[LAB2] 313551150

lab2/main_test.js

@@ -1,6 +1,177 @@
 const test = require('node:test');
 const assert = require('assert');
+const fs = require('fs');
 const { Application, MailSystem } = require('./main');
 
-// TODO: write your tests here
-// Remember to use Stub, Mock, and Spy when necessary
+// Helper: create Application without triggering file read error.
+// Override getNames so that it immediately returns a resolved promise.
+function createTestApplicationWithoutFileRead() {
+  const originalGetNames = Application.prototype.getNames;
+  Application.prototype.getNames = function() {
+    return Promise.resolve([this.people, this.selected]);
+  };
+  const app = new Application();
+  // Immediately restore the original getNames for any later use.
+  Application.prototype.getNames = originalGetNames;
+  return app;
+}
+
+// Utility function for a small delay.
+function delay(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+// Test: Application.getNames should read names from file.
+test('Application.getNames should read names from file', async () => {
+  const testData = "Alice\nBob\nCharlie";
+  fs.writeFileSync('name_list.txt', testData, 'utf8');
+
+  // Use the real getNames.
+  const app = new Application();
+  const [people, selected] = await app.getNames();
+  assert.deepStrictEqual(people, ['Alice', 'Bob', 'Charlie']);
+
+  fs.unlinkSync('name_list.txt');
+});
+
+// Test: Application constructor should initialize people and selected.
+test('Application constructor should initialize people and selected', async () => {
+  const testData = "Alice\nBob";
+  fs.writeFileSync('name_list.txt', testData, 'utf8');
+
+  const app = new Application();
+  // Wait a bit for the asynchronous constructor to complete.
+  await delay(20);
+  assert.deepStrictEqual(app.people, ['Alice', 'Bob']);
+  assert.deepStrictEqual(app.selected, []);
+
+  fs.unlinkSync('name_list.txt');
+});
+
+// Test: getRandomPerson returns a valid name.
+test('Application.getRandomPerson should return a valid name', () => {
+  const app = createTestApplicationWithoutFileRead();
+  app.people = ['Alice', 'Bob', 'Charlie'];
+
+  const originalRandom = Math.random;
+  Math.random = () => 0.5; // floor(0.5 * 3) = 1, expecting 'Bob'
+
+  const person = app.getRandomPerson();
+  assert.strictEqual(person, 'Bob');
+
+  Math.random = originalRandom;
+});
+
+// Test: selectNextPerson avoids duplicate selections.
+test('Application.selectNextPerson should avoid duplicates', () => {
+  const app = createTestApplicationWithoutFileRead();
+  app.people = ['Alice', 'Bob', 'Charlie'];
+  app.selected = ['Alice'];
+
+  const originalRandom = Math.random;
+  // Force Math.random to return a value that selects 'Charlie'
+  Math.random = () => 0.8; // floor(0.8 * 3) = 2 -> 'Charlie'
+
+  const person = app.selectNextPerson();
+  assert.strictEqual(person, 'Charlie');
+  assert.strictEqual(app.selected.length, 2);
+
+  Math.random = originalRandom;
+});
+
+// Test: selectNextPerson returns null if all persons have been selected.
+test('Application.selectNextPerson should return null if all selected', () => {
+  const app = createTestApplicationWithoutFileRead();
+  app.people = ['Alice', 'Bob'];
+  app.selected = ['Alice', 'Bob'];
+
+  const person = app.selectNextPerson();
+  assert.strictEqual(person, null);
+});
+
+// Test: selectNextPerson loops until a non-duplicate is selected.
+test('Application.selectNextPerson should loop until a non-duplicate is selected', () => {
+  const app = createTestApplicationWithoutFileRead();
+  app.people = ['Alice', 'Bob', 'Charlie'];
+  app.selected = ['Alice']; // 'Alice' already selected
+
+  // Override getRandomPerson to simulate a duplicate on first call,
+  // then a unique name on the second call.
+  let callCount = 0;
+  app.getRandomPerson = function() {
+    callCount++;
+    if (callCount === 1) {
+      return 'Alice'; // duplicate value
+    } else {
+      return 'Bob'; // new value
+    }
+  };
+
+  const selectedPerson = app.selectNextPerson();
+  assert.strictEqual(selectedPerson, 'Bob');
+  assert.strictEqual(callCount, 2); // getRandomPerson should be called twice
+});
+
+// Test: MailSystem.write generates the correct mail content.
+test('MailSystem.write should generate correct mail content', () => {
+  const mailSystem = new MailSystem();
+  const content = mailSystem.write('Alice');
+  assert.strictEqual(content, 'Congrats, Alice!');
+});
+
+// Test: MailSystem.send returns true when Math.random is high.
+test('MailSystem.send should return true when Math.random is high', () => {
+  const mailSystem = new MailSystem();
+  const originalRandom = Math.random;
+  Math.random = () => 0.9; // Simulate success
+
+  const result = mailSystem.send('Alice', 'Congrats, Alice!');
+  assert.strictEqual(result, true);
+
+  Math.random = originalRandom;
+});
+
+// Test: MailSystem.send returns false when Math.random is low.
+test('MailSystem.send should return false when Math.random is low', () => {
+  const mailSystem = new MailSystem();
+  const originalRandom = Math.random;
+  Math.random = () => 0.1; // Simulate failure
+
+  const result = mailSystem.send('Alice', 'Congrats, Alice!');
+  assert.strictEqual(result, false);
+
+  Math.random = originalRandom;
+});
+
+// Test: notifySelected calls write and send for each selected person.
+test('Application.notifySelected should call write and send for each person', () => {
+  const app = createTestApplicationWithoutFileRead();
+  app.selected = ['Alice', 'Bob'];
+
+  let writeCalls = [];
+  let sendCalls = [];
+
+  const originalWrite = app.mailSystem.write;
+  const originalSend = app.mailSystem.send;
+
+  // Override write and send to record calls.
+  app.mailSystem.write = function(name) {
+    writeCalls.push(name);
+    return 'Congrats!';
+  };
+
+  app.mailSystem.send = function(name, context) {
+    sendCalls.push({ name, context });
+    return true;
+  };
+
+  app.notifySelected();
+
+  assert.deepStrictEqual(writeCalls, ['Alice', 'Bob']);
+  assert.strictEqual(sendCalls.length, 2);
+  assert.deepStrictEqual(sendCalls[0], { name: 'Alice', context: 'Congrats!' });
+  assert.deepStrictEqual(sendCalls[1], { name: 'Bob', context: 'Congrats!' });
+
+  app.mailSystem.write = originalWrite;
+  app.mailSystem.send = originalSend;
+});