fix(napi-derive): catch_unwind on constructor (#1869)

- Close https://github.com/napi-rs/napi-rs/issues/1852

.github/workflows/zig.yaml

@@ -2,6 +2,7 @@ name: Zig-Cross-Compile
 
 env:
   DEBUG: 'napi:*'
+  TEST_ZIG_CROSS: '1'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -33,7 +34,7 @@ jobs:
       - name: Setup node
         uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: 'yarn'
       - name: Install
         uses: dtolnay/rust-toolchain@stable
@@ -99,7 +100,7 @@ jobs:
       - name: Setup node
         uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: 'yarn'
       - name: Install dependencies
         run: |

crates/backend/src/codegen/fn.rs

@@ -135,11 +135,16 @@ impl TryToTokens for NapiFn {
     {
       quote! { #native_call }
     } else if self.kind == FnKind::Constructor {
+      let return_from_factory = if self.catch_unwind {
+        quote! { return Ok(std::ptr::null_mut()); }
+      } else {
+        quote! { return std::ptr::null_mut(); }
+      };
       quote! {
         // constructor function is called from class `factory`
         // so we should skip the original `constructor` logic
         if napi::__private::___CALL_FROM_FACTORY.with(|inner| inner.load(std::sync::atomic::Ordering::Relaxed)) {
-          return std::ptr::null_mut();
+            #return_from_factory
         }
         #function_call_inner
       }

examples/napi/__tests__/__snapshots__/typegen.spec.ts.md

@@ -99,6 +99,14 @@ Generated by [AVA](https://avajs.dev).
     }␊
     export type Blake2bKey = Blake2BKey␊
     ␊
+    export class CatchOnConstructor {␊
+      constructor()␊
+    }␊
+    ␊
+    export class CatchOnConstructor2 {␊
+      constructor()␊
+    }␊
+    ␊
     export class ClassWithFactory {␊
       name: string␊
       static withName(name: string): ClassWithFactory␊

examples/napi/__tests__/values.spec.ts

@@ -108,6 +108,8 @@ const {
   arrayBufferPassThrough,
   JsRepo,
   CssStyleSheet,
+  CatchOnConstructor,
+  CatchOnConstructor2,
   asyncReduceBuffer,
   callbackReturnPromise,
   callbackReturnPromiseAndSpawn,
@@ -234,6 +236,24 @@ test('class', (t) => {
     // @ts-expect-error
     plusOne.call('')
   })
+
+  t.notThrows(() => {
+    new CatchOnConstructor()
+  })
+
+  if (!process.env.TEST_ZIG_CROSS) {
+    t.throws(
+      () => {
+        new CatchOnConstructor2()
+      },
+      (() =>
+        process.env.WASI_TEST
+          ? undefined
+          : {
+              message: 'CatchOnConstructor2 panic',
+            })(),
+    )
+  }
 })
 
 test('async self in class', async (t) => {

examples/napi/index.d.ts

@@ -89,6 +89,14 @@ export class Blake2BKey {
 }
 export type Blake2bKey = Blake2BKey
 
+export class CatchOnConstructor {
+  constructor()
+}
+
+export class CatchOnConstructor2 {
+  constructor()
+}
+
 export class ClassWithFactory {
   name: string
   static withName(name: string): ClassWithFactory

examples/napi/src/class.rs

@@ -432,3 +432,25 @@ impl GetterSetterWithClosures {
     Ok(Self {})
   }
 }
+
+#[napi]
+pub struct CatchOnConstructor {}
+
+#[napi]
+impl CatchOnConstructor {
+  #[napi(constructor, catch_unwind)]
+  pub fn new() -> Self {
+    Self {}
+  }
+}
+
+#[napi]
+pub struct CatchOnConstructor2 {}
+
+#[napi]
+impl CatchOnConstructor2 {
+  #[napi(constructor, catch_unwind)]
+  pub fn new() -> Self {
+    panic!("CatchOnConstructor2 panic");
+  }
+}