Remove browser-specific memoization

Author: rtsao

src/__tests__/memoize.js

@@ -30,5 +30,15 @@ test('memoize', t => {
   t.equal(memoizedB(mockCtx), 1, 'memoizes correctly');
   t.equal(memoized(mockCtx), 1, 'calls function when it has no value');
   t.equal(memoized(mockCtx), 1, 'memoizes correctly');
+
+  // New context object should cause new calculation
+  const mockCtx2: Context = ({}: any);
+  t.equal(memoized(mockCtx2), 2, 'calls function when it has no value');
+  t.equal(memoized(mockCtx2), 2, 'memoizes correctly');
+  t.equal(memoizedB(mockCtx2), 2, 'calls function when it has no value');
+  t.equal(memoizedB(mockCtx2), 2, 'memoizes correctly');
+  t.equal(memoized(mockCtx2), 2, 'calls function when it has no value');
+  t.equal(memoized(mockCtx2), 2, 'memoizes correctly');
+
   t.end();
 });

src/memoize.js

@@ -11,34 +11,13 @@ import type {Context} from './types.js';
 type MemoizeFn<A> = (ctx: Context) => A;
 
 export function memoize<A>(fn: MemoizeFn<A>): MemoizeFn<A> {
-  if (__BROWSER__) {
-    return browserMemoize(fn);
-  }
-
   const wm = new WeakMap();
   return ctx => {
     if (wm.has(ctx)) {
-      return ((wm.get(ctx): any): A); // Refinement doesn't seem to work
-    } else {
-      const result = fn(ctx);
-      wm.set(ctx, result);
-      return result;
-    }
-  };
-}
-
-/**
- * There is only ever a single ctx object in the browser.
- * Therefore we can use a simple memoization function.
- */
-function browserMemoize<A>(fn: MemoizeFn<A>): MemoizeFn<A> {
-  let memoized;
-  let called = false;
-  return ctx => {
-    if (!called) {
-      memoized = fn(ctx);
-      called = true;
+      return ((wm.get(ctx): any): A); // Refinement with `has` doesn't seem to work
     }
-    return memoized;
+    const result = fn(ctx);
+    wm.set(ctx, result);
+    return result;
   };
 }