How to fix 'X' cannot be imported, as it is not exported from 'Y' in TypeScript

// In module Y.ts - CHECK THIS FILE
// ❌ WRONG - missing export keyword
const someValue = 42;
function helper() { return "help"; }
type MyType = { id: string };

// ✅ CORRECT - add export keyword
export const someValue = 42;
export function helper() { return "help"; }
export type MyType = { id: string };

// ✅ CORRECT - export at the end
const someValue = 42;
function helper() { return "help"; }
type MyType = { id: string };

export { someValue, helper, type MyType };

// In module Y.ts
export default function mainFunction() { /* ... */ }  // Default export
export const helper = () => { /* ... */ };           // Named export

// In importing file
// ❌ WRONG - using named import for default export
import { mainFunction } from "./Y";

// ✅ CORRECT - default import for default export
import mainFunction from "./Y";

// ✅ CORRECT - named import for named export
import { helper } from "./Y";

// ✅ CORRECT - mixed imports
import mainFunction, { helper } from "./Y";

// In module Y.ts
export type User = { id: string; name: string };    // Type export
export const createUser = () => ({ id: "1", name: "Alice" });  // Value export

// In importing file
// ✅ CORRECT - import type for types
import type { User } from "./Y";

// ✅ CORRECT - regular import for values
import { createUser } from "./Y";

// ✅ CORRECT - mixed import
import { createUser, type User } from "./Y";

// ❌ WRONG - trying to use type as value
import type { User } from "./Y";
const user: User = createUser();  // ✅ OK - type position
console.log(User);                // ❌ Error - value position

// In the package's package.json
{
  "name": "some-package",
  "exports": {
    ".": "./dist/index.js",
    "./utils": "./dist/utils.js"  // Only these paths are allowed
  }
}

// ✅ These will work
import { something } from "some-package";
import { util } from "some-package/utils";

// ❌ These may fail if not in exports field
import { internal } from "some-package/dist/internal.js";
import { secret } from "some-package/src/secret.ts";

// In Y.ts - currently a script (no imports/exports)
const value = 42;
function helper() { return "help"; }

// ❌ This file won't allow imports because it's not a module

// ✅ Add any export to make it a module
export const value = 42;
function helper() { return "help"; }

// OR add an empty export
const value = 42;
function helper() { return "help"; }
export {};  // Makes file a module while not exporting anything

// In module Y.ts
export const myValue = 42;
export const MyComponent = () => <div>Hello</div>;

// In importing file
// ❌ WRONG - case mismatch
import { myvalue } from "./Y";      // Should be myValue
import { mycomponent } from "./Y";  // Should be MyComponent

// ❌ WRONG - typo
import { myVal } from "./Y";        // Should be myValue

// ✅ CORRECT - exact match
import { myValue, MyComponent } from "./Y";