add JsValue::is_array() + tests (#3087)

* add JsValue::is_array() + tests

* use Array.isArray() instead of instanceof

Author: mfreeborn

crates/cli-support/src/intrinsic.rs

@@ -95,6 +95,9 @@ intrinsics! {
         #[symbol = "__wbindgen_is_function"]
         #[signature = fn(ref_externref()) -> Boolean]
         IsFunction,
+        #[symbol = "__wbindgen_is_array"]
+        #[signature = fn(ref_externref()) -> Boolean]
+        IsArray,
         #[symbol = "__wbindgen_is_undefined"]
         #[signature = fn(ref_externref()) -> Boolean]
         IsUndefined,

crates/cli-support/src/js/mod.rs

@@ -3141,6 +3141,11 @@ impl<'a> Context<'a> {
                 format!("typeof({}) === 'function'", args[0])
             }
 
+            Intrinsic::IsArray => {
+                assert_eq!(args.len(), 1);
+                format!("Array.isArray({})", args[0])
+            }
+
             Intrinsic::IsUndefined => {
                 assert_eq!(args.len(), 1);
                 format!("{} === undefined", args[0])

src/lib.rs

@@ -348,6 +348,12 @@ impl JsValue {
         unsafe { __wbindgen_is_object(self.idx) == 1 }
     }
 
+    /// Tests whether this JS value is an instance of Array.
+    #[inline]
+    pub fn is_array(&self) -> bool {
+        unsafe { __wbindgen_is_array(self.idx) == 1 }
+    }
+
     /// Tests whether the type of this JS value is `function`.
     #[inline]
     pub fn is_function(&self) -> bool {
@@ -1003,6 +1009,7 @@ externs! {
         fn __wbindgen_is_undefined(idx: u32) -> u32;
         fn __wbindgen_is_symbol(idx: u32) -> u32;
         fn __wbindgen_is_object(idx: u32) -> u32;
+        fn __wbindgen_is_array(idx: u32) -> u32;
         fn __wbindgen_is_function(idx: u32) -> u32;
         fn __wbindgen_is_string(idx: u32) -> u32;
         fn __wbindgen_is_bigint(idx: u32) -> u32;

tests/wasm/intrinsics.rs

@@ -3,7 +3,7 @@
 use std::convert::TryFrom;
 use std::fmt::Debug;
 
-use js_sys::{Object, RangeError, Reflect};
+use js_sys::{Array, Object, RangeError, Reflect};
 use wasm_bindgen::{JsCast, JsValue};
 use wasm_bindgen_test::wasm_bindgen_test;
 
@@ -78,6 +78,7 @@ fn types() {
     assert!(JsValue::UNDEFINED.is_undefined());
     assert!(JsValue::NULL.is_null());
     assert!(Object::new().is_object());
+    assert!(Array::new().is_array());
     assert!(JsValue::symbol(None).is_symbol());
     assert!(JsValue::from_str("hi").is_string());
     assert!(JsValue::bigint_from_str("5").is_bigint());