shimmer';
+import {parse as urlParse} from 'url';
 
-var SUPPORTED_VERSIONS = '3.x';
+import {PluginTypes} from '..';
 
-function createMiddleware(api) {
-  return function middleware(req, res, next) {
-    var options = {
-      name: urlParse(req.originalUrl).pathname,
+import {connect_3} from './types';
+
+type Connect3 = typeof connect_3;
+// Connect docs note that routed requests have an originalUrl property.
+// https://github.com/senchalabs/connect/tree/3.6.5#appuseroute-fn
+type Request = IncomingMessage&{originalUrl?: string};
+
+const SUPPORTED_VERSIONS = '3.x';
+
+function getFirstHeader(req: IncomingMessage, key: string): string|null {
+  let headerValue = req.headers[key] || null;
+  if (headerValue && typeof headerValue !== 'string') {
+    headerValue = headerValue[0];
+  }
+  return headerValue;
+}
+
+function createMiddleware(api: PluginTypes.TraceAgent):
+    connect_3.NextHandleFunction {
+  return function middleware(req: Request, res, next) {
+    const options = {
+      name: req.originalUrl ? (urlParse(req.originalUrl).pathname || '') : '',
       url: req.originalUrl,
-      traceContext: req.headers[api.constants.TRACE_CONTEXT_HEADER_NAME.toLowerCase()],
+      traceContext:
+          getFirstHeader(req, api.constants.TRACE_CONTEXT_HEADER_NAME),
       skipFrames: 3
     };
-    api.runInRootSpan(options, function(root) {
+    api.runInRootSpan(options, (root) => {
       // Set response trace context.
-      var responseTraceContext =
-        api.getResponseTraceContext(options.traceContext, !!root);
+      const responseTraceContext =
+          api.getResponseTraceContext(options.traceContext || null, !!root);
       if (responseTraceContext) {
-        res.setHeader(api.constants.TRACE_CONTEXT_HEADER_NAME, responseTraceContext);
+        res.setHeader(
+            api.constants.TRACE_CONTEXT_HEADER_NAME, responseTraceContext);
       }
 
       if (!root) {
@@ -42,8 +63,8 @@ function createMiddleware(api) {
       api.wrapEmitter(req);
       api.wrapEmitter(res);
 
-      var url = (req.headers['X-Forwarded-Proto'] || 'http') +
-        '://' + req.headers.host + req.originalUrl;
+      const url = `${req.headers['X-Forwarded-Proto'] || 'http'}://${
+          req.headers.host}${req.originalUrl}`;
 
       // we use the path part of the url as the span name and add the full
       // url as a label
@@ -52,18 +73,13 @@ function createMiddleware(api) {
       root.addLabel(api.labels.HTTP_SOURCE_IP, req.connection.remoteAddress);
 
       // wrap end
-      var originalEnd = res.end;
-      res.end = function() {
+      const originalEnd = res.end;
+      res.end = function(this: ServerResponse) {
         res.end = originalEnd;
-        var returned = res.end.apply(this, arguments);
-
-        if (req.route && req.route.path) {
-          root.addLabel(
-            'connect/request.route.path', req.route.path);
-        }
+        const returned = res.end.apply(this, arguments);
 
-        root.addLabel(
-          api.labels.HTTP_RESPONSE_CODE_LABEL_KEY, res.statusCode);
+        root.addLabel('connect/request.route.path', req.originalUrl);
+        root.addLabel(api.labels.HTTP_RESPONSE_CODE_LABEL_KEY, res.statusCode);
         root.endSpan();
 
         return returned;
@@ -74,19 +90,16 @@ function createMiddleware(api) {
   };
 }
 
-module.exports = [
-  {
-    file: '',
-    versions: SUPPORTED_VERSIONS,
-    intercept: function(connect, api) {
-      return function() {
-        var app = connect();
-        app.use(createMiddleware(api));
-        return app;
-      };
-    }
+const plugin: PluginTypes.Plugin = [{
+  file: '',
+  versions: SUPPORTED_VERSIONS,
+  intercept: (connect, api) => {
+    return function(this: {}) {
+      const app = connect();
+      app.use(createMiddleware(api));
+      return app;
+    };
   }
-];
-
+} as PluginTypes.Intercept<Connect3>];
 
