Improve sample book collection validation and search

02-context-conversations/README.md

@@ -82,7 +82,7 @@ copilot
 ### Basic @ Patterns
 
 | Pattern | What It Does | Example Use |
-|---------|--------------|-------------|
+| --- | --- | --- |
 | `@file.py` | Reference a single file | `Review @samples/book-app-project/books.py` |
 | `@folder/` | Reference all files in a directory | `Review @samples/book-app-project/` |
 | `@file1.py @file2.py` | Reference multiple files | `Compare @samples/book-app-project/book_app.py @samples/book-app-project/books.py` |
@@ -475,26 +475,27 @@ No re-explaining. No re-reading files. Just continue working.
 
 <img src="assets/optional-going-deeper.png" alt="Abstract crystal cave in blue and purple tones representing deeper exploration of context concepts" width="800"/>
 
-These topics build on the essentials above. **Pick what interests you, or skip ahead to [Practice](#practice).**
+These topics build on the essentials above. **Pick what interests you, or skip ahead to** [**Practice**](#practice)**.**
 
 | I want to learn about... | Jump to |
-|---|---|
+| --- | --- |
 | Wildcard patterns and advanced session commands | [Additional @ Patterns & Session Commands](#additional-patterns) |
 | Building on context across multiple prompts | [Context-Aware Conversations](#context-aware-conversations) |
 | Token limits and `/compact` | [Understanding Context Windows](#understanding-context-windows) |
 | How to pick the right files to reference | [Choosing What to Reference](#choosing-what-to-reference) |
 | Analyzing screenshots and mockups | [Working with Images](#working-with-images) |
 
 <details>
-<summary><strong>Additional @ Patterns & Session Commands</strong></summary>
+<summary><strong>Additional @ Patterns &amp; Session Commands</strong></summary>
+
 <a id="additional-patterns"></a>
 
 ### Additional @ Patterns
 
 For power users, Copilot CLI supports wildcard patterns and image references:
 
 | Pattern | What It Does |
-|---------|--------------|
+| --- | --- |
 | `@folder/*.py` | All .py files in folder |
 | `@**/test_*.py` | Recursive wildcard: find all test files anywhere |
 | `@image.png` | Image file for UI review |
@@ -537,6 +538,7 @@ copilot
 
 <details>
 <summary><strong>Context-Aware Conversations</strong></summary>
+
 <a id="context-aware-conversations"></a>
 
 ### Context-Aware Conversations
@@ -577,6 +579,7 @@ Notice how each prompt builds on the previous work. This is the power of context
 
 <details>
 <summary><strong>Understanding Context Windows</strong></summary>
+
 <a id="understanding-context-windows"></a>
 
 ### Understanding Context Windows
@@ -637,7 +640,7 @@ copilot
 #### Context Efficiency Tips
 
 | Situation | Action | Why |
-|-----------|--------|-----|
+| --- | --- | --- |
 | Starting new topic | `/clear` | Removes irrelevant context |
 | Went down wrong path | `/rewind` | Roll back conversation (and optionally restore files) to any earlier point |
 | Long conversation | `/compact` | Summarizes history, frees tokens |
@@ -656,6 +659,7 @@ copilot
 
 <details>
 <summary><strong>Choosing What to Reference</strong></summary>
+
 <a id="choosing-what-to-reference"></a>
 
 ### Choosing What to Reference
@@ -665,13 +669,14 @@ Not all files are equal when it comes to context. Here's how to choose wisely:
 #### File Size Considerations
 
 | File Size | Approximate [Tokens](../GLOSSARY.md#token) | Strategy |
-|-----------|-------------------|----------|
+| --- | --- | --- |
 | Small (<100 lines) | ~500-1,500 tokens | Reference freely |
 | Medium (100-500 lines) | ~1,500-7,500 tokens | Reference specific files |
 | Large (500+ lines) | 7,500+ tokens | Be selective, use specific files |
 | Very Large (1000+ lines) | 15,000+ tokens | Consider splitting or targeting sections |
 
 **Concrete examples:**
+
 - The book app's 4 Python files combined ≈ 2,000-3,000 tokens
 - A typical Python module (200 lines) ≈ 3,000 tokens
 - A Flask API file (400 lines) ≈ 6,000 tokens
@@ -683,13 +688,15 @@ Not all files are equal when it comes to context. Here's how to choose wisely:
 #### What to Include vs. Exclude
 
 **High value** (include these):
+
 - Entry points (`book_app.py`, `main.py`, `app.py`)
 - The specific files you're asking about
 - Files directly imported by your target file
 - Configuration files (`requirements.txt`, `pyproject.toml`)
 - Data models or dataclasses
 
