fix(ext/node): cp into non-existent parent directory (#23469)

Fixes #20604

ext/fs/std_fs.rs

@@ -576,6 +576,12 @@ fn cp(from: &Path, to: &Path) -> FsResult<()> {
         );
       }
     }
+
+    // Ensure parent destination directory exists
+    if let Some(parent) = to.parent() {
+      fs::create_dir_all(parent)?;
+    }
+
     copy_file(from, to)
   }
 

tests/unit_node/_fs/_fs_copy_test.ts

@@ -2,7 +2,7 @@
 import * as path from "@std/path/mod.ts";
 import { assert } from "@std/assert/mod.ts";
 import { assertCallbackErrorUncaught } from "../_test_utils.ts";
-import { copyFile, copyFileSync, existsSync } from "node:fs";
+import { copyFile, copyFileSync, cpSync, existsSync } from "node:fs";
 
 const destFile = "./destination.txt";
 
@@ -50,3 +50,13 @@ Deno.test("[std/node/fs] copyFile callback isn't called twice if error is thrown
     },
   });
 });
+
+Deno.test("[std/node/fs] cp creates destination directory", async () => {
+  const tempDir = await Deno.makeTempDir();
+  const tempFile1 = path.join(tempDir, "file1.txt");
+  const tempFile2 = path.join(tempDir, "dir", "file2.txt");
+  await Deno.writeTextFile(tempFile1, "hello world");
+  cpSync(tempFile1, tempFile2);
+  assert(existsSync(tempFile2));
+  await Deno.remove(tempDir, { recursive: true });
+});