-export default {};
+export = plugin;

src/plugins/plugin-express.ts

@@ -14,35 +14,35 @@
  * limitations under the License.
  */
 
-'use strict';
-var shimmer = require('shimmer');
-var methods = require('methods').concat('use', 'route', 'param', 'all');
+import * as httpMethods from 'methods';
+import * as shimmer from 'shimmer';
 
-var SUPPORTED_VERSIONS = '4.x';
+import {PluginTypes} from '..';
 
-function patchModuleRoot(express, api) {
-  var labels = api.labels;
-  function applicationActionWrap(method) {
-    return function expressActionTrace() {
-      if (!this._google_trace_patched && !this._router) {
-        this._google_trace_patched = true;
-        this.use(middleware);
-      }
-      return method.apply(this, arguments);
-    };
-  }
+import {express_4} from './types';
+
+// application is an undocumented member of the express object.
+type Express4Module = typeof express_4&{application: express_4.Application};
+
+const methods = httpMethods.concat('use', 'route', 'param', 'all');
 
-  function middleware(req, res, next) {
-    var options = {
+const SUPPORTED_VERSIONS = '4.x';
+
+function patchModuleRoot(express: Express4Module, api: PluginTypes.TraceAgent) {
+  const labels = api.labels;
+  function middleware(
+      req: express_4.Request, res: express_4.Response,
+      next: express_4.NextFunction) {
+    const options: PluginTypes.RootSpanOptions = {
       name: req.path,
       traceContext: req.get(api.constants.TRACE_CONTEXT_HEADER_NAME),
       url: req.originalUrl,
       skipFrames: 3
     };
-    api.runInRootSpan(options, function(rootSpan) {
+    api.runInRootSpan(options, (rootSpan) => {
       // Set response trace context.
-      var responseTraceContext =
-        api.getResponseTraceContext(options.traceContext, !!rootSpan);
+      const responseTraceContext =
+          api.getResponseTraceContext(options.traceContext || null, !!rootSpan);
       if (responseTraceContext) {
         res.set(api.constants.TRACE_CONTEXT_HEADER_NAME, responseTraceContext);
       }
@@ -55,16 +55,16 @@ function patchModuleRoot(express, api) {
       api.wrapEmitter(req);
       api.wrapEmitter(res);
 
-      var url = req.protocol + '://' + req.hostname + req.originalUrl;
+      const url = `${req.protocol}://${req.hostname}${req.originalUrl}`;
       rootSpan.addLabel(labels.HTTP_METHOD_LABEL_KEY, req.method);
       rootSpan.addLabel(labels.HTTP_URL_LABEL_KEY, url);
       rootSpan.addLabel(labels.HTTP_SOURCE_IP, req.connection.remoteAddress);
 
       // wrap end
-      var originalEnd = res.end;
-      res.end = function() {
+      const originalEnd = res.end;
+      res.end = function(this: express_4.Response) {
         res.end = originalEnd;
-        var returned = res.end.apply(this, arguments);
+        const returned = res.end.apply(this, arguments);
 
         if (req.route && req.route.path) {
           rootSpan.addLabel('express/request.route.path', req.route.path);
@@ -78,21 +78,32 @@ function patchModuleRoot(express, api) {
     });
   }
 
-  methods.forEach(function(method) {
+  function applicationActionWrap<T extends Function>(method: T): () => T {
+    return function expressActionTrace(this: express_4.Application&
+                                       PluginTypes.TraceAgentExtension) {
+      if (!this._google_trace_patched && !this._router) {
+        this._google_trace_patched = true;
+        this.use(middleware);
+      }
+      return method.apply(this, arguments);
+    };
+  }
+
+  methods.forEach((method) => {
     shimmer.wrap(express.application, method, applicationActionWrap);
   });
 }
 
-function unpatchModuleRoot(express) {
-  methods.forEach(function(method) {
+function unpatchModuleRoot(express: Express4Module) {
+  methods.forEach((method) => {
     shimmer.unwrap(express.application, method);
   });
 }
 
-module.exports = [{
-    versions: SUPPORTED_VERSIONS,
-    patch: patchModuleRoot,
-    unpatch: unpatchModuleRoot
-}];
+const plugin: PluginTypes.Plugin = [{
+  versions: SUPPORTED_VERSIONS,
+  patch: patchModuleRoot,
+  unpatch: unpatchModuleRoot
+} as PluginTypes.Patch<Express4Module>];
 
-export default {};
+export = plugin;