Expose primitive information about JsObject

Adds bindings for wbindgen to fill in via JS bindings to read the various
primitive properties of a JS value.

crates/wasm-bindgen-cli-support/src/ts.rs

@@ -525,58 +525,151 @@ impl Js {
             extra_imports_interface.push_str("}\n");
         }
 
-        if self.wasm_import_needed("__wbindgen_object_clone_ref", m) {
-            self.expose_add_heap_object();
-            self.expose_get_object();
-            let bump_cnt = if self.debug {
-                String::from("
-                    if (typeof(val) === 'number')
-                        throw new Error('corrupt slab');
-                    val.cnt += 1;
-                ")
-            } else {
-                String::from("(val as {cnt:number}).cnt += 1;")
+        {
+            let mut bind = |name: &str, f: &Fn(&mut Self) -> String| {
+                if !self.wasm_import_needed(name, m) {
+                    return
+                }
+                imports_object.push_str(&format!("
+                    {}: {},
+                ", m.import_name(name), f(self)));
             };
-            imports_object.push_str(&format!("
-                {}: function(idx: number): number {{
-                    // If this object is on the stack promote it to the heap.
-                    if ((idx & 1) === 1)
-                        return addHeapObject(getObject(idx));
 
-                    // Otherwise if the object is on the heap just bump the
-                    // refcount and move on
-                    const val = slab[idx >> 1];
-                    {}
-                    return idx;
-                }},
-            ", m.import_name("__wbindgen_object_clone_ref"), bump_cnt));
-        }
+            bind("__wbindgen_object_clone_ref", &|me| {
+                me.expose_add_heap_object();
+                me.expose_get_object();
+                let bump_cnt = if me.debug {
+                    String::from("
+                        if (typeof(val) === 'number')
+                            throw new Error('corrupt slab');
+                        val.cnt += 1;
+                    ")
+                } else {
+                    String::from("(val as {cnt:number}).cnt += 1;")
+                };
+                format!("
+                    function(idx: number): number {{
+                        // If this object is on the stack promote it to the heap.
+                        if ((idx & 1) === 1)
+                            return addHeapObject(getObject(idx));
 
-        if self.wasm_import_needed("__wbindgen_object_drop_ref", m) {
-            self.expose_drop_ref();
-            let name = m.import_name("__wbindgen_object_drop_ref");
-            imports_object.push_str(&format!("{}: dropRef,\n", name));
-        }
+                        // Otherwise if the object is on the heap just bump the
+                        // refcount and move on
+                        const val = slab[idx >> 1];
+                        {}
+                        return idx;
+                    }}
+                ", bump_cnt)
+            });
 
-        if self.wasm_import_needed("__wbindgen_string_new", m) {
-            self.expose_add_heap_object();
-            self.expose_get_string_from_wasm();
-            imports_object.push_str(&format!("
-                {}: function(ptr: number, len: number): number {{
-                    return addHeapObject(getStringFromWasm(ptr, len));
-                }},
-            ", m.import_name("__wbindgen_string_new")));
-        }
+            bind("__wbindgen_object_drop_ref", &|me| {
+                me.expose_drop_ref();
+                "dropRef".to_string()
+            });
 
