Merge pull request #104 from koloml/feature/testing-configuration-controller

Added tests for ConfigurationController class

package-lock.json

@@ -17,6 +17,7 @@
                 "@sveltejs/kit": "^2.17.2",
                 "@sveltejs/vite-plugin-svelte": "^5.0.3",
                 "@types/chrome": "^0.0.304",
+                "@types/node": "^22.13.5",
                 "@vitest/coverage-v8": "^3.0.6",
                 "cheerio": "^1.0.0",
                 "jsdom": "^26.0.0",
@@ -814,6 +815,16 @@
             "dev": true,
             "license": "MIT"
         },
+        "node_modules/@types/node": {
+            "version": "22.13.5",
+            "resolved": "https://registry.npmjs.org/@types/node/-/node-22.13.5.tgz",
+            "integrity": "sha512-+lTU0PxZXn0Dr1NBtC7Y8cR21AJr87dLLU953CWA6pMxxv/UDc7jYAY90upcrie1nRcD6XNG5HOYEDtgW5TxAg==",
+            "dev": true,
+            "license": "MIT",
+            "dependencies": {
+                "undici-types": "~6.20.0"
+            }
+        },
         "node_modules/@vitest/coverage-v8": {
             "version": "3.0.6",
             "resolved": "https://registry.npmjs.org/@vitest/coverage-v8/-/coverage-v8-3.0.6.tgz",
@@ -2972,6 +2983,13 @@
                 "node": ">=18.17"
             }
         },
+        "node_modules/undici-types": {
+            "version": "6.20.0",
+            "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.20.0.tgz",
+            "integrity": "sha512-Ny6QZ2Nju20vw1SRHe3d9jVu6gJ+4e3+MMpqu7pqE5HT6WsTSlce++GQmK5UXS8mzV8DSYHrQH+Xrf2jVcuKNg==",
+            "dev": true,
+            "license": "MIT"
+        },
         "node_modules/vite": {
             "version": "6.1.0",
             "resolved": "https://registry.npmjs.org/vite/-/vite-6.1.0.tgz",

package.json

@@ -17,6 +17,7 @@
         "@sveltejs/kit": "^2.17.2",
         "@sveltejs/vite-plugin-svelte": "^5.0.3",
         "@types/chrome": "^0.0.304",
+        "@types/node": "^22.13.5",
         "@vitest/coverage-v8": "^3.0.6",
         "cheerio": "^1.0.0",
         "jsdom": "^26.0.0",

src/lib/extension/ConfigurationController.ts

@@ -2,12 +2,16 @@ import StorageHelper, { type StorageChangeSubscriber } from "$lib/browser/Storag
 
 export default class ConfigurationController {
   readonly #configurationName: string;
+  readonly #storage: StorageHelper;
 
   /**
    * @param {string} configurationName Name of the configuration to work with.
+   * @param {StorageHelper} [storage] Selected storage where the settings are stored in. If not provided, local storage
+   * is used.
    */
-  constructor(configurationName: string) {
+  constructor(configurationName: string, storage: StorageHelper = new StorageHelper(chrome.storage.local)) {
     this.#configurationName = configurationName;
+    this.#storage = storage;
   }
 
   /**
@@ -19,7 +23,7 @@ export default class ConfigurationController {
    * @return The setting value or the default value if the setting does not exist.
    */
   async readSetting<Type = any, DefaultType = any>(settingName: string, defaultValue: DefaultType | null = null): Promise<Type | DefaultType> {
-    const settings = await ConfigurationController.#storageHelper.read(this.#configurationName, {});
+    const settings = await this.#storage.read(this.#configurationName, {});
     return settings[settingName] ?? defaultValue;
   }
 
@@ -32,11 +36,11 @@ export default class ConfigurationController {
    * @return {Promise<void>}
    */
   async writeSetting(settingName: string, value: any): Promise<void> {
-    const settings = await ConfigurationController.#storageHelper.read(this.#configurationName, {});
+    const settings = await this.#storage.read(this.#configurationName, {});
 
     settings[settingName] = value;
 
-    ConfigurationController.#storageHelper.write(this.#configurationName, settings);
+    this.#storage.write(this.#configurationName, settings);
   }
 
   /**
@@ -45,11 +49,11 @@ export default class ConfigurationController {
    * @param {string} settingName Setting name to delete.
    */
   async deleteSetting(settingName: string): Promise<void> {
-    const settings = await ConfigurationController.#storageHelper.read(this.#configurationName, {});
+    const settings = await this.#storage.read(this.#configurationName, {});
 
     delete settings[settingName];
 
-    ConfigurationController.#storageHelper.write(this.#configurationName, settings);
+    this.#storage.write(this.#configurationName, settings);
   }
 
   /**
@@ -69,10 +73,8 @@ export default class ConfigurationController {
       callback(changes[this.#configurationName].newValue);
     }
 
-    ConfigurationController.#storageHelper.subscribe(subscriber);
+    this.#storage.subscribe(subscriber);
 
