From ca7adcafda9151733827a47b845fdbe32f91ca19 Mon Sep 17 00:00:00 2001
From: ZYSzys <17367077526@163.com>
Date: Sat, 29 Dec 2018 16:30:19 +0800
Subject: [PATCH] fs: extract start and end check into checkPosition

PR-URL: https://github.com/nodejs/node/pull/25264
Reviewed-By: Weijia Wang <starkwang@126.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
---
 lib/internal/fs/streams.js | 43 +++++++++++++-------------------------
 1 file changed, 15 insertions(+), 28 deletions(-)

diff --git a/lib/internal/fs/streams.js b/lib/internal/fs/streams.js
index c311fb59c825da..224752b1011c24 100644
--- a/lib/internal/fs/streams.js
+++ b/lib/internal/fs/streams.js
@@ -37,6 +37,19 @@ function allocNewPool(poolSize) {
   pool.used = 0;
 }
 
+// Check the `this.start` and `this.end` of stream.
+function checkPosition(pos, name) {
+  if (!Number.isSafeInteger(pos)) {
+    validateNumber(pos, name);
+    if (!Number.isInteger(pos))
+      throw new ERR_OUT_OF_RANGE(name, 'an integer', pos);
+    throw new ERR_OUT_OF_RANGE(name, '>= 0 and <= 2 ** 53 - 1', pos);
+  }
+  if (pos < 0) {
+    throw new ERR_OUT_OF_RANGE(name, '>= 0 and <= 2 ** 53 - 1', pos);
+  }
+}
+
 function ReadStream(path, options) {
   if (!(this instanceof ReadStream))
     return new ReadStream(path, options);
@@ -65,23 +78,7 @@ function ReadStream(path, options) {
   this.closed = false;
 
   if (this.start !== undefined) {
-    if (!Number.isSafeInteger(this.start)) {
-      validateNumber(this.start, 'start');
-      if (!Number.isInteger(this.start))
-        throw new ERR_OUT_OF_RANGE('start', 'an integer', this.start);
-      throw new ERR_OUT_OF_RANGE(
-        'start',
-        '>= 0 and <= 2 ** 53 - 1',
-        this.start
-      );
-    }
-    if (this.start < 0) {
-      throw new ERR_OUT_OF_RANGE(
-        'start',
-        '>= 0 and <= 2 ** 53 - 1',
-        this.start
-      );
-    }
+    checkPosition(this.start, 'start');
 
     this.pos = this.start;
   }
@@ -89,17 +86,7 @@ function ReadStream(path, options) {
   if (this.end === undefined) {
     this.end = Infinity;
   } else if (this.end !== Infinity) {
-    if (!Number.isSafeInteger(this.end)) {
-      if (typeof this.end !== 'number')
-        throw new ERR_INVALID_ARG_TYPE('end', 'number', this.end);
-      if (!Number.isInteger(this.end))
-        throw new ERR_OUT_OF_RANGE('end', 'an integer', this.end);
-      throw new ERR_OUT_OF_RANGE('end', '>= 0 and <= 2 ** 53 - 1', this.end);
-    }
-
-    if (this.end < 0) {
-      throw new ERR_OUT_OF_RANGE('end', '>= 0 and <= 2 ** 53 - 1', this.end);
-    }
+    checkPosition(this.end, 'end');
 
     if (this.start !== undefined && this.start > this.end) {
       throw new ERR_OUT_OF_RANGE(