docs: update skills guidance and book app sample coverage

.github/uvs.csv

@@ -60,3 +60,10 @@
 "05/01",738
 "05/02",529
 "05/03",571
+"05/04",1171
+"05/05",982
+"05/06",934
+"05/07",996
+"05/08",1034
+"05/09",455
+"05/10",481

.github/views.csv

@@ -59,3 +59,10 @@
 "05/01",2013
 "05/02",1317
 "05/03",1336
+"05/04",2124
+"05/05",2018
+"05/06",1906
+"05/07",2121
+"05/08",2393
+"05/09",1097
+"05/10",1003

01-setup-and-first-steps/copilot_programmatic_mode.sh

@@ -0,0 +1,5 @@
+# Review all Python files in the book app
+for file in samples/book-app-project/*.py; do
+  echo "Reviewing $file..."
+  copilot --allow-all -p "Quick code quality review of @$file - critical issues only"
+done

05-skills/README.md

@@ -101,6 +101,20 @@ While auto-triggering is the primary way skills work, you can also **invoke skil
 
 This gives you explicit control when you want to ensure a specific skill is used.
 
+#### Combining Multiple Skills in One Message
+
+You can invoke **more than one skill in a single message**, and the skill slash command can appear anywhere in your prompt — not just at the beginning. This is handy when you want two different checks done in one go:
+
+```bash
+> Check @samples/book-app-project/book_app.py with /code-checklist and also run /generate-tests for it
+
+> Review the auth module /security-audit then /code-checklist the result
+```
+
+Copilot will apply each named skill in the same response, saving you from sending multiple separate messages.
+
+> 💡 **Tip**: Put the skill slash commands wherever they feel most natural in your sentence. You can put them at the start, middle, or end of your message.
+
 > 📝 **Skills vs Agents Invocation**: Don't confuse skill invocation with agent invocation:
 > - **Skills**: `/skill-name <prompt>`, e.g., `/code-checklist Check this file`
 > - **Agents**: `/agent` (select from list) or `copilot --agent <name>` (command line)

samples/book-app-project-cs/BookApp.csproj.lscache

@@ -0,0 +1,71 @@
+version=1
+
+# This file caches language service data to improve the performance of C# Dev Kit.
+# It is not intended for manual editing. It can safely be deleted and will be
+# regenerated automatically. For more information, see https://aka.ms/lscache
+#
+# To control where cache files are stored, use the following VS Code setting:
+#   "dotnet.projectsystem.cacheInProjectFolder": true
+
+[project]
+language=C#
+primary
+lastDtbSucceeded
+
+[properties]
+AssemblyName=BookApp
+CommandLineArgsForDesignTimeEvaluation=-langversion:13.0 -define:TRACE
+CompilerGeneratedFilesOutputPath=
+MaxSupportedLangVersion=13.0
+ProjectAssetsFile=<PATH>obj/project.assets.json
+RootNamespace=BookApp
+RunAnalyzers=
+RunAnalyzersDuringLiveAnalysis=
+SolutionPath=<PATH>../../copilot-cli-for-beginners.sln
+TargetFrameworkIdentifier=.NETCoreApp
+TargetPath=<PATH>bin/Debug/net10.0/BookApp.dll
+TargetRefPath=<PATH>obj/Debug/net10.0/ref/BookApp.dll
+TemporaryDependencyNodeTargetIdentifier=net10.0
+
+[commandLineArguments]
+/noconfig
+/unsafe-
+/checked-
+/nowarn:1701,1702,1701,1702
+/fullpaths
+/nostdlib+
+/errorreport:prompt
+/warn:1
+/define:TRACE;DEBUG;NET;NET10_0;NETCOREAPP;NET5_0_OR_GREATER;NET6_0_OR_GREATER;NET7_0_OR_GREATER;NET8_0_OR_GREATER;NET9_0_OR_GREATER;NETCOREAPP1_0_OR_GREATER;NETCOREAPP1_1_OR_GREATER;NETCOREAPP2_0_OR_GREATER;NETCOREAPP2_1_OR_GREATER;NETCOREAPP2_2_OR_GREATER;NETCOREAPP3_0_OR_GREATER;NETCOREAPP3_1_OR_GREATER
+/highentropyva+
+/nullable:enable
+/debug+
+/debug:portable
+/filealign:512
+/optimize-
+/out:obj/Debug/net10.0/BookApp.dll
+/refout:obj/Debug/net10.0/refint/BookApp.dll
+/target:exe
+/warnaserror-
+/utf8output
+/deterministic+
+/langversion:13.0
+/warnaserror+:NU1605,SYSLIB0011
+
+[sourceFiles]
+Models/Book.cs
+obj/Debug/net10.0/
+ .NETCoreApp,Version=v10.0.AssemblyAttributes.cs
+ BookApp.AssemblyInfo.cs
+ BookApp.GlobalUsings.g.cs
+Program.cs
+Services/BookCollection.cs
+
+[analyzerReferences]
+../../../../../../usr/lib/dotnet/sdk/9.0.203/Sdks/Microsoft.NET.Sdk/analyzers/
+ Microsoft.CodeAnalysis.CSharp.NetAnalyzers.dll
+ Microsoft.CodeAnalysis.NetAnalyzers.dll
+
+[analyzerConfigFiles]
+../../../../../../usr/lib/dotnet/sdk/9.0.203/Sdks/Microsoft.NET.Sdk/codestyle/cs/build/config/analysislevelstyle_default.globalconfig
+obj/Debug/net10.0/BookApp.GeneratedMSBuildEditorConfig.editorconfig

