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-rw-r--r--src/utils/proxyLazy.ts60
1 files changed, 45 insertions, 15 deletions
diff --git a/src/utils/proxyLazy.ts b/src/utils/proxyLazy.ts
index 0e01540..364dd56 100644
--- a/src/utils/proxyLazy.ts
+++ b/src/utils/proxyLazy.ts
@@ -16,9 +16,46 @@
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
-import { makeLazy } from "./misc";
+// Proxies demand that these properties be unmodified, so proxyLazy
+// will always return the function default for them.
+const unconfigurable = ["arguments", "caller", "prototype"];
-const ProxyDummy = function () { };
+const handler: ProxyHandler<any> = {};
+
+for (const method of [
+ "apply",
+ "construct",
+ "defineProperty",
+ "deleteProperty",
+ "get",
+ "getOwnPropertyDescriptor",
+ "getPrototypeOf",
+ "has",
+ "isExtensible",
+ "ownKeys",
+ "preventExtensions",
+ "set",
+ "setPrototypeOf"
+]) {
+ handler[method] =
+ (target: any, ...args: any[]) => Reflect[method](target.get(), ...args);
+}
+
+handler.ownKeys = target => {
+ const v = target.get();
+ const keys = Reflect.ownKeys(v);
+ for (const key of unconfigurable) {
+ if (!keys.includes(key)) keys.push(key);
+ }
+ return keys;
+};
+
+handler.getOwnPropertyDescriptor = (target, p) => {
+ if (typeof p === "string" && unconfigurable.includes(p))
+ return Reflect.getOwnPropertyDescriptor(target, p);
+
+ return Reflect.getOwnPropertyDescriptor(target.get(), p);
+};
/**
* Wraps the result of {@see makeLazy} in a Proxy you can consume as if it wasn't lazy.
@@ -30,17 +67,10 @@ const ProxyDummy = function () { };
* @example const mod = proxyLazy(() => findByProps("blah")); console.log(mod.blah);
*/
export function proxyLazy<T>(factory: () => T): T {
- const lazy = makeLazy(factory);
-
- return new Proxy(ProxyDummy, {
- get: (_, prop) => lazy()[prop],
- set: (_, prop, value) => lazy()[prop] = value,
- has: (_, prop) => prop in lazy(),
- apply: (_, $this, args) => (lazy() as Function).apply($this, args),
- ownKeys: () => Reflect.ownKeys(lazy() as object),
- construct: (_, args) => Reflect.construct(lazy() as Function, args),
- deleteProperty: (_, prop) => delete lazy()[prop],
- defineProperty: (_, property, attributes) => !!Object.defineProperty(lazy(), property, attributes),
- getPrototypeOf: () => Object.getPrototypeOf(lazy())
- }) as any as T;
+ const proxyDummy: { (): void; cachedValue?: T; get(): T; } = function () { };
+
+ proxyDummy.cachedValue = void 0;
+ proxyDummy.get = () => proxyDummy.cachedValue ??= factory();
+
+ return new Proxy(proxyDummy, handler) as any;
}