Make fs.write() and fs.writeSync() consistent (#960)

Now fs.write() can accept `null` or `undefined` as `position` argument like fs.writeSync().

IoT.js-DCO-1.0-Signed-off-by: Zsolt Borbély [email protected]

Author: Zsolt Borbély

docs/api/IoT.js-API-File-System.md

@@ -571,7 +571,7 @@ fs.unlinkSync('test.txt');
 * `buffer` {Buffer} Buffer that the data will be written from.
 * `offset` {number} Offset of the buffer where from start reading.
 * `length` {number} Number of bytes to write.
-* `position` {number} Specifying where to start write data to the file.
+* `position` {number} Specifying where to start write data to the file, if `null` or `undefined`, write at the current position.
 * `callback` {Function}
   * `err` {Error|null}
   * `bytesWrite` {integer}

src/js/fs.js

@@ -164,6 +164,8 @@ fs.write = function(fd, buffer, offset, length, position, callback) {
   if (util.isFunction(position)) {
     callback = position;
     position = -1; // write at current position.
+  } else if (util.isNullOrUndefined(position)) {
+    position = -1; // write at current position.
   }
 
   callback = checkArgFunction(callback, 'callback');

test/run_pass/test_fs_write.js

@@ -0,0 +1,56 @@
+/* Copyright 2017-present Samsung Electronics Co., Ltd. and other contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var fs = require('fs');
+var assert = require('assert');
+
+var dstFilePath = process.cwd() + "/tmp/test_fs3.txt";
+var buff1 = new Buffer("IoT");
+var buff2 = new Buffer(".js");
+
+fs.open(dstFilePath, 'w+', function(err, fd) {
+  if (err) {
+    throw err;
+  }
+
+  // Test the position argument of fs.write().
+  fs.write(fd, buff1, 0, buff1.length, undefined, function(err, bytes, buffer) {
+    if (err) {
+      throw err;
+    }
+
+    fs.write(fd, buff2, 0, buff2.length, null, function(err, bytes, buffer) {
+      if (err) {
+        throw err;
+      }
+
+      // Check the result.
+      var result = new Buffer(6);
+      fs.read(fd, result, 0, result.length, 0, function(err, bytes, buffer) {
+        if (err) {
+          throw err;
+        }
+        var init_buffers = Buffer.concat([buff1, buff2]);
+        assert.assert(result.equals(init_buffers));
+
+        fs.close(fd, function(err) {
+          if (err) {
+            throw err;
+          }
+        });
+      });
+    });
+  });
+});

test/testsets.json

@@ -32,6 +32,7 @@
     { "name": "test_fs_rename.js" },
     { "name": "test_fs_rename_sync.js" },
     { "name": "test_fs_stat.js", "skip": ["nuttx"], "reason": "not implemented for nuttx" },
+    { "name": "test_fs_write.js", "skip": ["nuttx"], "reason": "not implemented for nuttx" },
     { "name": "test_fs_writefile.js" },
     { "name": "test_fs_writefile_sync.js" },
     { "name": "test_fs_writefile_unlink.js" },
@@ -56,7 +57,7 @@
     { "name": "test_net_8.js" },
     { "name": "test_net_9.js" },
     { "name": "test_net_10.js" },
-    { "name": "test_net_connect.js", "timeout": 10 },    
+    { "name": "test_net_connect.js", "timeout": 10 },
     { "name": "test_net_headers.js", "skip": ["nuttx"], "reason": "not implemented for nuttx" },
     { "name": "test_net_http_get.js", "timeout": 20, "skip": ["nuttx"], "reason": "not implemented for nuttx" },
     { "name": "test_net_http_response_twice.js", "timeout": 10, "skip": ["nuttx"], "reason": "not implemented for nuttx" },