-        if self.wasm_import_needed("__wbindgen_throw", m) {
-            self.expose_get_string_from_wasm();
-            imports_object.push_str(&format!("\
-                {}: function(ptr: number, len: number) {{
-                    throw new Error(getStringFromWasm(ptr, len));
-                }},
-            ",
-                m.import_name("__wbindgen_throw"),
-            ));
+            bind("__wbindgen_string_new", &|me| {
+                me.expose_add_heap_object();
+                me.expose_get_string_from_wasm();
+                String::from("(p, l) => addHeapObject(getStringFromWasm(p, l))")
+            });
+
+            bind("__wbindgen_number_new", &|me| {
+                me.expose_add_heap_object();
+                String::from("addHeapObject")
+            });
+
+            bind("__wbindgen_number_get", &|me| {
+                me.expose_global_memory();
+                String::from("
+                    function(n: number, invalid: number): number {
+                        let obj = getObject(n);
+                        if (typeof(obj) === 'number')
+                            return obj;
+                        (new Uint8Array(memory.buffer))[invalid] = 1;
+                        return 0;
+                    }
+                ")
+            });
+
+            bind("__wbindgen_undefined_new", &|me| {
+                me.expose_add_heap_object();
+                String::from("() => addHeapObject(undefined)")
+            });
+
+            bind("__wbindgen_null_new", &|me| {
+                me.expose_add_heap_object();
+                String::from("() => addHeapObject(null)")
+            });
+
+            bind("__wbindgen_is_null", &|me| {
+                me.expose_get_object();
+                String::from("(idx) => getObject(idx) === null ? 1 : 0")
+            });
+
+            bind("__wbindgen_is_undefined", &|me| {
+                me.expose_get_object();
+                String::from("(idx) => getObject(idx) === undefined ? 1 : 0")
+            });
+
+            bind("__wbindgen_boolean_new", &|me| {
+                me.expose_add_heap_object();
+                String::from("(v) => addHeapObject(v == 1)")
+            });
+
+            bind("__wbindgen_boolean_get", &|me| {
+                me.expose_get_object();
+                String::from("(i) => {
+                    let v = getObject(i);
+                    if (typeof(v) == 'boolean') {
+                        return v ? 1 : 0;
+                    } else {
+                        return 2;
+                    }
+                }")
+            });
+
+            bind("__wbindgen_symbol_new", &|me| {
+                me.expose_get_string_from_wasm();
+                me.expose_add_heap_object();
+                String::from("(ptr, len) => {
+                    let a: Symbol;
+                    console.log(ptr, len);
+                    if (ptr === 0) {
+                        a = Symbol();
+                    } else {
+                        a = Symbol(getStringFromWasm(ptr, len));
+                    }
+                    return addHeapObject(a);
+                }")
+            });
+
+            bind("__wbindgen_is_symbol", &|me| {
+                me.expose_get_object();
+                String::from("(i) => typeof(getObject(i)) == 'symbol' ? 1 : 0")
+            });
+
+            bind("__wbindgen_throw", &|me| {
+                me.expose_get_string_from_wasm();
+                String::from("
+                    function(ptr: number, len: number) {
+                        throw new Error(getStringFromWasm(ptr, len));
+                    }
+                ")
+            });
+
+            bind("__wbindgen_string_get", &|me| {
+                me.expose_pass_string_to_wasm(m);
+                me.expose_get_object();
+                me.expose_global_memory();
+                String::from("(i, len_ptr) => {
+                    let obj = getObject(i);
+                    if (typeof(obj) !== 'string')
+                        return 0;
+                    const [ptr, len] = passStringToWasm(obj);
+                    (new Uint32Array(memory.buffer))[len_ptr / 4] = len;
+                    return ptr;
+                }")
+            });
         }
 
         let mut writes = String::new();

src/lib.rs

@@ -9,6 +9,7 @@
 extern crate wasm_bindgen_macro;
 
 use std::mem;
+use std::ptr;
 
 /// A module which is typically glob imported from:
 ///
@@ -31,7 +32,7 @@ pub struct JsObject {
 }
 
 impl JsObject {
-    /// Creates a new JS object which is a string.
+    /// Creates a new JS value which is a string.
     ///
     /// The utf-8 string provided is copied to the JS heap and the string will
     /// be owned by the JS garbage collector.
@@ -41,6 +42,52 @@ impl JsObject {
         }
     }
 
