[now dev] Use pcre-to-regexp to match routes (#2027)

* [now dev] Use `pcre-to-regexp` to match `routes`

The now.json `routes` support PCRE syntax like named captures,
so use the `pcre-to-regexp` module to match the routes.

Fixes #2023.

* Pass the resolved router `dest` and query params to the Lambda

@types/pcre-to-regexp/index.d.ts

@@ -0,0 +1,3 @@
+declare module 'pcre-to-regexp' {
+  export default function (pattern: string, keys?: string[]): RegExp
+}

package.json

@@ -208,6 +208,7 @@
     "npm-package-arg": "6.1.0",
     "nyc": "13.2.0",
     "ora": "1.3.0",
+    "pcre-to-regexp": "0.0.4",
     "pkg": "4.3.7",
     "pluralize": "7.0.0",
     "pre-commit": "1.2.2",

src/commands/dev/lib/dev-router.ts

@@ -1,5 +1,6 @@
 import url from 'url';
 import qs from 'querystring';
+import PCRE from 'pcre-to-regexp';
 
 import isURL from './is-url';
 
@@ -12,12 +13,39 @@ export default function(reqPath = '', routes?: RouteConfig[]): RouteResult {
   // try route match
   if (routes) {
     routes.find((routeConfig: RouteConfig, idx: number) => {
-      const matcher = new RegExp('^' + routeConfig.src + '$');
+      let { src } = routeConfig;
 
-      if (matcher.test(reqPathname)) {
-        const destPath = routeConfig.dest
-          ? reqPathname.replace(matcher, routeConfig.dest)
-          : reqPathname;
+      if (!src.startsWith('^')) {
+        src = `^${src}`;
+      }
+
+      if (!src.endsWith('$')) {
+        src = `${src}$`;
+      }
+
+      const keys: string[] = [];
+      const matcher = PCRE(`%${src}%i`, keys);
+      const match = matcher.exec(reqPathname);
+
+      if (match) {
+        let destPath: string = reqPathname;
+        if (routeConfig.dest) {
+          destPath = routeConfig.dest.replace(
+            /\$([1-9a-zA-Z]+)/g,
+            (_, param) => {
+              let matchIndex: number = keys.indexOf(param);
+              if (matchIndex === -1) {
+                // It's a number match, not a named capture
+                matchIndex = parseInt(param, 10);
+              } else {
+                // For named captures, add one to the `keys` index to
+                // match up with the RegExp group matches
+                matchIndex++;
+              }
+              return match[matchIndex];
+            }
+          );
+        }
 
         if (isURL(destPath)) {
           found = {

src/commands/dev/lib/dev-server.ts

@@ -316,10 +316,14 @@ export default class DevServer {
         }
 
         const body = await rawBody(req);
+        let path: string = dest;
+        if (Object.keys(uri_args || {}).length > 0) {
+          path += `?${qs.stringify(uri_args)}`;
+        }
 
         const payload: InvokePayload = {
           method: req.method || 'GET',
-          path: req.url || '/',
+          path,
           headers: req.headers,
           encoding: 'base64',
           body: body.toString('base64')

test/dev-router.unit.js

@@ -36,7 +36,7 @@ test('[dev-router] captured groups', t => {
 
 test('[dev-router] named groups', t => {
   const routesConfig = [
-    { src: '/user/(?<id>.+)', dest: '/user.js?id=$<id>' }
+    { src: '/user/(?<id>.+)', dest: '/user.js?id=$id' }
   ];
   const result = devRouter('/user/123', routesConfig);
 

yarn.lock

@@ -5448,6 +5448,11 @@ path-type@^3.0.0:
   dependencies:
     pify "^3.0.0"
 
+pcre-to-regexp@0.0.4:
+  version "0.0.4"
+  resolved "https://registry.yarnpkg.com/pcre-to-regexp/-/pcre-to-regexp-0.0.4.tgz#a19c3fc6af540349f915367a4776c75c651dae05"
+  integrity sha1-oZw/xq9UA0n5FTZ6R3bHXGUdrgU=
+
 pend@~1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/pend/-/pend-1.2.0.tgz#7a57eb550a6783f9115331fcf4663d5c8e007a50"