storage: detect contentType from upload()

lib/storage/bucket.js

@@ -22,6 +22,7 @@
 
 var extend = require('extend');
 var fs = require('fs');
+var mime = require('mime');
 var path = require('path');
 
 /**
@@ -300,6 +301,17 @@ Bucket.prototype.upload = function(localPath, destination, metadata, callback) {
     newFile = destination;
   }
   newFile = newFile || this.file(name);
+
+  var contentType = mime.lookup(localPath);
+  if (contentType && !metadata.contentType) {
+    metadata.contentType = contentType;
+  }
+
+  var charset = mime.charsets.lookup(metadata.contentType);
+  if (charset) {
+    metadata.contentType += '; charset=' + charset;
+  }
+
   fs.createReadStream(localPath)
     .pipe(newFile.createWriteStream(metadata))
     .on('error', callback)

package.json

@@ -47,6 +47,7 @@
     "duplexify": "^3.1.2",
     "extend": "^1.3.0",
     "gapitoken": "^0.1.3",
+    "mime": "^1.2.11",
     "node-uuid": "^1.4.1",
     "protobufjs": "^3.4.0",
     "request": "^2.39.0",

test/storage/bucket.js

@@ -263,6 +263,7 @@ describe('Bucket', function() {
   describe('upload', function() {
     var basename = 'proto_query.json';
     var filepath = 'test/testdata/' + basename;
+    var textFilepath = 'test/testdata/textfile.txt';
     var metadata = { a: 'b', c: 'd' };
 
     beforeEach(function() {
@@ -334,6 +335,46 @@ describe('Bucket', function() {
       });
     });
 
+    it('should guess at the content type', function(done) {
+      var fakeFile = new FakeFile(bucket, 'file-name');
+      fakeFile.createWriteStream = function(metadata) {
+        var dup = duplexify();
+        setImmediate(function() {
+          assert.equal(metadata.contentType, 'application/json');
+          done();
+        });
+        return dup;
+      };
+      bucket.upload(filepath, fakeFile, assert.ifError);
+    });
+
+    it('should guess at the charset', function(done) {
+      var fakeFile = new FakeFile(bucket, 'file-name');
+      fakeFile.createWriteStream = function(metadata) {
+        var dup = duplexify();
+        setImmediate(function() {
+          assert.equal(metadata.contentType, 'text/plain; charset=UTF-8');
+          done();
+        });
+        return dup;
+      };
+      bucket.upload(textFilepath, fakeFile, assert.ifError);
+    });
+
+    it('should allow overriding content type', function(done) {
+      var fakeFile = new FakeFile(bucket, 'file-name');
+      var metadata = { contentType: 'made-up-content-type' };
+      fakeFile.createWriteStream = function(meta) {
+        var dup = duplexify();
+        setImmediate(function() {
+          assert.equal(meta.contentType,  metadata.contentType);
+          done();
+        });
+        return dup;
+      };
+      bucket.upload(filepath, fakeFile, metadata, assert.ifError);
+    });
+
     it('should execute callback on error', function(done) {
       var error = new Error('Error.');
       var fakeFile = new FakeFile(bucket, 'file-name');

test/testdata/textfile.txt

@@ -0,0 +1 @@
+This is a test file!