 **Lower value** (consider excluding):
+
 - Generated files (compiled output, bundled assets)
 - Node modules or vendor directories
 - Large data files or fixtures
@@ -706,11 +713,13 @@ Less specific ──────────────────────
 ```
 
 **When to go broad** (`@samples/book-app-project/`):
+
 - Initial codebase exploration
 - Finding patterns across many files
 - Architecture reviews
 
 **When to go specific** (`@samples/book-app-project/books.py`):
+
 - Debugging a particular issue
 - Code review of a specific file
 - Asking about a single function
@@ -739,6 +748,7 @@ This staged approach keeps context focused and efficient.
 
 <details>
 <summary><strong>Working with Images</strong></summary>
+
 <a id="working-with-images"></a>
 
 ### Working with Images
@@ -847,6 +857,7 @@ The hands-on examples focused on code quality reviews and input validation. Now
 <summary>💡 Hints (click to expand)</summary>
 
 **Getting started:**
+
 ```bash
 cd /path/to/copilot-cli-for-beginners
 copilot
@@ -859,6 +870,7 @@ copilot
 Then resume with: `copilot --continue`
 
 **Useful commands:**
+
 - `@file.py` - Reference a single file
 - `@folder/` - Reference all files in a folder (note the trailing `/`)
 - `/context` - Check how much context you're using
@@ -877,12 +889,12 @@ Then resume with: `copilot --continue`
 ---
 
 <details>
-<summary>🔧 <strong>Common Mistakes & Troubleshooting</strong> (click to expand)</summary>
+<summary>🔧 <strong>Common Mistakes &amp; Troubleshooting</strong> (click to expand)</summary>
 
