fix(ext/node): fix Buffer.copy when sourceStart > source.length (deno…

…land#21345)
crowlKats · Nov 28, 2023 · 567d7ff · 567d7ff
1 parent 4ed9278
commit 567d7ff
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Showing 4 changed files with 7 additions and 6 deletions.
diff --git a/cli/tests/node_compat/config.jsonc b/cli/tests/node_compat/config.jsonc
@@ -22,7 +22,6 @@
  "test-buffer-alloc.js",
  "test-buffer-arraybuffer.js",
  "test-buffer-bytelength.js",
- "test-buffer-copy.js",
  "test-buffer-from.js",
  "test-buffer-includes.js",
  "test-buffer-indexof.js",

diff --git a/cli/tests/node_compat/test/parallel/test-buffer-alloc.js b/cli/tests/node_compat/test/parallel/test-buffer-alloc.js
@@ -131,7 +131,7 @@ b.copy(Buffer.alloc(0), 1, 1, 1);
 b.copy(Buffer.alloc(1), 1, 1, 1);
 
 // Try to copy 0 bytes from past the end of the source buffer
-b.copy(Buffer.alloc(1), 0, 2048, 2048);
+b.copy(Buffer.alloc(1), 0, 1024, 1024);
 
 // Testing for smart defaults and ability to pass string values as offset
 {

diff --git a/cli/tests/node_compat/test/parallel/test-buffer-copy.js b/cli/tests/node_compat/test/parallel/test-buffer-copy.js
@@ -165,7 +165,6 @@ assert.throws(
  }
 );
 
-/*
 // Copy throws if sourceStart is greater than length of source
 assert.throws(
  () => Buffer.allocUnsafe(5).copy(Buffer.allocUnsafe(5), 0, 100),
@@ -174,7 +173,6 @@ assert.throws(
  name: 'RangeError',
  }
 );
-*/
 
 {
  // Check sourceEnd resets to targetEnd if former is greater than the latter

diff --git a/ext/node/polyfills/internal/buffer.mjs b/ext/node/polyfills/internal/buffer.mjs
@@ -1536,8 +1536,12 @@ Buffer.prototype.copy = function copy(
  sourceStart = 0;
  } else {
  sourceStart = toInteger(sourceStart, 0);
- if (sourceStart < 0) {
- throw new codes.ERR_OUT_OF_RANGE("sourceStart", ">= 0", sourceStart);
+ if (sourceStart < 0 || sourceStart > this.length) {
+ throw new codes.ERR_OUT_OF_RANGE(
+ "sourceStart",
+ `>= 0 && <= ${this.length}`,
+ sourceStart,
+ );
  }
  if (sourceStart >= MAX_UINT32) {
  throw new codes.ERR_OUT_OF_RANGE(