+    /// Creates a new JS value which is a number.
+    ///
+    /// This function creates a JS value representing a number (a heap
+    /// allocated number) and returns a handle to the JS version of it.
+    pub fn from_f64(n: f64) -> JsObject {
+        unsafe {
+            JsObject::__from_idx(__wbindgen_number_new(n))
+        }
+    }
+
+    /// Creates a new JS value which is a boolean.
+    ///
+    /// This function creates a JS object representing a boolean (a heap
+    /// allocated boolean) and returns a handle to the JS version of it.
+    pub fn from_bool(b: bool) -> JsObject {
+        unsafe {
+            JsObject::__from_idx(__wbindgen_boolean_new(b as u32))
+        }
+    }
+
+    /// Creates a new JS value representing `undefined`.
+    pub fn undefined() -> JsObject {
+        unsafe {
+            JsObject::__from_idx(__wbindgen_undefined_new())
+        }
+    }
+
+    /// Creates a new JS value representing `null`.
+    pub fn null() -> JsObject {
+        unsafe {
+            JsObject::__from_idx(__wbindgen_null_new())
+        }
+    }
+
+    /// Creates a new JS symbol with the optional description specified.
+    ///
+    /// This function will invoke the `Symbol` constructor in JS and return the
+    /// JS object corresponding to the symbol created.
+    pub fn symbol(description: Option<&str>) -> JsObject {
+        unsafe {
+            let ptr = description.map(|s| s.as_ptr()).unwrap_or(ptr::null());
+            let len = description.map(|s| s.len()).unwrap_or(0);
+            JsObject::__from_idx(__wbindgen_symbol_new(ptr, len))
+        }
+    }
+
     #[doc(hidden)]
     pub fn __from_idx(idx: u32) -> JsObject {
         JsObject { idx }
@@ -57,6 +104,77 @@ impl JsObject {
         mem::forget(self);
         return ret
     }
+
+    /// Returns the `f64` value of this JS value if it's an instance of a
+    /// number.
+    ///
+    /// If this JS value is not an instance of a number then this returns
+    /// `None`.
+    pub fn as_f64(&self) -> Option<f64> {
+        let mut invalid = 0;
+        unsafe {
+            let ret = __wbindgen_number_get(self.idx, &mut invalid);
+            if invalid == 1 {
+                None
+            } else {
+                Some(ret)
+            }
+        }
+    }
+
+    /// Returns the `String` of this JS value if it's an instance of a
+    /// string and it's valid utf-8.
+    ///
+    /// If this JS value is not an instance of a string or if it's not valid
+    /// utf-8 then this returns `None`.
+    pub fn as_string(&self) -> Option<String> {
+        unsafe {
+            let mut len = 0;
+            let ptr = __wbindgen_string_get(self.idx, &mut len);
+            if ptr.is_null() {
+                None
+            } else {
+                let data = Vec::from_raw_parts(ptr, len, len);
+                Some(String::from_utf8_unchecked(data))
+            }
+        }
+    }
+
+    /// Returns the `bool` value of this JS value if it's an instance of a
+    /// boolean.
+    ///
+    /// If this JS value is not an instance of a boolean then this returns
+    /// `None`.
+    pub fn as_bool(&self) -> Option<bool> {
+        unsafe {
+            match __wbindgen_boolean_get(self.idx) {
+                0 => Some(false),
+                1 => Some(true),
+                _ => None,
+            }
+        }
+    }
+
+    /// Tests whether this JS value is `null`
+    pub fn is_null(&self) -> bool {
+        unsafe {
+            __wbindgen_is_null(self.idx) == 1
+        }
+    }
+
+    /// Tests whether this JS value is `undefined`
+    pub fn is_undefined(&self) -> bool {
+        unsafe {
+            __wbindgen_is_undefined(self.idx) == 1
+        }
+    }
+
+    /// Tests whether the type of this JS value is `symbol`
+    pub fn is_symbol(&self) -> bool {
+        unsafe {
+            __wbindgen_is_symbol(self.idx) == 1
+        }
+    }
 }
 
 impl<'a> From<&'a str> for JsObject {
@@ -65,10 +183,45 @@ impl<'a> From<&'a str> for JsObject {
     }
 }
 
+impl<'a> From<&'a String> for JsObject {
+    fn from(s: &'a String) -> JsObject {
+        JsObject::from_str(s)
+    }
+}
+
+impl From<bool> for JsObject {
+    fn from(s: bool) -> JsObject {
+        JsObject::from_bool(s)
+    }
+}
+
+macro_rules! numbers {
+    ($($n:ident)*) => ($(
+        impl From<$n> for JsObject {
+            fn from(n: $n) -> JsObject {
+                JsObject::from_f64(n.into())
+            }
+        }
+    )*)
+}
+
+numbers! { i8 u8 i16 u16 i32 u32 f32 f64 }
+
 extern {
     fn __wbindgen_object_clone_ref(idx: u32) -> u32;
     fn __wbindgen_object_drop_ref(idx: u32);
     fn __wbindgen_string_new(ptr: *const u8, len: usize) -> u32;
+    fn __wbindgen_number_new(f: f64) -> u32;
+    fn __wbindgen_number_get(idx: u32, invalid: *mut u8) -> f64;
+    fn __wbindgen_null_new() -> u32;
+    fn __wbindgen_undefined_new() -> u32;
+    fn __wbindgen_is_null(idx: u32) -> u32;
+    fn __wbindgen_is_undefined(idx: u32) -> u32;
+    fn __wbindgen_boolean_new(val: u32) -> u32;
+    fn __wbindgen_boolean_get(idx: u32) -> u32;
+    fn __wbindgen_symbol_new(ptr: *const u8, len: usize) -> u32;
+    fn __wbindgen_is_symbol(idx: u32) -> u32;
+    fn __wbindgen_string_get(idx: u32, len: *mut usize) -> *mut u8;
 }
 