 ### Common Mistakes
 
 | Mistake | What Happens | Fix |
-|---------|--------------|-----|
+| --- | --- | --- |
 | Forgetting `@` before filenames | Copilot CLI treats "books.py" as plain text | Use `@samples/book-app-project/books.py` to reference files |
 | Expecting sessions to persist automatically | Starting `copilot` fresh loses all previous context | Use `--continue` (last session) or `--resume` (pick a session) |
 | Referencing files outside current directory | "Permission denied" or "File not found" errors | Use `/add-dir /path/to/directory` to grant access |
@@ -912,6 +924,7 @@ copilot --add-dir /path/to/directory
 ```
 
 **Context fills up too quickly**:
+
 - Be more specific with file references
 - Use `/clear` between different topics
 - Split work across multiple sessions
@@ -942,7 +955,7 @@ copilot --add-dir /path/to/directory
 
 Now that you can give Copilot CLI context, let's put it to work on real development tasks. The context techniques you just learned (file references, cross-file analysis, and session management) are the foundation for the powerful workflows in the next chapter.
 
-In **[Chapter 03: Development Workflows](../03-development-workflows/README.md)**, you'll learn:
+In [**Chapter 03: Development Workflows**](../03-development-workflows/README.md), you'll learn:
 
 - Code review workflows
 - Refactoring patterns
@@ -952,4 +965,4 @@ In **[Chapter 03: Development Workflows](../03-development-workflows/README.md)*
 
 ---
 
-**[← Back to Chapter 01](../01-setup-and-first-steps/README.md)** | **[Continue to Chapter 03 →](../03-development-workflows/README.md)**
+[**← Back to Chapter 01**](../01-setup-and-first-steps/README.md) | [**Continue to Chapter 03 →**](../03-development-workflows/README.md)

samples/book-app-project-cs/Services/BookCollection.cs

@@ -27,7 +27,8 @@ private void LoadBooks()
         try
         {
             var json = File.ReadAllText(_dataFile);
-            _books = JsonSerializer.Deserialize<List<Book>>(json, JsonOptions) ?? [];
+            var books = JsonSerializer.Deserialize<List<Book>>(json, JsonOptions);
+            _books = books ?? [];
         }
         catch (FileNotFoundException)
         {
@@ -42,13 +43,31 @@ private void LoadBooks()
 
     private void SaveBooks()
     {
+        var directory = Path.GetDirectoryName(_dataFile);
+        if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
+        {
+            Directory.CreateDirectory(directory);
+        }
+
         var json = JsonSerializer.Serialize(_books, JsonOptions);
         File.WriteAllText(_dataFile, json);
     }
 
     public Book AddBook(string title, string author, int year)
     {
-        var book = new Book { Title = title, Author = author, Year = year };
+        var cleanTitle = title.Trim();
+        var cleanAuthor = author.Trim();
+        if (string.IsNullOrWhiteSpace(cleanTitle) || string.IsNullOrWhiteSpace(cleanAuthor))
+        {
+            throw new ArgumentException("Title and author are required.");
+        }
+
+        if (year <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(year), "Year must be a positive integer.");
+        }
+
+        var book = new Book { Title = cleanTitle, Author = cleanAuthor, Year = year };
         _books.Add(book);
         SaveBooks();
         return book;
@@ -58,7 +77,7 @@ public Book AddBook(string title, string author, int year)
 
     public Book? FindBookByTitle(string title)
     {
-        return _books.Find(b => b.Title.Equals(title, StringComparison.OrdinalIgnoreCase));
+        return _books.Find(b => b.Title.Equals(title.Trim(), StringComparison.OrdinalIgnoreCase));
     }
 
     public bool MarkAsRead(string title)
@@ -81,8 +100,14 @@ public bool RemoveBook(string title)
 
     public List<Book> FindByAuthor(string author)
     {
+        var normalized = author.Trim();
+        if (string.IsNullOrWhiteSpace(normalized))
+        {
+            return [];
+        }
+
         return _books
-            .Where(b => b.Author.Equals(author, StringComparison.OrdinalIgnoreCase))
+            .Where(b => b.Author.Contains(normalized, StringComparison.OrdinalIgnoreCase))
             .ToList();
     }
 }

samples/book-app-project-js/books.js

@@ -13,8 +13,8 @@ class Book {
 }
 
 class BookCollection {
-  constructor(dataFile) {
-    this.dataFile = dataFile || DATA_FILE;
+  constructor(dataFile = DATA_FILE) {
+    this.dataFile = dataFile;
     this.books = [];
     this.loadBooks();
   }
@@ -23,7 +23,13 @@ class BookCollection {
     try {
       const raw = fs.readFileSync(this.dataFile, "utf-8");
       const data = JSON.parse(raw);
-      this.books = data.map((b) => new Book(b.title, b.author, b.year, b.read));
+      if (!Array.isArray(data)) {
+        this.books = [];
+        return;
+      }
+      this.books = data
+        .filter((item) => item && typeof item === "object")
+        .map((b) => new Book(b.title, b.author, b.year, !!b.read));
     } catch (err) {
       if (err.code === "ENOENT") {
         this.books = [];
@@ -37,6 +43,10 @@ class BookCollection {
   }
 
   saveBooks() {
+    const dir = path.dirname(this.dataFile);
+    if (dir && !fs.existsSync(dir)) {
+      fs.mkdirSync(dir, { recursive: true });
+    }
     const data = this.books.map((b) => ({
       title: b.title,
       author: b.author,
@@ -47,7 +57,18 @@ class BookCollection {
   }
 
   addBook(title, author, year) {
-    const book = new Book(title, author, year);
+    const cleanTitle = String(title).trim();
+    const cleanAuthor = String(author).trim();
+    if (!cleanTitle || !cleanAuthor) {
+      throw new Error("Title and author are required.");
+    }
+
+    const numericYear = Number.parseInt(year, 10);
+    if (Number.isNaN(numericYear) || numericYear <= 0) {
+      throw new Error("Year must be a positive integer.");
+    }
+
+    const book = new Book(cleanTitle, cleanAuthor, numericYear);
     this.books.push(book);
     this.saveBooks();
     return book;
@@ -58,7 +79,8 @@ class BookCollection {
   }
 
   findBookByTitle(title) {
-    return this.books.find((b) => b.title.toLowerCase() === title.toLowerCase()) || null;
+    const normalizedTitle = String(title).trim().toLowerCase();
+    return this.books.find((b) => b.title.trim().toLowerCase() === normalizedTitle) || null;
   }
 
   markAsRead(title) {
@@ -82,7 +104,11 @@ class BookCollection {
   }
 
   findByAuthor(author) {
-    return this.books.filter((b) => b.author.toLowerCase() === author.toLowerCase());
+    const normalizedAuthor = String(author).trim().toLowerCase();
+    if (!normalizedAuthor) {
+      return [];
+    }
+    return this.books.filter((b) => b.author.trim().toLowerCase().includes(normalizedAuthor));
   }
 }
 

samples/book-app-project-js/tests/test_books.js

@@ -55,4 +55,21 @@ describe("BookCollection", () => {
     const result = collection.removeBook("Nonexistent Book");
     assert.equal(result, false);
   });
+
+  it("should find books by partial author match", () => {
+    const collection = new BookCollection(tempFile);
+    collection.addBook("Dune", "Frank Herbert", 1965);
+    collection.addBook("The Hobbit", "J.R.R. Tolkien", 1937);
+
+    const matches = collection.findByAuthor("tolkien");
+
+    assert.deepEqual(matches.map((book) => book.title), ["The Hobbit"]);
+  });
+
+  it("should validate required data before adding a book", () => {
+    const collection = new BookCollection(tempFile);
+
+    assert.throws(() => collection.addBook("   ", "George Orwell", 1949), /Title and author are required/);
+    assert.throws(() => collection.addBook("1984", "George Orwell", 0), /Year must be a positive integer/);
+  });
 });