fixup: bucketName source + error if no key field

lib/api/api.js

@@ -217,9 +217,13 @@ const api = {
 
                     formDataParser.on('file', (fieldname, file, filename, encoding, mimetype) => {
                         fileEventData = { fieldname, file, filename, encoding, mimetype };
-                        return next(null);
+                        // no key field == error
+                        if ('key' in request.formData) {
+                            return next(null);
+                        }
+                        return next(errors.InvalidArgument.customizeDescription('Bucket POST must contain'
+                            + " a field named 'key'.  If it is specified, please check the order of the fields."));
                     });
-
                     formDataParser.on('finish', () => {
                         // No file field == error
                         if (!fileEventData) {

lib/api/objectPost.js

@@ -37,14 +37,16 @@ function objectPost(authInfo, request, streamingV4Params, log, callback) {
     const {
         headers,
         method,
+        formData,
+        bucketName,
     } = request;
     let parsedContentLength = 0;
     const passThroughStream = new PassThrough();
     const requestType = request.apiMethods || 'objectPost';
     const valParams = {
         authInfo,
-        bucketName: request.formData.bucket,
-        objectKey: request.formData.key,
+        bucketName,
+        objectKey: formData.key,
         requestType,
         request,
     };

tests/functional/aws-node-sdk/test/object/post.js

@@ -388,6 +388,54 @@ describe('POST object', () => {
         });
     });
 
+    it('should handle error when key is missing', done => {
+        const { bucketName, url } = testContext;
+        // Prep fields then remove the key field
+        let fields = calculateFields(ak, sk, bucketName);
+        fields = fields.filter(e => e.name !== 'key');
+
+        const formData = new FormData();
+
+        fields.forEach(field => {
+            formData.append(field.name, field.value);
+        });
+
+        formData.append('file', fs.createReadStream(path.join(__dirname, filename)));
+
+        formData.getLength((err, length) => {
+            if (err) {
+                return done(err);
+            }
+
+            return axios.post(url, formData, {
+                headers: {
+                    ...formData.getHeaders(),
+                    'Content-Length': length,
+                },
+            })
+                .then(() => {
+                    done(new Error('Request should not succeed without key field'));
+                })
+                .catch(err => {
+                    assert.ok(err.response, 'Error should be returned by axios');
+
+                    // Parse the XML error response
+                    xml2js.parseString(err.response.data, (err, result) => {
+                        if (err) {
+                            return done(err);
+                        }
+
+                        const error = result.Error;
+                        assert.equal(error.Code[0], 'InvalidArgument');
+                        assert.equal(error.Message[0],
+                            'Bucket POST must contain a field named '
+                            + "'key'.  If it is specified, please check the order of the fields.");
+                        return done();
+                    });
+                });
+        });
+    });
+
     it('should upload an object with key slash', done => {
         const { bucketName, url } = testContext;
         const slashKey = '/';