Merge f9ae8db into 0e2fe76

Readme.md

@@ -20,11 +20,12 @@ $ npm install koa-send
 
  - `maxage` Browser cache max-age in milliseconds. defaults to 0
  - `hidden` Allow transfer of hidden files. defaults to false
- - `root` Root directory to restrict file access
+ - [`root`](#root-path) Root directory to restrict file access
  - `gzip` Try to serve the gzipped version of a file automatically when `gzip` is supported by a client and if the requested file with `.gz` extension exists. defaults to true.
  - `format` If not `false` (defaults to `true`), format the path to serve static file servers and not require a trailing slash for directories, so that you can do both `/directory` and `/directory/`
+ - [`setHeaders`](#setheaders) Function to set custom headers on response.
 
-## Root path
+### Root path
 
   Note that `root` is required, defaults to `''` and will be resolved,
   removing the leading `/` to make the path relative and this
@@ -48,6 +49,17 @@ app.use(function *(){
 })
 ```
 
+### setHeaders
+
+The function is called as `fn(res, path, stats)`, where the arguments are:
+* `res`: the response object
+* `path`: the resolved file path that is being sent
+* `stats`: the stats object of the file that is being sent.
+
+You should only use the `setHeaders` option when you wish to edit the `Cache-Control` or `Last-Modified` headers, because doing it before is useless (it's overwritten by `send`), and doing it after is too late because the headers are already sent.
+
+If you want to edit any other header, simply set them before calling `send`.
+
 ## Example (Koa@2) with async/await
 
 ```js

index.js

@@ -49,6 +49,11 @@ function send(ctx, path, opts) {
     var hidden = opts.hidden || false;
     var format = opts.format === false ? false : true;
     var gzip = opts.gzip === false ? false : true;
+    var setHeaders = opts.setHeaders;
+
+    if (setHeaders && typeof setHeaders !== 'function') {
+      throw new TypeError('option setHeaders must be function')
+    }
 
     var encoding = ctx.acceptsEncodings('gzip', 'deflate', 'identity');
 
@@ -94,10 +99,12 @@ function send(ctx, path, opts) {
       throw err;
     }
 
+    if (setHeaders) setHeaders(ctx.res, path, stats);
+
     // stream
-    ctx.set('Last-Modified', stats.mtime.toUTCString());
     ctx.set('Content-Length', stats.size);
-    ctx.set('Cache-Control', 'max-age=' + (maxage / 1000 | 0));
+    if (!ctx.response.get('Last-Modified')) ctx.set('Last-Modified', stats.mtime.toUTCString());
+    if (!ctx.response.get('Cache-Control')) ctx.set('Cache-Control', 'max-age=' + (maxage / 1000 | 0));
     ctx.type = type(path);
     ctx.body = fs.createReadStream(path);
 

test/index.js

@@ -454,6 +454,85 @@ describe('send(ctx, file)', function(){
     .end(done);
   })
 
+  it('should set Last-Modified', function(done){
+    var app = koa();
+
+    app.use(function *(){
+      yield send(this, '/test/fixtures/user.json');
+    });
+
+    request(app.listen())
+    .get('/')
+    .expect('Last-Modified', /GMT/)
+    .end(done);
+  })
+
+  describe('with setHeaders', function() {
+    it('throws if setHeaders is not a function', function(done){
+      var app = koa();
+
+      app.use(function *(){
+        yield send(this, '/test/fixtures/user.json', {
+          setHeaders: 'foo'
+        });
+      });
+
+      request(app.listen())
+      .get('/')
+      .expect(500)
+      .end(done);
+    })
+
+    it('should not edit already set headers', function(done){
+      var app = koa();
+
+      var testFilePath = '/test/fixtures/user.json';
+      var normalizedTestFilePath = path.normalize(testFilePath);
+
+      app.use(function *(){
+        yield send(this, testFilePath, {
+          setHeaders: function(res, path, stats) {
+            assert.equal(path.substr(-normalizedTestFilePath.length), normalizedTestFilePath);
+            assert.equal(stats.size, 18);
+            assert(res);
+
+            // these can be set
+            res.setHeader('Cache-Control', 'max-age=0,must-revalidate');
+            res.setHeader('Last-Modified', 'foo')
+            // this one can not
+            res.setHeader('Content-Length', 9000)
+          }
+        });
+      });
+
+      request(app.listen())
+      .get('/')
+      .expect(200)
+      .expect('Cache-Control', 'max-age=0,must-revalidate')
+      .expect('Last-Modified', 'foo')
+      .expect('Content-Length', 18)
+      .end(done);
+    })
+
+    it('should correctly pass through regarding usual headers', function(done){
+      var app = koa();
+
+      app.use(function *(){
+        yield send(this, '/test/fixtures/user.json', {
+          setHeaders: function() {}
+        });
+      });
+
+      request(app.listen())
+      .get('/')
+      .expect(200)
+      .expect('Cache-Control', 'max-age=0')
+      .expect('Content-Length', 18)
+      .expect('Last-Modified', /GMT/)
+      .end(done);
+    })
+  })
+
   it('should cleanup on socket error', function(done){
     var app = koa();
     var stream