 impl Clone for JsObject {

tests/api.rs

@@ -18,6 +18,82 @@ fn works() {
                 pub fn bar(s: &str) -> JsObject {
                     JsObject::from(s)
                 }
+
+                pub fn baz() -> JsObject {
+                    JsObject::from(1.0)
+                }
+
+                pub fn baz2(a: &JsObject, b: &JsObject) {
+                    assert_eq!(a.as_f64(), Some(2.0));
+                    assert_eq!(b.as_f64(), None);
+                }
+
+                pub fn js_null() -> JsObject {
+                    JsObject::null()
+                }
+
+                pub fn js_undefined() -> JsObject {
+                    JsObject::undefined()
+                }
+
+                pub fn test_is_null_undefined(
+                    a: &JsObject,
+                    b: &JsObject,
+                    c: &JsObject,
+                ) {
+                    assert!(a.is_null());
+                    assert!(!a.is_undefined());
+
+                    assert!(!b.is_null());
+                    assert!(b.is_undefined());
+
+                    assert!(!c.is_null());
+                    assert!(!c.is_undefined());
+                }
+
+                pub fn get_true() -> JsObject {
+                    JsObject::from(true)
+                }
+
+                pub fn get_false() -> JsObject {
+                    JsObject::from(false)
+                }
+
+                pub fn test_bool(
+                    a: &JsObject,
+                    b: &JsObject,
+                    c: &JsObject,
+                ) {
+                    assert_eq!(a.as_bool(), Some(true));
+                    assert_eq!(b.as_bool(), Some(false));
+                    assert_eq!(c.as_bool(), None);
+                }
+
+                pub fn mk_symbol() -> JsObject {
+                    let a = JsObject::symbol(None);
+                    assert!(a.is_symbol());
+                    return a
+                }
+
+                pub fn mk_symbol2(s: &str) -> JsObject {
+                    let a = JsObject::symbol(Some(s));
+                    assert!(a.is_symbol());
+                    return a
+                }
+
+                pub fn assert_symbols(a: &JsObject, b: &JsObject) {
+                    assert!(a.is_symbol());
+                    assert!(!b.is_symbol());
+                }
+
+                pub fn acquire_string(a: &JsObject, b: &JsObject) {
+                    assert_eq!(a.as_string().unwrap(), "foo");
+                    assert_eq!(b.as_string(), None);
+                }
+
+                pub fn acquire_string2(a: &JsObject) -> String {
+                    a.as_string().unwrap_or("wrong".to_string())
+                }
             }
         "#)
         .file("test.ts", r#"
@@ -29,6 +105,27 @@ fn works() {
             export function test(wasm: Exports) {
                 assert.strictEqual(wasm.foo(), 'foo');
                 assert.strictEqual(wasm.bar('a'), 'a');
+                assert.strictEqual(wasm.baz(), 1);
+                wasm.baz2(2, 'a');
+
+                assert.strictEqual(wasm.js_null(), null);
+                assert.strictEqual(wasm.js_undefined(), undefined);
+
+                wasm.test_is_null_undefined(null, undefined, 1.0);
+
+                assert.strictEqual(wasm.get_true(), true);
+                assert.strictEqual(wasm.get_false(), false);
+                wasm.test_bool(true, false, 1.0);
+
+                assert.strictEqual(typeof(wasm.mk_symbol()), 'symbol');
+                assert.strictEqual(typeof(wasm.mk_symbol2('a')), 'symbol');
+                assert.strictEqual(Symbol.keyFor(wasm.mk_symbol()), undefined);
+                assert.strictEqual(Symbol.keyFor(wasm.mk_symbol2('b')), undefined);
+
+                wasm.assert_symbols(Symbol(), 'a');
+                wasm.acquire_string('foo', null)
+                assert.strictEqual(wasm.acquire_string2(''), '');
+                assert.strictEqual(wasm.acquire_string2('a'), 'a');
             }
         "#)
         .test();