samples/book-app-project-cs/Tests/BookApp.Tests.csproj.lscache

@@ -0,0 +1,72 @@
+version=1
+
+# This file caches language service data to improve the performance of C# Dev Kit.
+# It is not intended for manual editing. It can safely be deleted and will be
+# regenerated automatically. For more information, see https://aka.ms/lscache
+#
+# To control where cache files are stored, use the following VS Code setting:
+#   "dotnet.projectsystem.cacheInProjectFolder": true
+
+[project]
+language=C#
+primary
+lastDtbSucceeded
+
+[properties]
+AssemblyName=BookApp.Tests
+CommandLineArgsForDesignTimeEvaluation=-langversion:13.0 -define:TRACE
+CompilerGeneratedFilesOutputPath=
+MaxSupportedLangVersion=13.0
+ProjectAssetsFile=<PATH>obj/project.assets.json
+RootNamespace=BookApp.Tests
+RunAnalyzers=
+RunAnalyzersDuringLiveAnalysis=
+SolutionPath=<PATH>../../../copilot-cli-for-beginners.sln
+TargetFrameworkIdentifier=.NETCoreApp
+TargetPath=<PATH>bin/Debug/net10.0/BookApp.Tests.dll
+TargetRefPath=<PATH>obj/Debug/net10.0/ref/BookApp.Tests.dll
+TemporaryDependencyNodeTargetIdentifier=net10.0
+
+[commandLineArguments]
+/noconfig
+/unsafe-
+/checked-
+/nowarn:1701,1702,1701,1702
+/fullpaths
+/nostdlib+
+/errorreport:prompt
+/warn:1
+/define:TRACE;DEBUG;NET;NET10_0;NETCOREAPP;NET5_0_OR_GREATER;NET6_0_OR_GREATER;NET7_0_OR_GREATER;NET8_0_OR_GREATER;NET9_0_OR_GREATER;NETCOREAPP1_0_OR_GREATER;NETCOREAPP1_1_OR_GREATER;NETCOREAPP2_0_OR_GREATER;NETCOREAPP2_1_OR_GREATER;NETCOREAPP2_2_OR_GREATER;NETCOREAPP3_0_OR_GREATER;NETCOREAPP3_1_OR_GREATER
+/highentropyva+
+/nullable:enable
+/debug+
+/debug:portable
+/filealign:512
+/optimize-
+/out:obj/Debug/net10.0/BookApp.Tests.dll
+/refout:obj/Debug/net10.0/refint/BookApp.Tests.dll
+/target:library
+/warnaserror-
+/utf8output
+/deterministic+
+/langversion:13.0
+/warnaserror+:NU1605,SYSLIB0011
+
+[sourceFiles]
+BookCollectionTests.cs
+obj/Debug/net10.0/
+ .NETCoreApp,Version=v10.0.AssemblyAttributes.cs
+ BookApp.Tests.AssemblyInfo.cs
+ BookApp.Tests.GlobalUsings.g.cs
+
+[metadataReferences]
+../obj/Debug/net10.0/ref/BookApp.dll
+
+[analyzerReferences]
+../../../../../../../usr/lib/dotnet/sdk/9.0.203/Sdks/Microsoft.NET.Sdk/analyzers/
+ Microsoft.CodeAnalysis.CSharp.NetAnalyzers.dll
+ Microsoft.CodeAnalysis.NetAnalyzers.dll
+
+[analyzerConfigFiles]
+../../../../../../../usr/lib/dotnet/sdk/9.0.203/Sdks/Microsoft.NET.Sdk/codestyle/cs/build/config/analysislevelstyle_default.globalconfig
+obj/Debug/net10.0/BookApp.Tests.GeneratedMSBuildEditorConfig.editorconfig

