[NoQA] chore(tests): unified utilities for mocking collections

package.json

@@ -189,6 +189,7 @@
     "@dword-design/eslint-plugin-import-alias": "^4.0.8",
     "@electron/notarize": "^2.1.0",
     "@jest/globals": "^29.5.0",
+    "@ngneat/falso": "^7.1.1",
     "@octokit/core": "4.0.4",
     "@octokit/plugin-paginate-rest": "3.1.0",
     "@octokit/plugin-throttling": "4.1.0",

tests/README.md

@@ -15,6 +15,36 @@
 - To simulate a network request succeeding or failing we can mock the expected response first and then manually trigger the action that calls that API command.
 - [Mocking the response of `HttpUtils.xhr()`](https://github.com/Expensify/App/blob/ca2fa88a5789b82463d35eddc3d57f70a7286868/tests/actions/SessionTest.js#L25-L32) is the best way to simulate various API conditions so we can verify whether a result occurs or not.
 
+## Mocking collections / collection items
+
+When unit testing an interface with Jest/performance testing with Reassure you might need to work with collections of data. These often get tricky to generate and maintain. To help with this we have a few helper methods located in `tests/utils/collections/`.
+
+- `createCollection()` - Creates a collection of data (`Record<string, T>`) with a given number of items (default=500). This is useful for eg. testing the performance of a component with a large number of items. You can use it to populate Onyx.
+- `createRandom*()` - like `createRandomPolicy`, these functions are responsible for generating a randomised object of the given type. You can use them as your defaults when calling `createCollection()` or as standalone utilities.
+
+Basic example:
+```ts
+const policies = createCollection<Policy>(item => `policies_${item.id}`, createRandomPolicy);
+
+/**
+    Output:
+    {
+        "policies_0": policyItem0,
+        "policies_1": policyItem1,
+        ...
+    }
+*/
+```
+
+Example with overrides:
+
+```ts
+const policies = createCollection<Policy>(
+    item => `policies_${item.id}`,
+    index => ({ ...createRandomPolicy(index), isPinned: true })
+);
+```
+
 ## Mocking `node_modules`, user modules, and what belongs in `jest/setup.js`
 
 If you need to mock a library that exists in `node_modules` then add it to the `__mocks__` folder in the root of the project. More information about this [here](https://jestjs.io/docs/manual-mocks#mocking-node-modules). If you need to mock an individual library you should create a mock module in a `__mocks__` subdirectory adjacent to the library as explained [here](https://jestjs.io/docs/manual-mocks#mocking-user-modules). However, keep in mind that when you do this you also must manually require the mock by calling something like `jest.mock('../../src/libs/Log');` at the top of an individual test file. If every test in the app will need something to be mocked that's a good case for adding it to `jest/setup.js`, but we should generally avoid adding user mocks or `node_modules` mocks to this file. Please use the `__mocks__` subdirectories wherever appropriate.

tests/utils/collections/createCollection.ts

@@ -0,0 +1,11 @@
+export default function createCollection<T>(createKey: (item: T, index: number) => string, createItem: (index: number) => T, length = 500): Record<string, T> {
+    const map: Record<string, T> = {};
+
+    for (let i = 0; i < length; i++) {
+        const item = createItem(i);
+        const itemKey = createKey(item, i);
+        map[itemKey] = item;
+    }
+
+    return map;
+}

tests/utils/collections/policies.ts

@@ -0,0 +1,26 @@
+import {rand, randAvatar, randBoolean, randCurrencyCode, randEmail, randPastDate, randWord} from '@ngneat/falso';
+import CONST from '@src/CONST';
+import type {Policy} from '@src/types/onyx';
+
+export default function createRandomPolicy(index: number): Policy {
+    return {
+        id: index.toString(),
+        name: randWord(),
+        type: rand(Object.values(CONST.POLICY.TYPE)),
+        areChatRoomsEnabled: randBoolean(),
+        autoReporting: randBoolean(),
+        isPolicyExpenseChatEnabled: randBoolean(),
+        autoReportingFrequency: rand(Object.values(CONST.POLICY.AUTO_REPORTING_FREQUENCIES)),
+        outputCurrency: randCurrencyCode(),
+        role: rand(Object.values(CONST.POLICY.ROLE)),
+        owner: randEmail(),
+        ownerAccountID: index,
+        avatar: randAvatar(),
+        isFromFullPolicy: randBoolean(),
+        lastModified: randPastDate().toISOString(),
+        pendingAction: rand(Object.values(CONST.RED_BRICK_ROAD_PENDING_ACTION)),
+        errors: {},
+        customUnits: {},
+        errorFields: {},
+    };
+}

tests/utils/collections/reports.ts

@@ -0,0 +1,22 @@
+import {rand, randBoolean, randCurrencyCode, randEmail, randWord} from '@ngneat/falso';
+import CONST from '@src/CONST';
+import type {Report} from '@src/types/onyx';
+
+export default function createRandomReport(index: number): Report {
+    return {
+        reportID: index.toString(),
+        chatType: rand(Object.values(CONST.REPORT.CHAT_TYPE)),
+        currency: randCurrencyCode(),
+        displayName: randWord(),
+        hasDraft: randBoolean(),
+        ownerEmail: randEmail(),
+        ownerAccountID: index,
+        isPinned: randBoolean(),
+        isOptimisticReport: randBoolean(),
+        isOwnPolicyExpenseChat: randBoolean(),
+        isWaitingOnBankAccount: randBoolean(),
+        isLastMessageDeletedParentAction: randBoolean(),
+        policyID: index.toString(),
+        reportName: randWord(),
+    };
+}