feat(billing): refacto billing (#14243)

… prices for metered billing

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
Co-authored-by: Félix Malfait <felix@twenty.com>

packages/twenty-shared/src/utils/validation/__tests__/assertIsDefinedOrThrow.test.ts

@@ -0,0 +1,41 @@
+import { assertIsDefinedOrThrow } from '@/utils';
+
+describe('assertIsDefinedOrThrow', () => {
+  it('does not throw when value is defined (number)', () => {
+    expect(() => assertIsDefinedOrThrow(42)).not.toThrow();
+  });
+
+  it('does not throw when value is defined (false)', () => {
+    const v: boolean | undefined | null = false;
+    expect(() => assertIsDefinedOrThrow(v)).not.toThrow();
+  });
+
+  it('does not throw when value is defined (empty string)', () => {
+    const v: string | undefined | null = '';
+    expect(() => assertIsDefinedOrThrow(v)).not.toThrow();
+  });
+
+  it('throws the default error when value is undefined', () => {
+    expect(() => assertIsDefinedOrThrow(undefined)).toThrow('Value not defined');
+  });
+
+  it('throws the default error when value is null', () => {
+    expect(() => assertIsDefinedOrThrow(null)).toThrow('Value not defined');
+  });
+
+  it('throws the custom error instance when provided', () => {
+    const err = new TypeError('Custom');
+    expect(() => assertIsDefinedOrThrow(undefined, err)).toThrow(err);
+  });
+
+  it('narrows the type after assertion (compile-time check)', () => {
+    // eslint-disable-next-line prefer-arrow/prefer-arrow-functions
+    function expectString(s: string) {
+      expect(typeof s).toBe('string');
+    }
+    let maybe: string | undefined | null = 'ok';
+    assertIsDefinedOrThrow(maybe);
+    // After the assertion, TypeScript should treat `maybe` as `string`.
+    expectString(maybe);
+  });
+});

packages/twenty-shared/src/utils/validation/assertIsDefinedOrThrow.ts

@@ -0,0 +1,12 @@
+import { isDefined } from '@/utils';
+
+// https://github.com/microsoft/TypeScript/issues/34523
+// eslint-disable-next-line prefer-arrow/prefer-arrow-functions
+export function assertIsDefinedOrThrow<T>(
+  value: T | undefined | null,
+  exceptionToThrow: Error = new Error(
+    'Value not defined',
+  ),
+): asserts value is T {
+  if (!isDefined(value)) throw exceptionToThrow;
+}

packages/twenty-shared/src/utils/validation/index.ts

@@ -1,4 +1,5 @@
 export * from './isDefined';
+export * from './assertIsDefinedOrThrow';
 export * from './isValidLocale';
 export * from './isValidUuid';
 export * from './normalizeLocale';