feat(napi): implement either type

napi-derive/src/lib.rs

@@ -111,7 +111,7 @@ pub fn js_function(attr: TokenStream, input: TokenStream) -> TokenStream {
       }
 
       let mut env = Env::from_raw(raw_env);
-      let call_ctx = CallContext::new(&mut env, raw_this, &raw_args, #arg_len_span);
+      let call_ctx = CallContext::new(&mut env, raw_this, &raw_args, #arg_len_span, argc as usize);
       let result = call_ctx.and_then(|ctx| #new_fn_name(ctx));
       has_error = has_error && result.is_err();
 

napi/src/call_context.rs

@@ -1,10 +1,11 @@
-use crate::{sys, Env, Error, JsUnknown, NapiValue, Result, Status};
+use crate::{sys, Either, Env, Error, JsUndefined, JsUnknown, NapiValue, Result, Status};
 
 pub struct CallContext<'env, T: NapiValue = JsUnknown> {
   pub env: &'env Env,
   pub this: T,
   args: &'env [sys::napi_value],
   arg_len: usize,
+  actual_arg_length: usize,
 }
 
 impl<'env, T: NapiValue> CallContext<'env, T> {
@@ -14,12 +15,14 @@ impl<'env, T: NapiValue> CallContext<'env, T> {
     this: sys::napi_value,
     args: &'env [sys::napi_value],
     arg_len: usize,
+    actual_arg_length: usize,
   ) -> Result<Self> {
     Ok(Self {
       env,
       this: T::from_raw(env.0, this)?,
       args,
       arg_len,
+      actual_arg_length,
     })
   }
 
@@ -34,4 +37,20 @@ impl<'env, T: NapiValue> CallContext<'env, T> {
       ArgType::from_raw(self.env.0, self.args[index])
     }
   }
+
+  #[inline]
+  pub fn try_get<ArgType: NapiValue>(&self, index: usize) -> Result<Either<ArgType, JsUndefined>> {
+    if index + 1 > self.arg_len {
+      Err(Error {
+        status: Status::GenericFailure,
+        reason: "Arguments index out of range".to_owned(),
+      })
+    } else {
+      if index < self.actual_arg_length {
+        ArgType::from_raw(self.env.0, self.args[index]).map(Either::A)
+      } else {
+        self.env.get_undefined().map(Either::B)
+      }
+    }
+  }
 }

napi/src/env.rs

@@ -312,7 +312,7 @@ impl Env {
       check_status(status)?;
     };
 
-    Ok(T::from_raw_unchecked(self.0, raw_value))
+    T::from_raw(self.0, raw_value)
   }
 
   #[inline]
@@ -455,12 +455,7 @@ impl Env {
     let reason_string = self.create_string(reason.as_str())?;
     let mut result = ptr::null_mut();
     let status = unsafe {
-      sys::napi_create_error(
-        self.0,
-        ptr::null_mut(),
-        reason_string.into_raw(),
-        &mut result,
-      )
+      sys::napi_create_error(self.0, ptr::null_mut(), reason_string.0.value, &mut result)
     };
     check_status(status)?;
     Ok(JsObject::from_raw_unchecked(self.0, result))

napi/src/js_values/arraybuffer.rs

@@ -11,6 +11,20 @@ pub struct JsArrayBuffer {
   pub len: u64,
 }
 
+impl JsArrayBuffer {
+  pub(crate) fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
+    Self {
+      value: JsObject(Value {
+        env,
+        value,
+        value_type: ValueType::Object,
+      }),
+      data: ptr::null(),
+      len: 0,
+    }
+  }
+}
+
 impl NapiValue for JsArrayBuffer {
   fn raw_value(&self) -> sys::napi_value {
     self.value.0.value
@@ -31,16 +45,4 @@ impl NapiValue for JsArrayBuffer {
       len,
     })
   }
-
-  fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
-    Self {
-      value: JsObject(Value {
-        env,
-        value,
-        value_type: ValueType::Object,
-      }),
-      data: ptr::null(),
-      len: 0,
-    }
-  }
 }

napi/src/js_values/buffer.rs

@@ -14,6 +14,18 @@ pub struct JsBuffer {
 }
 
 impl JsBuffer {
+  pub(crate) fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
+    Self {
+      value: JsObject(Value {
+        env,
+        value,
+        value_type: ValueType::Object,
+      }),
+      data: ptr::null(),
+      len: 0,
+    }
+  }
+
   pub fn into_unknown(self) -> Result<JsUnknown> {
     self.value.into_unknown()
   }
@@ -39,18 +51,6 @@ impl NapiValue for JsBuffer {
       len,
     })
   }
-
-  fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
-    Self {
-      value: JsObject(Value {
-        env,
-        value,
-        value_type: ValueType::Object,
-      }),
-      data: ptr::null(),
-      len: 0,
-    }
-  }
 }
 
