[weak-memoize] Convert to TypeScript

.changeset/loud-hairs-approve.md

@@ -2,4 +2,4 @@
 '@emotion/weak-memoize': minor
 ---
 
-Convert to TypeScript and emit definitions based on the code
+Source code has been migrated to TypeScript. From now on type declarations will be emitted based on that, instead of being hand-written.

packages/memoize/package.json

@@ -18,8 +18,7 @@
   },
   "files": [
     "src",
-    "dist",
-    "types/*.d.ts"
+    "dist"
   ],
   "browser": {
     "./dist/emotion-memoize.cjs.js": "./dist/emotion-memoize.browser.cjs.js",

packages/weak-memoize/package.json

@@ -18,8 +18,7 @@
   },
   "files": [
     "src",
-    "dist",
-    "types/*.d.ts"
+    "dist"
   ],
   "browser": {
     "./dist/emotion-weak-memoize.cjs.js": "./dist/emotion-weak-memoize.browser.cjs.js",

packages/weak-memoize/src/index.ts

@@ -4,9 +4,9 @@ let weakMemoize = function <Arg extends object, Return>(
   let cache = new WeakMap<Arg, Return>()
   return (arg: Arg) => {
     if (cache.has(arg)) {
-      // Cast to `Return` because we just checked that the cache `has` it
+      // Use non-null assertion because we just checked that the cache `has` it
       // This allows us to remove `undefined` from the return value
-      return cache.get(arg) as Return
+      return cache.get(arg)!
     }
     let ret = func(arg)
     cache.set(arg, ret)

packages/weak-memoize/types/index.d.ts

@@ -0,0 +1,3 @@
+// TypeScript Version: 2.2
+
+export { default } from '../src'

packages/weak-memoize/types/tslint.json

@@ -18,6 +18,7 @@
     ],
 
     "no-unnecessary-generics": false,
-    "strict-export-declare-modifiers": false
+    "strict-export-declare-modifiers": false,
+    "no-default-import": false
   }
 }