Convert from generator to promise.

Updated README and tests

Working unit tests. Removed redundant promise wrapper.

Revert version number. Yield instead of thenning in unit tests.

closes #3

README.md

@@ -24,17 +24,17 @@ It does not:
 
 ## API
 
-### var stats = yield* sendfile.call(this, filename)
+### sendfile(context, filename)
 
-You must pass `this` as the context. `filename` is the filename of the file.
+You must pass the koa context. `filename` is the filename of the file.
 
-`stats` is the `fs.stat()` result of the filename. If `stats` exists, that doesn't mean that a response is set - the filename could be a directory. Instead, check `if (this.status)`.
+sendfile returns a promise that resolves to the `fs.stat()` result of the filename. If sendfile() resolves, that doesn't mean that a response is set - the filename could be a directory. Instead, check `if (context.status)`.
 
 ```js
 var sendfile = require('koa-sendfile')
 
 app.use(function* (next) {
-  var stats = yield* sendfile.call(this, '/Users/jong/.bash_profile')
+  var stats = yield sendfile(this, '/Users/jong/.bash_profile')
   if (!this.status) this.throw(404)
 })
 ```

index.js

@@ -1,4 +1,3 @@
-
 var extname = require('path').extname
 var calculate = require('etag')
 var fs = require('mz/fs')
@@ -9,35 +8,37 @@ var notfound = {
   ENOTDIR: true,
 }
 
-module.exports = function* sendfile(path) {
-  var stats = yield fs.stat(path).catch(onstaterror)
-  if (!stats) return null
-  if (!stats.isFile()) return stats
+module.exports = function sendfile(ctx, path) {
+  return fs.stat(path)
+  .then(function(stats){
+    if (!stats) return null
+    if (!stats.isFile()) return stats
 
-  this.response.status = 200
-  this.response.lastModified = stats.mtime
-  this.response.length = stats.size
-  this.response.type = extname(path)
-  if (!this.response.etag) this.response.etag = calculate(stats, {
-    weak: true
-  })
+    ctx.response.status = 200
+    ctx.response.lastModified = stats.mtime
+    ctx.response.length = stats.size
+    ctx.response.type = extname(path)
+    if (!ctx.response.etag) ctx.response.etag = calculate(stats, {
+      weak: true
+    })
 
-  // fresh based solely on last-modified
-  var fresh = this.request.fresh
-  switch (this.request.method) {
-    case 'HEAD':
-      this.response.status = fresh ? 304 : 200
-      break
-    case 'GET':
-      if (fresh) {
-        this.response.status = 304
-      } else {
-        this.body = fs.createReadStream(path)
-      }
-      break
-  }
+    // fresh based solely on last-modified
+    var fresh = ctx.request.fresh
+    switch (ctx.request.method) {
+      case 'HEAD':
+        ctx.response.status = fresh ? 304 : 200
+        break
+      case 'GET':
+        if (fresh) {
+          ctx.response.status = 304
+        } else {
+          ctx.body = fs.createReadStream(path)
+        }
+        break
+    }
 
-  return stats
+    return stats
+  }, onstaterror);
 }
 
 function onstaterror(err) {

test/index.js

@@ -11,7 +11,7 @@ describe('when path is a directory', function () {
   it('should 404', function (done) {
     var app = koa()
     app.use(function* (next) {
-      var stats = yield* sendfile.call(this, __dirname)
+      var stats = yield sendfile(this, __dirname)
       assert.ok(stats)
     })
 
@@ -25,7 +25,7 @@ describe('when path does not exist', function () {
   it('should 404', function (done) {
     var app = koa()
     app.use(function* (next) {
-      var stats = yield* sendfile.call(this, __dirname + '/kljasdlkfjaklsdf')
+      var stats = yield sendfile(this, __dirname + '/kljasdlkfjaklsdf')
       assert.ok(!stats)
     })
 
@@ -42,7 +42,7 @@ describe('when path exists', function () {
       var stats, tag
       tag = fs.stat(process.cwd() + '/test/fixture.txt')
       app.use(function* (next) {
-        stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
+        stats = yield sendfile(this, process.cwd() + '/test/fixture.txt')
         assert.ok(stats)
         tag = calculate(stats, {
           weak: true
@@ -66,14 +66,13 @@ describe('when path exists', function () {
 
     it('should support weak etag 304', function (done) {
       var app = koa()
-      var stats, tag
       fs.stat(process.cwd() + '/test/fixture.txt').then(function(stat) {
-        tag = calculate(stat, {
+        var tag = calculate(stat, {
           weak: true
         })
 
         app.use(function* (next) {
-          stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
+          var stats = yield sendfile(this, process.cwd() + '/test/fixture.txt')
           assert.ok(stats)
         })
 
@@ -86,10 +85,9 @@ describe('when path exists', function () {
 
     it('should support last-modified 304', function (done) {
       var app = koa()
-      var stats
       fs.stat(process.cwd() + '/test/fixture.txt').then(function(stat) {
         app.use(function* (next) {
-          stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
+          var stats = yield sendfile(this, process.cwd() + '/test/fixture.txt')
           assert.ok(stats)
         })
 
@@ -104,7 +102,7 @@ describe('when path exists', function () {
       var app = koa()
       var stream
       app.use(function* (next) {
-        var stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
+        var stats = yield sendfile(this, process.cwd() + '/test/fixture.txt')
         assert.ok(stats)
         stream = this.body
         this.socket.emit('error', new Error('boom'))
@@ -124,8 +122,8 @@ describe('when path exists', function () {
     it('should 200', function (done) {
       var app = koa()
       app.use(function* (next) {
-        var stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
-        assert.ok(stats)
+        yield sendfile(this, process.cwd() + '/test/fixture.txt')
+        .then(assert.ok)
       })
 
       request(app.listen())
@@ -139,8 +137,8 @@ describe('when path exists', function () {
       var app = koa()
       fs.stat(process.cwd() + '/test/fixture.txt').then(function(stat) {
         app.use(function* (next) {
-          stats = yield* sendfile.call(this, process.cwd() + '/test/fixture.txt')
-          assert.ok(stats)
+          yield sendfile(this, process.cwd() + '/test/fixture.txt')
+          .then(assert.ok)
         })
 
         request(app.listen())