 impl AsRef<[u8]> for JsBuffer {

napi/src/js_values/class_property.rs

@@ -41,7 +41,7 @@ impl Property {
   }
 
   pub(crate) fn into_raw(mut self, env: &Env) -> Result<sys::napi_property_descriptor> {
-    self.raw_descriptor.name = env.create_string(&self.name)?.into_raw();
+    self.raw_descriptor.name = env.create_string(&self.name)?.raw_value();
     Ok(self.raw_descriptor)
   }
 }

napi/src/js_values/either.rs

@@ -0,0 +1,31 @@
+use crate::{sys, JsUndefined, NapiValue, Result};
+
+#[derive(Debug, Clone, Copy)]
+pub enum Either<A: NapiValue, B: NapiValue> {
+  A(A),
+  B(B),
+}
+
+impl<T: NapiValue> Into<Option<T>> for Either<T, JsUndefined> {
+  fn into(self) -> Option<T> {
+    match self {
+      Either::A(v) => Some(v),
+      Either::B(_) => None,
+    }
+  }
+}
+
+impl<A: NapiValue, B: NapiValue> NapiValue for Either<A, B> {
+  fn from_raw(env: sys::napi_env, value: sys::napi_value) -> Result<Either<A, B>> {
+    A::from_raw(env, value)
+      .map(Self::A)
+      .or_else(|_| B::from_raw(env, value).map(Self::B))
+  }
+
+  fn raw_value(&self) -> sys::napi_value {
+    match self {
+      Either::A(v) => v.raw_value(),
+      Either::B(v) => v.raw_value(),
+    }
+  }
+}

napi/src/js_values/function.rs

@@ -26,12 +26,12 @@ impl JsFunction {
   /// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
   pub fn call(&self, this: Option<&JsObject>, args: &[JsUnknown]) -> Result<JsUnknown> {
     let raw_this = this
-      .map(|v| v.into_raw())
+      .map(|v| v.raw_value())
       .or_else(|| {
         Env::from_raw(self.0.env)
           .get_undefined()
           .ok()
-          .map(|u| u.into_raw())
+          .map(|u| u.raw_value())
       })
       .ok_or(Error::new(
         Status::Unknown,

napi/src/js_values/mod.rs

@@ -8,11 +8,13 @@ mod arraybuffer;
 mod boolean;
 mod buffer;
 mod class_property;
+mod either;
 mod function;
 mod number;
 mod object;
 mod string;
 mod tagged_object;
+mod undefined;
 mod value;
 mod value_ref;
 mod value_type;
@@ -21,11 +23,13 @@ pub use arraybuffer::JsArrayBuffer;
 pub use boolean::JsBoolean;
 pub use buffer::JsBuffer;
 pub use class_property::Property;
+pub use either::Either;
 pub use function::JsFunction;
 pub use number::JsNumber;
 pub use object::JsObject;
 pub use string::JsString;
 pub(crate) use tagged_object::TaggedObject;
+pub use undefined::JsUndefined;
 pub(crate) use value::Value;
 pub(crate) use value_ref::Ref;
 pub use value_type::ValueType;
@@ -34,9 +38,6 @@ pub use value_type::ValueType;
 #[derive(Clone, Copy, Debug)]
 pub struct JsUnknown(pub(crate) Value);
 
-#[derive(Clone, Copy, Debug)]
-pub struct JsUndefined(pub(crate) Value);
-
 #[derive(Clone, Copy, Debug)]
 pub struct JsNull(pub(crate) Value);
 
@@ -78,17 +79,20 @@ macro_rules! impl_napi_value_trait {
         }
       }
 
-      fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
+      fn raw_value(&self) -> sys::napi_value {
+        self.0.value
+      }
+    }
+
+    impl $js_value {
+      #[inline]
+      pub fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
         Self(Value {
           env,
           value,
           value_type: $value_type,
         })
       }
-
-      fn raw_value(&self) -> sys::napi_value {
-        self.0.value
-      }
     }
   };
 }
@@ -96,12 +100,12 @@ macro_rules! impl_napi_value_trait {
 macro_rules! impl_js_value_methods {
   ($js_value:ident) => {
     impl $js_value {
-      pub fn into_raw(self) -> sys::napi_value {
-        self.0.value
-      }
+      #[inline]
       pub fn into_unknown(self) -> Result<JsUnknown> {
         JsUnknown::from_raw(self.0.env, self.0.value)
       }
+
+      #[inline]
       pub fn coerce_to_number(self) -> Result<JsNumber> {
         let mut new_raw_value = ptr::null_mut();
         let status =
@@ -113,6 +117,7 @@ macro_rules! impl_js_value_methods {
           value_type: ValueType::Number,
         }))
       }
+      #[inline]
       pub fn coerce_to_string(self) -> Result<JsString> {
         let mut new_raw_value = ptr::null_mut();
         let status =
@@ -152,8 +157,6 @@ macro_rules! impl_js_value_methods {
 pub trait NapiValue: Sized {
   fn from_raw(env: sys::napi_env, value: sys::napi_value) -> Result<Self>;
 
