Library sample: inline produced event and author-name rejection spec

ModelFirst/Library/README.md

@@ -25,23 +25,23 @@ AddBook command
 BookAddedToCatalog event
 ```
 
-The same file contains one accepted example and one rejected example. Screenplay compiles the model; Stage runs those examples as model-level specifications.
+The same file contains one accepted example and two rejected examples: an empty title and an empty author name. Screenplay compiles the model; Stage runs those examples as model-level specifications.
 
 ```mermaid
 flowchart LR
     model[library.play] --> compiler[Screenplay compiler]
     compiler --> stage[Stage specification runner]
-    stage --> result[2 model specifications]
+    stage --> result[3 model specifications]
 ```
 
 ## What is in the model
 
 - `BookId`, `BookTitle`, and `AuthorName` concepts;
 - an `AddBook` state-change slice;
 - required title and author rules;
-- the `BookAddedToCatalog` fact;
+- the `BookAddedToCatalog` fact, declared inline with `produces event`, with typed payload mappings and the command identifier as its default event source;
 - one successful scenario;
-- one expected validation rejection.
+- two expected validation rejections.
 
 Open [`library.play`](./library.play) before running anything—the complete behavior fits on one screen.
 
@@ -67,12 +67,12 @@ dotnet run --no-build --no-restore \
 cat "$RESULTS_PATH"
 ```
 
-The current model compiles without diagnostics and produces two passing specification results.
+The current model compiles without diagnostics and produces three passing specification results.
 
 ## Make it yours
 
 - Add an ISBN concept and require it on `AddBook`.
-- Add a second rejection for an empty author name.
+- Add a specification for a book with both title and author name empty.
 - Introduce a read model after exploring the focused state-change slice.
 - Change an expected event value and watch the specification catch it.
 

ModelFirst/Library/library.play

@@ -1,7 +1,7 @@
 // Copyright (c) Cratis. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-// A deliberately small model-first sample: one command, one fact, and two model specifications.
+// A deliberately small model-first sample: one command, one inline fact, and three model specifications.
 domain Library
 
 concept BookId     : Uuid
@@ -26,14 +26,9 @@ module Library
           title not empty       message "A title is required"
           authorName not empty  message "An author name is required"
 
-        produces BookAddedToCatalog
-          for bookId
-          title      = title
-          authorName = authorName
-
-      event BookAddedToCatalog
-        title      BookTitle
-        authorName AuthorName
+        produces event BookAddedToCatalog
+          title      BookTitle  = title
+          authorName AuthorName = authorName
 
       specification AddingABook
         when AddBook
@@ -50,3 +45,10 @@ module Library
           title      = ""
           authorName = "Mara North"
         then error "A title is required"
+
+      specification RejectingABookWithoutAnAuthorName
+        when AddBook
+          bookId     = "69064f39-6a76-458a-8a34-088eb4752650"
+          title      = "The Quiet Archive"
+          authorName = ""
+        then error "An author name is required"