feat: impl FromNapiValue for serde_json::Number, fix it for Null, throw for impossible types (#1052)

fix #1013

Co-authored-by: zeroslope <jsx55242@foxmail.com>

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

@@ -1,4 +1,4 @@
-use serde_json::{Map, Value};
+use serde_json::{Map, Number, Value};
 
 use crate::{
   bindgen_runtime::Null, check_status, sys, type_of, Error, JsObject, Result, Status, ValueType,
@@ -11,20 +11,7 @@ impl ToNapiValue for Value {
     match val {
       Value::Null => unsafe { Null::to_napi_value(env, Null) },
       Value::Bool(b) => unsafe { bool::to_napi_value(env, b) },
-      Value::Number(n) => {
-        if n.is_i64() {
-          unsafe { i64::to_napi_value(env, n.as_i64().unwrap()) }
-        } else if n.is_f64() {
-          unsafe { f64::to_napi_value(env, n.as_f64().unwrap()) }
-        } else {
-          let n = n.as_u64().unwrap();
-          if n > u32::MAX as u64 {
-            todo!("impl BigInt")
-          } else {
-            unsafe { u32::to_napi_value(env, n as u32) }
-          }
-        }
-      }
+      Value::Number(n) => unsafe { Number::to_napi_value(env, n) },
       Value::String(s) => unsafe { String::to_napi_value(env, s) },
       Value::Array(arr) => unsafe { Vec::<Value>::to_napi_value(env, arr) },
       Value::Object(obj) => unsafe { Map::to_napi_value(env, obj) },
@@ -37,12 +24,7 @@ impl FromNapiValue for Value {
     let ty = type_of!(env, napi_val)?;
     let val = match ty {
       ValueType::Boolean => Value::Bool(unsafe { bool::from_napi_value(env, napi_val)? }),
-      ValueType::Number => {
-        return Err(Error::new(
-          Status::InvalidArg,
-          "Js Number is not be able to convert to rust.".to_owned(),
-        ));
-      }
+      ValueType::Number => Value::Number(unsafe { Number::from_napi_value(env, napi_val)? }),
       ValueType::String => Value::String(unsafe { String::from_napi_value(env, napi_val)? }),
       ValueType::Object => {
         let mut is_arr = false;
@@ -59,7 +41,37 @@ impl FromNapiValue for Value {
       }
       #[cfg(feature = "napi6")]
       ValueType::BigInt => todo!(),
-      _ => Value::Null,
+      ValueType::Null => Value::Null,
+      ValueType::Function => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "JS functions cannot be represented as a serde_json::Value".to_owned(),
+        ))
+      }
+      ValueType::Undefined => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "undefined cannot be represented as a serde_json::Value".to_owned(),
+        ))
+      }
+      ValueType::Symbol => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "JS symbols cannot be represented as a serde_json::Value".to_owned(),
+        ))
+      }
+      ValueType::External => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "External JS objects cannot be represented as a serde_json::Value".to_owned(),
+        ))
+      }
+      _ => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "Unknown JS variables cannot be represented as a serde_json::Value".to_owned(),
+        ))
+      }
     };
 
     Ok(val)
@@ -96,3 +108,50 @@ impl FromNapiValue for Map<String, Value> {
     Ok(map)
   }
 }
+
+impl ToNapiValue for Number {
+  unsafe fn to_napi_value(env: sys::napi_env, n: Self) -> Result<sys::napi_value> {
+    if n.is_i64() {
+      unsafe { i64::to_napi_value(env, n.as_i64().unwrap()) }
+    } else if n.is_f64() {
+      unsafe { f64::to_napi_value(env, n.as_f64().unwrap()) }
+    } else {
+      let n = n.as_u64().unwrap();
+      if n > u32::MAX as u64 {
+        todo!("impl BigInt")
+      } else {
+        unsafe { u32::to_napi_value(env, n as u32) }
+      }
+    }
+  }
+}
+
+impl FromNapiValue for Number {
+  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+    let n = unsafe { f64::from_napi_value(env, napi_val)? };
+    // Try to auto-convert to integers
+    let n = if n.trunc() == n {
+      if n >= 0.0f64 && n <= u32::MAX as f64 {
+        // This can be represented as u32
+        Some(Number::from(n as u32))
+      } else if n < 0.0f64 && n >= i32::MIN as f64 {
+        Some(Number::from(n as i32))
+      } else {
+        // must be a float
+        Number::from_f64(n)
+      }
+    } else {
+      // must be a float
+      Number::from_f64(n)
+    };
+
+    let n = n.ok_or_else(|| {
+      Error::new(
+        Status::InvalidArg,
+        "Failed to convert js number to serde_json::Number".to_owned(),
+      )
+    })?;
+
+    Ok(n)
+  }
+}

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

@@ -123,6 +123,7 @@ Generated by [AVA](https://avajs.dev).
     }␊
     export function readPackageJson(): PackageJson␊
     export function getPackageJsonName(packageJson: PackageJson): string␊
+    export function testSerdeRoundtrip(data: any): any␊
     export function contains(source: string, target: string): boolean␊
     export function concatStr(s: string): string␊
     export function concatUtf16(s: string): string␊

examples/napi/__test__/values.spec.ts

@@ -80,6 +80,7 @@ import {
   receiveMutClassOrNumber,
   getStrFromObject,
   returnJsFunction,
+  testSerdeRoundtrip,
 } from '../'
 
 test('export const', (t) => {
@@ -299,6 +300,34 @@ test('serde-json', (t) => {
   t.is(getPackageJsonName(packageJson), 'napi-rs')
 })
 
+test('serde-roundtrip', (t) => {
+  t.is(testSerdeRoundtrip(1), 1)
+  t.is(testSerdeRoundtrip(1.2), 1.2)
+  t.is(testSerdeRoundtrip(-1), -1)
+
+  t.deepEqual(testSerdeRoundtrip([1, 1.2, -1]), [1, 1.2, -1])
+  t.deepEqual(testSerdeRoundtrip({ a: 1, b: 1.2, c: -1 }), {
+    a: 1,
+    b: 1.2,
+    c: -1,
+  })
+  t.throws(() => testSerdeRoundtrip(NaN))
+
+  t.is(testSerdeRoundtrip(null), null)
+
+  let err = t.throws(() => testSerdeRoundtrip(undefined))
+  t.is(err!.message, 'undefined cannot be represented as a serde_json::Value')
+
+  err = t.throws(() => testSerdeRoundtrip(() => {}))
+  t.is(
+    err!.message,
+    'JS functions cannot be represented as a serde_json::Value',
+  )
+
+  err = t.throws(() => testSerdeRoundtrip(Symbol.for('foo')))
+  t.is(err!.message, 'JS symbols cannot be represented as a serde_json::Value')
+})
+
 test('buffer', (t) => {
   let buf = getBuffer()
   t.is(buf.toString('utf-8'), 'Hello world')

examples/napi/index.d.ts

@@ -113,6 +113,7 @@ export interface PackageJson {
 }
 export function readPackageJson(): PackageJson
 export function getPackageJsonName(packageJson: PackageJson): string
+export function testSerdeRoundtrip(data: any): any
 export function contains(source: string, target: string): boolean
 export function concatStr(s: string): string
 export function concatUtf16(s: string): string

examples/napi/src/serde.rs

@@ -25,3 +25,8 @@ fn read_package_json() -> Result<PackageJson> {
 fn get_package_json_name(package_json: PackageJson) -> String {
   package_json.name
 }
+
+#[napi]
+fn test_serde_roundtrip(data: Value) -> Value {
+  data
+}