-    return () => ConfigurationController.#storageHelper.unsubscribe(subscriber);
+    return () => this.#storage.unsubscribe(subscriber);
   }
-
-  static #storageHelper = new StorageHelper(chrome.storage.local);
 }

tests/lib/components/base/BaseComponent.spec.ts

@@ -1,9 +1,6 @@
 import { BaseComponent } from "$lib/components/base/BaseComponent";
 import { getComponent } from "$lib/components/base/component-utils";
-
-function randomString() {
-  return crypto.randomUUID();
-}
+import { randomString } from "$tests/utils";
 
 describe('BaseComponent', () => {
   it('should bind the component to the element', () => {

tests/lib/extension/ConfigurationController.spec.ts

@@ -0,0 +1,186 @@
+import ConfigurationController from "$lib/extension/ConfigurationController";
+import ChromeStorageArea from "$tests/mocks/ChromeStorageArea";
+import StorageHelper from "$lib/browser/StorageHelper";
+import { randomString } from "$tests/utils";
+
+describe('ConfigurationController', () => {
+  const mockedStorageArea = new ChromeStorageArea();
+  const mockedStorageHelper = new StorageHelper(mockedStorageArea);
+
+  beforeEach(() => {
+    mockedStorageArea.clear();
+  });
+
+  it('should read setting from the field inside the configuration object', async () => {
+    const name = randomString();
+    const field = randomString();
+    const value = randomString();
+
+    mockedStorageArea.insertMockedData({
+      [name]: {
+        [field]: value
+      }
+    });
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+    const returnedValue = await controller.readSetting(field);
+
+    expect(returnedValue).toBe(value);
+  });
+
+  it('should return fallback value if configuration field does not exist', async () => {
+    const controller = new ConfigurationController(randomString(), mockedStorageHelper);
+    const fallbackValue = randomString();
+    const returnedValue = await controller.readSetting(randomString(), fallbackValue);
+
+    expect(returnedValue).toBe(fallbackValue);
+  });
+
+  it('should treat existing falsy values as existing values', async () => {
+    const name = randomString();
+
+    const falsyValuesStorage = [0, false, ''].reduce((record, value) => {
+      record[randomString()] = value;
+      return record;
+    }, {} as Record<string, any>);
+
+    mockedStorageArea.insertMockedData({
+      [name]: falsyValuesStorage
+    });
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+
+    for (const fieldName of Object.keys(falsyValuesStorage)) {
+      const returnedValue = await controller.readSetting(fieldName, randomString());
+
+      expect(returnedValue).toBe(falsyValuesStorage[fieldName]);
+    }
+  });
+
+  it('should write data to storage', async () => {
+    const name = randomString();
+    const field = randomString();
+    const value = randomString();
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+    await controller.writeSetting(field, value);
+
+    const expectedStructure = {
+      [name]: {
+        [field]: value,
+      }
+    };
+
+    expect(mockedStorageArea.mockedData).toEqual(expectedStructure);
+  });
+
+  it('should update existing object without touching other entries', async () => {
+    const name = randomString();
+    const existingField = randomString();
+    const existingValue = randomString();
+    const addedField = randomString();
+    const addedValue = randomString();
+
+    mockedStorageArea.insertMockedData({
+      [name]: {
+        [existingField]: existingValue,
+      }
+    });
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+    await controller.writeSetting(addedField, addedValue);
+
+    const expectedStructure = {
+      [name]: {
+        [existingField]: existingValue,
+        [addedField]: addedValue,
+      }
+    }
+
+    expect(mockedStorageArea.mockedData).toEqual(expectedStructure);
+  });
+
+  it('should delete setting from storage', async () => {
+    const name = randomString();
+    const field = randomString();
+    const value = randomString();
+
+    mockedStorageArea.insertMockedData({
+      [name]: {
+        [field]: value
+      }
+    });
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+    await controller.deleteSetting(field);
+
+    expect(mockedStorageArea.mockedData).toEqual({
+      [name]: {},
+    });
+  });
+
+  it('should return updated settings contents on changes', async () => {
+    const name = randomString();
+    const initialField = randomString();
+    const initialValue = randomString();
+
+    const addedField = randomString();
+    const addedValue = randomString();
+
+    const updatedInitialValue = randomString();
+    const receivedData: Record<string, string>[] = [];
+
+    mockedStorageArea.insertMockedData({
+      [name]: {
+        [initialField]: initialValue,
+      }
+    });
+
+    const controller = new ConfigurationController(name, mockedStorageHelper);
+    const subscriber = vi.fn((storageState: Record<string, string>) => {
+      receivedData.push(JSON.parse(JSON.stringify(storageState)));
+    });
+
+    controller.subscribeToChanges(subscriber);
+
+    await controller.writeSetting(addedField, addedValue);
+    await controller.writeSetting(initialField, updatedInitialValue);
+    await controller.deleteSetting(initialField);
+
+    expect(subscriber).toBeCalledTimes(3);
+
+    const expectedData: Record<string, string>[] = [
+      // First, initial data and added field are present
+      {
+        [initialField]: initialValue,
+        [addedField]: addedValue,
+      },
+      // Then we get new value on initial field
+      {
+        [initialField]: updatedInitialValue,
+        [addedField]: addedValue,
+      },
+      // And then the initial value is dropped
+      {
+        [addedField]: addedValue,
+      }
+    ];
+
+    expect(receivedData).toEqual(expectedData);
+  });
+
+  it('should stop listening once unsubscribe called', async () => {
+    const controller = new ConfigurationController(randomString(), mockedStorageHelper);
+    const subscriber = vi.fn();
+
+    const unsubscribe = controller.subscribeToChanges(subscriber);
+
+    await controller.writeSetting(randomString(), randomString());
+    expect(subscriber).toBeCalledTimes(1);
+
+    unsubscribe();
+    subscriber.mockReset();
+    await controller.writeSetting(randomString(), randomString())
+    expect(subscriber).not.toBeCalled();
+  });
+});

