Fix String roundtrip with interior nul bytes

crates/napi/src/bindgen_runtime/js_values/string.rs

@@ -2,7 +2,6 @@ use crate::{bindgen_prelude::*, check_status, sys, Error, Result, Status};
 
 use std::ffi::{c_void, CStr};
 use std::fmt::Display;
-#[cfg(feature = "latin1")]
 use std::mem;
 use std::ops::Deref;
 use std::ptr;
@@ -53,12 +52,15 @@ impl FromNapiValue for String {
       "Failed to convert napi `string` into rust type `String`"
     )?;
 
-    match unsafe { CStr::from_ptr(buf_ptr) }.to_str() {
+    let mut ret = mem::ManuallyDrop::new(ret);
+    let buf_ptr = ret.as_mut_ptr();
+    let bytes = unsafe { Vec::from_raw_parts(buf_ptr as *mut u8, written_char_count, len) };
+    match String::from_utf8(bytes) {
       Err(e) => Err(Error::new(
         Status::InvalidArg,
         format!("Failed to read utf8 string, {}", e),
       )),
-      Ok(s) => Ok(s.to_owned()),
+      Ok(s) => Ok(s),
     }
   }
 }

examples/napi/__test__/typegen.spec.ts.md

@@ -126,6 +126,7 @@ Generated by [AVA](https://avajs.dev).
     export function concatStr(s: string): string␊
     export function concatUtf16(s: string): string␊
     export function concatLatin1(s: string): string␊
+    export function roundtripStr(s: string): string␊
     export function setSymbolInObj(symbol: symbol): object␊
     export function createSymbol(): symbol␊
     export function withoutAbortController(a: number, b: number): Promise<number>␊

examples/napi/__test__/values.spec.ts

@@ -11,6 +11,7 @@ import {
   concatLatin1,
   concatStr,
   concatUtf16,
+  roundtripStr,
   getNums,
   getWords,
   sumNums,
@@ -106,6 +107,10 @@ test('string', (t) => {
     concatUtf16('JavaScript 🌳 你好 napi'),
     'JavaScript 🌳 你好 napi + Rust 🦀 string!',
   )
+  t.is(
+    roundtripStr('what up?!\u0000after the NULL'),
+    'what up?!\u0000after the NULL',
+  )
 })
 
 test('array', (t) => {

examples/napi/index.d.ts

@@ -116,6 +116,7 @@ export function contains(source: string, target: string): boolean
 export function concatStr(s: string): string
 export function concatUtf16(s: string): string
 export function concatLatin1(s: string): string
+export function roundtripStr(s: string): string
 export function setSymbolInObj(symbol: symbol): object
 export function createSymbol(): symbol
 export function withoutAbortController(a: number, b: number): Promise<number>

examples/napi/src/string.rs

@@ -20,3 +20,8 @@ fn concat_utf16(s: Utf16String) -> Utf16String {
 fn concat_latin1(s: Latin1String) -> String {
   format!("{} + Rust 🦀 string!", s)
 }
+
+#[napi]
+pub fn roundtrip_str(s: String) -> String {
+  s
+}