[ISSUE #2554 #2567] throw if fs args for 'start' or 'end' are strings

lib/fs.js

@@ -1038,8 +1038,13 @@ var ReadStream = fs.ReadStream = function(path, options) {
   if (this.encoding) this.setEncoding(this.encoding);
 
   if (this.start !== undefined) {
+    if ('number' !== typeof this.start) {
+      throw TypeError('start must be a Number');
+    }
     if (this.end === undefined) {
       this.end = Infinity;
+    } else if ('number' !== typeof this.end) {
+      throw TypeError('end must be a Number');
     }
 
     if (this.start > this.end) {
@@ -1226,6 +1231,9 @@ var WriteStream = fs.WriteStream = function(path, options) {
   }
 
   if (this.start !== undefined) {
+    if ('number' !== typeof this.start) {
+      throw TypeError('start must be a Number');
+    }
     if (this.start < 0) {
       throw new Error('start must be >= zero');
     }

test/simple/test-fs-non-number-arguments-throw.js

@@ -0,0 +1,24 @@
+var assert = require('assert'),
+    fs = require('fs'),
+    saneEmitter,
+    sanity = 'ire(\'assert\')';
+
+saneEmitter = fs.createReadStream(__filename, { start: 17, end: 29 });
+
+assert.throws(function () {
+  fs.createReadStream(__filename, { start: "17", end: 29 });
+}, "start as string didn't throw an error for createReadStream");
+
+assert.throws(function () {
+  fs.createReadStream(__filename, { start: 17, end: "29" });
+}, "end as string didn't throw an error");
+
+assert.throws(function () {
+  fs.createWriteStream(__filename, { start: "17" });
+}, "start as string didn't throw an error for createWriteStream");
+
+saneEmitter.on('data', function (data) {
+  // a sanity check when using numbers instead of strings
+  assert.strictEqual(sanity, data.toString('utf8'), 'read ' +
+                     data.toString('utf8') + ' instead of ' + sanity);
+});