-  fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self;
-
   fn raw_value(&self) -> sys::napi_value;
 }
 
@@ -186,15 +189,11 @@ impl_napi_value_trait!(JsSymbol, Symbol);
 
 impl NapiValue for JsUnknown {
   fn from_raw(env: sys::napi_env, value: sys::napi_value) -> Result<Self> {
-    Ok(Self::from_raw_unchecked(env, value))
-  }
-
-  fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> JsUnknown {
-    JsUnknown(Value {
+    Ok(JsUnknown(Value {
       env,
       value,
       value_type: Unknown,
-    })
+    }))
   }
 
   fn raw_value(&self) -> sys::napi_value {

napi/src/js_values/string.rs

@@ -7,7 +7,7 @@ use std::str;
 
 use super::Value;
 use crate::error::check_status;
-use crate::{sys, Error, JsNumber, NapiValue, Result, Status};
+use crate::{sys, Error, JsNumber, Result, Status};
 
 #[derive(Clone, Copy, Debug)]
 pub struct JsString(pub(crate) Value);

napi/src/js_values/undefined.rs

@@ -0,0 +1,4 @@
+use super::Value;
+
+#[derive(Clone, Copy, Debug)]
+pub struct JsUndefined(pub(crate) Value);

napi/src/lib.rs

@@ -159,7 +159,7 @@ macro_rules! register_module {
           let hook_result = Ok(());
 
           match hook_result.and_then(move |_| result) {
-            Ok(_) => exports.into_raw(),
+            Ok(_) => exports.raw_value(),
             Err(e) => {
               unsafe {
                 sys::napi_throw_error(

napi/src/threadsafe_function.rs

@@ -207,9 +207,9 @@ unsafe extern "C" fn call_js_cb<T: ToJs>(
     let values = ret.unwrap();
     let js_null = env.get_null().unwrap();
     let mut raw_values: Vec<sys::napi_value> = vec![];
-    raw_values.push(js_null.into_raw());
+    raw_values.push(js_null.0.value);
     for item in values.iter() {
-      raw_values.push(item.into_raw())
+      raw_values.push(item.0.value)
     }
 
     status = sys::napi_call_function(

test_module/__test__/either.spec.js

@@ -0,0 +1,14 @@
+const test = require('ava')
+
+const bindings = require('../index.node')
+
+test('either should work', (t) => {
+  const fixture = 'napi'
+  t.is(bindings.eitherNumberString(1), 101)
+  t.is(bindings.eitherNumberString(fixture), `Either::B(${fixture})`)
+})
+
+test('dynamic argument length should work', (t) => {
+  t.is(bindings.dynamicArgumentLength(1), 101)
+  t.is(bindings.dynamicArgumentLength(), 42)
+})

test_module/src/either.rs

@@ -0,0 +1,29 @@
+use std::convert::TryInto;
+
+use napi::{CallContext, Either, JsNumber, JsString, Result};
+
+#[js_function(1)]
+pub fn either_number_string(ctx: CallContext) -> Result<Either<JsNumber, JsString>> {
+  let arg = ctx.get::<Either<JsNumber, JsString>>(0)?;
+  match arg {
+    Either::A(n) => {
+      let n: u32 = n.try_into()?;
+      ctx.env.create_uint32(n + 100).map(Either::A)
+    }
+    Either::B(s) => {
+      let content = format!("Either::B({})", s.as_str()?);
+      ctx.env.create_string_from_std(content).map(Either::B)
+    }
+  }
+}
+
+#[js_function(1)]
+pub fn dynamic_argument_length(ctx: CallContext) -> Result<JsNumber> {
+  let value: Option<JsNumber> = ctx.try_get::<JsNumber>(0)?.into();
+  if let Some(n) = value {
+    let n: u32 = n.try_into()?;
+    ctx.env.create_uint32(n + 100)
+  } else {
+    ctx.env.create_uint32(42)
+  }
+}

test_module/src/lib.rs

@@ -15,6 +15,7 @@ mod napi5;
 mod tokio_rt;
 
 mod buffer;
+mod either;
 mod external;
 mod function;
 mod napi_version;
@@ -22,6 +23,7 @@ mod symbol;
 mod task;
 
 use buffer::{buffer_to_string, get_buffer_length};
+use either::{dynamic_argument_length, either_number_string};
 use external::{create_external, get_external_count};
 use function::{call_function, call_function_with_this};
 #[cfg(napi4)]
@@ -52,6 +54,8 @@ fn init(module: &mut Module) -> Result<()> {
   module.create_named_method("getNapiVersion", get_napi_version)?;
   module.create_named_method("testCallFunction", call_function)?;
   module.create_named_method("testCallFunctionWithThis", call_function_with_this)?;
+  module.create_named_method("eitherNumberString", either_number_string)?;
+  module.create_named_method("dynamicArgumentLength", dynamic_argument_length)?;
   #[cfg(napi4)]
   module.create_named_method("testExecuteTokioReadfile", test_execute_tokio_readfile)?;
   #[cfg(napi4)]