Files
privacy.sexy/tests/unit/presentation/injectionSymbols.ts
undergroundwires 7770a9b521 Refactor DI for simplicity and type safety
This commit improves the dependency injection mechanism by introducing a
custom `injectKey` function.

Key improvements are:

- Enforced type consistency during dependency registration and
  instantiation.
- Simplified injection process, abstracting away the complexity with a
  uniform API, regardless of the dependency's lifetime.
- Eliminated the possibility of `undefined` returns during dependency
  injection, promoting fail-fast behavior.
- Removed the necessity for type casting to `symbol` for injection keys
  in unit tests by using existing types.
- Consalidated imports, combining keys and injection functions in one
  `import` statement.
2023-11-09 13:17:38 +01:00

79 lines
2.9 KiB
TypeScript

import { describe, it, expect } from 'vitest';
import { InjectionKeySelector, InjectionKeys, injectKey } from '@/presentation/injectionSymbols';
import { getAbsentObjectTestCases } from '../shared/TestCases/AbsentTests';
describe('injectionSymbols', () => {
describe('InjectionKeys', () => {
Object.entries(InjectionKeys).forEach(([key, injectionKey]) => {
describe(`symbol for ${injectionKey.key.toString()}`, () => {
it('should be a symbol type', () => {
// arrange
const actualKey = injectionKey.key;
const expectedType = Symbol;
// act
// assert
expect(actualKey).to.be.instanceOf(expectedType);
});
it(`should have a description matching the key "${injectionKey.key.toString()}"`, () => {
// arrange
const actualKey = injectionKey.key;
const expected = key;
// act
const actual = actualKey.description;
// assert
expect(expected).to.equal(actual);
});
});
});
});
describe('injectKey', () => {
it('returns the correct value for singleton keys', () => {
// arrange
const mockValue = { someProperty: 'someValue' };
// act
const mockInject = () => mockValue;
const result = injectKey((keys) => keys.useApplication, mockInject);
// assert
expect(result).to.equal(mockValue);
});
it('invokes and returns result from factory function for transient keys', () => {
// arrange
const mockValue = { anotherProperty: 'anotherValue' };
const mockFactory = () => mockValue;
const mockInject = () => mockFactory;
// act
const result = injectKey((keys) => keys.useCollectionState, mockInject);
// assert
expect(result).to.equal(mockValue);
});
describe('throws error when no value is provided for a key', () => {
// arrange
const testScenarios: ReadonlyArray<{
readonly name: string,
readonly act: (selector: InjectionKeySelector<unknown>) => void,
}> = getAbsentObjectTestCases().flatMap((absentTest) => [
{
name: `singleton factory: ${absentTest.absentValue}`,
act: (selector) => injectKey(selector, () => (() => absentTest.absentValue)),
},
{
name: `transient: ${absentTest.absentValue}`,
act: (selector) => injectKey(selector, () => absentTest.absentValue),
},
]);
testScenarios.forEach((testCase) => {
it(testCase.name, () => {
// arrange
const key = InjectionKeys.useRuntimeEnvironment;
const expectedError = `Failed to inject value for key: ${key.key.description}`;
const selector: InjectionKeySelector<typeof key> = () => key;
// act
const act = () => testCase.act(selector);
// assert
expect(act).to.throw(expectedError);
});
});
});
});
});