New "browse" UI

Also, separated out browse, ?meta, and ?module request handlers.

Fixes #82

modules/__tests__/browseDirectory-test.js

@@ -2,7 +2,7 @@ import request from 'supertest';
 
 import createServer from '../createServer.js';
 
-describe('A request that targets a directory with a trailing slash', () => {
+describe('A request to browse a directory', () => {
   let server;
   beforeEach(() => {
     server = createServer();
@@ -11,7 +11,7 @@ describe('A request that targets a directory with a trailing slash', () => {
   describe('when the directory exists', () => {
     it('returns an HTML page', done => {
       request(server)
-        .get('/react@16.8.0/umd/')
+        .get('/browse/react@16.8.0/umd/')
         .end((err, res) => {
           expect(res.statusCode).toBe(200);
           expect(res.headers['content-type']).toMatch(/\btext\/html\b/);
@@ -21,12 +21,12 @@ describe('A request that targets a directory with a trailing slash', () => {
   });
 
   describe('when the directory does not exist', () => {
-    it('returns a 404 text error', done => {
+    it('returns a 404 HTML page', done => {
       request(server)
-        .get('/react@16.8.0/not-here/')
+        .get('/browse/react@16.8.0/not-here/')
         .end((err, res) => {
           expect(res.statusCode).toBe(404);
-          expect(res.headers['content-type']).toMatch(/\btext\/plain\b/);
+          expect(res.headers['content-type']).toMatch(/\btext\/html\b/);
           done();
         });
     });

modules/__tests__/browseFile-test.js

@@ -0,0 +1,34 @@
+import request from 'supertest';
+
+import createServer from '../createServer.js';
+
+describe('A request to browse a file', () => {
+  let server;
+  beforeEach(() => {
+    server = createServer();
+  });
+
+  describe('when the file exists', () => {
+    it('returns an HTML page', done => {
+      request(server)
+        .get('/browse/react@16.8.0/umd/react.production.min.js')
+        .end((err, res) => {
+          expect(res.statusCode).toBe(200);
+          expect(res.headers['content-type']).toMatch(/\btext\/html\b/);
+          done();
+        });
+    });
+  });
+
+  describe('when the file does not exist', () => {
+    it('returns a 404 HTML page', done => {
+      request(server)
+        .get('/browse/react@16.8.0/not-here.js')
+        .end((err, res) => {
+          expect(res.statusCode).toBe(404);
+          expect(res.headers['content-type']).toMatch(/\btext\/html\b/);
+          done();
+        });
+    });
+  });
+});

modules/__tests__/legacyURLs-test.js

@@ -27,4 +27,14 @@ describe('Legacy URLs', () => {
         done();
       });
   });
+
+  it('redirect */ to /browse/*/', done => {
+    request(server)
+      .get('/react@16.8.0/umd/')
+      .end((err, res) => {
+        expect(res.statusCode).toBe(302);
+        expect(res.headers.location).toEqual('/browse/react@16.8.0/umd/');
+        done();
+      });
+  });
 });