feat: update bind and call

seognil · Mar 12, 2021 · ada5c5e · ada5c5e
1 parent a9462e6
commit ada5c5e
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Showing 2 changed files with 33 additions and 22 deletions.
diff --git a/js/reimplement/bind.ts b/js/reimplement/bind.ts
@@ -3,48 +3,60 @@
 {
   const obj = {
     val: 'inner',
-    fn(...args: any[]) {
+    fn(...args: unknown[]) {
       console.warn(...args, this);
     },
   };
 
-  obj.fn(333);
+  obj.fn('obj call');
 
   const rawFn = obj.fn;
-  rawFn(666);
+  rawFn('raw call');
 
   const bindedFn = obj.fn.bind({ val: 'outer' });
-  bindedFn(999);
+  bindedFn('bind1');
 
   const bindedFn2 = bindedFn.bind({ val: 'more' });
-  bindedFn2(0);
+  bindedFn2('bind2');
 }
 
 console.log('--------');
 
 // * ================================================================================ our
 
 {
-  const bind = <T, K>(context: any, fn: (...args: T[]) => K) => (...args: T[]) =>
-    fn.apply(context, args);
+  const bind = <C, T, K>(context: C, fn: (...args: T[]) => K) => {
+    const sf = Symbol();
+
+    Object.defineProperty(context, sf, {
+      enumerable: false,
+      configurable: true,
+      writable: true,
+      value: fn,
+    });
+
+    const sc: C & { [sf]?: Function } = context;
+
+    return (...args: T[]) => sc[sf]?.(...args) as K;
+  };
 
   // * ----------------
 
   const obj = {
     val: 'inner',
-    fn(...args: any[]) {
+    fn(...args: unknown[]) {
       console.warn(...args, this);
     },
   };
 
-  obj.fn(333);
+  obj.fn('obj call');
 
   const rawFn = obj.fn;
-  rawFn(666);
+  rawFn('raw call');
 
   const bindedFn = bind({ val: 'outer' }, obj.fn);
-  bindedFn(999);
+  bindedFn('bind1');
 
   const bindedFn2 = bind({ val: 'more' }, bindedFn);
-  bindedFn2(0);
+  bindedFn2('bind2');
 }
diff --git a/js/reimplement/call.ts b/js/reimplement/call.ts
@@ -3,7 +3,7 @@
 {
   const obj = {
     val: 'inner',
-    fn(...args: any[]) {
+    fn(...args: unknown[]) {
       console.warn(...args, this);
     },
   };
@@ -17,20 +17,19 @@ console.log('--------');
 // * ================================================================================ our
 
 {
-  const call = <T>(context: any, fn: Function, ...args: T[]) => {
-    let i = 0;
-    while (context[`__fn${i}`]) i++;
-    const shallowKey = `__fn${i}`;
+  const call = <C, T>(context: C, fn: Function, ...args: T[]) => {
+    const sf = Symbol();
 
-    Object.defineProperty(context, shallowKey, {
-      value: fn,
+    Object.defineProperty(context, sf, {
       enumerable: false,
       configurable: true,
+      writable: true,
+      value: fn,
     });
 
-    const result = context[shallowKey](...args);
-
-    delete context[shallowKey];
+    const sc: C & { [sf]?: Function } = context;
+    const result = sc[sf]?.(...args);
+    delete sc[sf];
 
     return result;
   };