samples/book-app-project/README.md

@@ -30,6 +30,7 @@ It can add, remove, and list books. Also mark them as read.
 ```bash
 python book_app.py list
 python book_app.py add
+python book_app.py mark-read
 python book_app.py find
 python book_app.py remove
 python book_app.py help

samples/book-app-project/book_app.py

@@ -1,32 +1,17 @@
 import sys
-from books import BookCollection
-
-
-# Global collection instance
-collection = BookCollection()
-
-
-def show_books(books):
-    """Display books in a user-friendly format."""
-    if not books:
-        print("No books found.")
-        return
-
-    print("\nYour Book Collection:\n")
+from collections.abc import Callable
 
-    for index, book in enumerate(books, start=1):
-        status = "✓" if book.read else " "
-        print(f"{index}. [{status}] {book.title} by {book.author} ({book.year})")
-
-    print()
+from books import BookCollection
+from utils import display_books, display_help
 
 
-def handle_list():
+def handle_list(collection: BookCollection) -> int:
     books = collection.list_books()
-    show_books(books)
+    display_books(books)
+    return 0
 
 
-def handle_add():
+def handle_add(collection: BookCollection) -> int:
     print("\nAdd a New Book\n")
 
     title = input("Title: ").strip()
@@ -37,62 +22,106 @@ def handle_add():
         year = int(year_str) if year_str else 0
         collection.add_book(title, author, year)
         print("\nBook added successfully.\n")
+        return 0
     except ValueError as e:
         print(f"\nError: {e}\n")
+        return 1
 
 
-def handle_remove():
+def handle_remove(collection: BookCollection) -> int:
     print("\nRemove a Book\n")
 
     title = input("Enter the title of the book to remove: ").strip()
-    collection.remove_book(title)
+    if not title:
+        print("\nError: Title cannot be empty.\n")
+        return 1
+
+    if collection.remove_book(title):
+        print("\nBook removed successfully.\n")
+        return 0
+
+    print("\nError: Book not found.\n")
+    return 1
+
+
+def handle_mark_read(collection: BookCollection) -> int:
+    print("\nMark a Book as Read\n")
 
-    print("\nBook removed if it existed.\n")
+    title = input("Enter the title of the book to mark as read: ").strip()
+    if not title:
+        print("\nError: Title cannot be empty.\n")
+        return 1
 
+    if collection.mark_as_read(title):
+        print("\nBook marked as read.\n")
+        return 0
 
-def handle_find():
+    print("\nError: Book not found.\n")
+    return 1
+
+
+def handle_find(collection: BookCollection) -> int:
     print("\nFind Books by Author\n")
 
     author = input("Author name: ").strip()
+    if not author:
+        print("\nError: Author cannot be empty.\n")
+        return 1
+
     books = collection.find_by_author(author)
 
-    show_books(books)
+    display_books(books)
+    return 0
+
+
+CollectionCommandHandler = Callable[[BookCollection], int]
+CommandHandler = Callable[[], int]
+
 
+def handle_help() -> int:
+    display_help()
+    return 0
 
-def show_help():
-    print("""
-Book Collection Helper
 
-Commands:
-  list     - Show all books
-  add      - Add a new book
-  remove   - Remove a book by title
-  find     - Find books by author
-  help     - Show this help message
-""")
+def create_collection_command(handler: CollectionCommandHandler) -> CommandHandler:
+    def command() -> int:
+        try:
+            collection = BookCollection()
+        except (OSError, ValueError) as e:
+            print(f"Error: {e}")
+            return 1
 
+        return handler(collection)
 
-def main():
-    if len(sys.argv) < 2:
-        show_help()
-        return
+    return command
 
-    command = sys.argv[1].lower()
 
-    if command == "list":
-        handle_list()
-    elif command == "add":
-        handle_add()
-    elif command == "remove":
-        handle_remove()
-    elif command == "find":
-        handle_find()
-    elif command == "help":
-        show_help()
-    else:
+COMMAND_HANDLERS: dict[str, CommandHandler] = {
+    "list": create_collection_command(handle_list),
+    "add": create_collection_command(handle_add),
+    "mark-read": create_collection_command(handle_mark_read),
+    "remove": create_collection_command(handle_remove),
+    "find": create_collection_command(handle_find),
+    "help": handle_help,
+}
+
+
+def main(argv: list[str] | None = None) -> int:
+    args = argv if argv is not None else sys.argv[1:]
+
+    if not args:
+        return handle_help()
+
+    command = args[0].lower()
+
+    handler = COMMAND_HANDLERS.get(command)
+    if handler is None:
         print("Unknown command.\n")
-        show_help()
+        display_help()
+        return 1
+
+    return handler()
 
 
 if __name__ == "__main__":
-    main()
+    raise SystemExit(main())