wip: 개체 작업 진행

@sammo/util/src/index.ts

@@ -2,6 +2,7 @@ export * from "./bsonify.js"
 export * from "./jsonify.js"
 export * from "./error.js"
 export * from "./unwrap.js"
+export * from "./must.js"
 export * from "./types.js"
 export * from "./web.js"
 

@sammo/util/src/must.ts

@@ -0,0 +1,25 @@
+import type { Nullable } from './types.js';
+import { NotNullExpected } from "./error.js";
+
+export function must<T>(result: Nullable<T>): T {
+    if (result === null || result === undefined) {
+        throw new NotNullExpected();
+    }
+    return result;
+}
+
+export function must_any<T>(result: Nullable<unknown>): T {
+    if (result === null || result === undefined) {
+        throw new NotNullExpected();
+    }
+    return result as T;
+}
+
+type ErrType<T> = { new(msg?: string): T }
+
+export function must_err<T, ErrT extends Error>(result: Nullable<T>, errType: ErrType<ErrT>, errMsg?: string): T {
+    if (result === null || result === undefined) {
+        throw new errType(errMsg);
+    }
+    return result;
+}