tests/mocks/ChromeEvent.ts

@@ -1,9 +1,9 @@
 export default class ChromeEvent<T extends Function> implements chrome.events.Event<T> {
-    addListener = vi.fn();
-    getRules = vi.fn();
-    hasListener = vi.fn();
-    removeRules = vi.fn();
-    addRules = vi.fn();
-    removeListener = vi.fn();
-    hasListeners = vi.fn();
+  addListener = vi.fn();
+  getRules = vi.fn();
+  hasListener = vi.fn();
+  removeRules = vi.fn();
+  addRules = vi.fn();
+  removeListener = vi.fn();
+  hasListeners = vi.fn();
 }

tests/mocks/ChromeLocalStorageArea.ts

@@ -1,5 +1,5 @@
 import ChromeStorageArea from "$tests/mocks/ChromeStorageArea";
 
 export class ChromeLocalStorageArea extends ChromeStorageArea implements chrome.storage.LocalStorageArea {
-    QUOTA_BYTES = 100000;
+  QUOTA_BYTES = 100000;
 }

tests/mocks/ChromeStorageArea.ts

@@ -1,4 +1,4 @@
-import ChromeEvent from "./ChromeEvent";
+import ChromeStorageChangeEvent from "$tests/mocks/ChromeStorageChangeEvent";
 
 type ChangedEventCallback = (changes: chrome.storage.StorageChange) => void
 
@@ -13,8 +13,20 @@ export default class ChromeStorageArea implements chrome.storage.StorageArea {
     })
   });
   set = vi.fn((...args: any[]): Promise<void> => {
-    return new Promise((resolve, reject) => {
+    return new Promise((resolve) => {
+      const change: Record<string, chrome.storage.StorageChange> = {};
+      const setter = args[0];
+
+      for (let targetKey of Object.keys(setter)) {
+        change[targetKey] = {
+          oldValue: this.#mockedData[targetKey] ?? undefined,
+          newValue: setter[targetKey],
+        };
+      }
+
       this.#mockedData = Object.assign(this.#mockedData, args[0]);
+      this.onChanged.mockEmitStorageChange(change);
+
       resolve();
     })
   });
@@ -23,7 +35,16 @@ export default class ChromeStorageArea implements chrome.storage.StorageArea {
       const key = args[0];
 
       if (typeof key === 'string') {
+        const change: chrome.storage.StorageChange = {
+          oldValue: this.#mockedData[key],
+        };
+
         delete this.#mockedData[key];
+
+        this.onChanged.mockEmitStorageChange({
+          [key]: change
+        });
+
         resolve();
       }
 
@@ -58,7 +79,7 @@ export default class ChromeStorageArea implements chrome.storage.StorageArea {
     });
   });
   setAccessLevel = vi.fn();
-  onChanged = new ChromeEvent<ChangedEventCallback>();
+  onChanged = new ChromeStorageChangeEvent();
   getKeys = vi.fn();
 
   insertMockedData(data: Record<string, any>) {

tests/mocks/ChromeStorageChangeEvent.ts

@@ -0,0 +1,27 @@
+import ChromeEvent from "$tests/mocks/ChromeEvent";
+import { EventEmitter } from "node:events";
+
+type MockedStorageChanges = Record<string, chrome.storage.StorageChange>;
+type IncomingStorageChangeListener = (changes: MockedStorageChanges) => void;
+
+const storageChangeEvent = Symbol();
+
+interface StorageChangeEventMap {
+  [storageChangeEvent]: [MockedStorageChanges];
+}
+
+export default class ChromeStorageChangeEvent extends ChromeEvent<IncomingStorageChangeListener> {
+  #emitter = new EventEmitter<StorageChangeEventMap>();
+
+  addListener = vi.fn((actualListener: IncomingStorageChangeListener) => {
+    this.#emitter.addListener(storageChangeEvent, actualListener);
+  });
+
+  removeListener = vi.fn((actualListener: IncomingStorageChangeListener) => {
+    this.#emitter.removeListener(storageChangeEvent, actualListener);
+  });
+
+  mockEmitStorageChange(changes: MockedStorageChanges) {
+    this.#emitter.emit(storageChangeEvent, changes);
+  }
+}

tests/utils.ts

@@ -0,0 +1,7 @@
+export function randomString(): string {
+  return crypto.randomUUID();
+}
+
+export function copyValue<T>(object: T): T {
+  return JSON.parse(JSON.stringify(object));
+}