fix(bedrock-alpha): added missing validation when prompt uses default variant

packages/@aws-cdk/aws-bedrock-alpha/bedrock/prompts/prompt.ts

@@ -1,4 +1,4 @@
-import { Arn, ArnFormat, IResource, Lazy, Resource } from 'aws-cdk-lib/core';
+import { Arn, ArnFormat, IResource, Lazy, Resource, ValidationError } from 'aws-cdk-lib/core';
 import * as bedrock from 'aws-cdk-lib/aws-bedrock';
 import * as iam from 'aws-cdk-lib/aws-iam';
 import * as kms from 'aws-cdk-lib/aws-kms';
@@ -287,6 +287,7 @@ export class Prompt extends PromptBase implements IPrompt {
     // ------------------------------------------------------
     // Validation
     // ------------------------------------------------------
+    this.validatePromptDefault(props);
     this.node.addValidation({ validate: () => this.validatePromptName() });
     this.node.addValidation({ validate: () => this.validatePromptVariants() });
     this.node.addValidation({ validate: () => this.validateDescription() });
@@ -378,6 +379,16 @@ export class Prompt extends PromptBase implements IPrompt {
     return errors;
   }
 
+  /**
+   * Validates that if the prompt has a default, it was also added to the variants array
+   * @param props - The properties set in the constructor
+   */
+  private validatePromptDefault(props: PromptProps) {
+    if (props.defaultVariant && !props.variants?.includes(props.defaultVariant)) {
+      throw new ValidationError('The \'defaultVariant\' needs to be included in the \'variants\' array.', this);
+    }
+  }
+
   /**
    * Validates whether the description length is within the allowed limit.
    * @returns Array of validation error messages, empty if valid

packages/@aws-cdk/aws-bedrock-alpha/test/bedrock/prompts/prompt.test.ts

@@ -155,32 +155,32 @@ describe('Prompt', () => {
       });
     });
 
-    test('validates prompt name pattern - invalid names', () => {
-      const invalidNames = [
-        '-invalid', // starts with hyphen
-        'invalid-', // ends with hyphen
-        'a'.repeat(101), // too long
-        '', // empty
-        'invalid name', // contains space
-        'invalid@name', // contains special character
-      ];
-
-      invalidNames.forEach((name, index) => {
-        expect(() => {
-          new bedrock.Prompt(stack, `TestPrompt${index}`, {
-            promptName: name,
-          });
-        }).not.toThrow(); // Validation happens at synthesis time, not construction time
+    test.each([
+      ['-invalid', 'starts with hyphen'],
+      ['a'.repeat(101), 'too long'],
+      ['', 'empty'],
+      ['invalid name', 'contains space'],
+      ['invalid@name', 'contains special character'],
+    ])('validates prompt name pattern - %s (%s)', (invalidName, _description) => {
+      new bedrock.Prompt(stack, 'TestPrompt', {
+        promptName: invalidName,
       });
+
+      expect(() => {
+        Template.fromStack(stack);
+      }).toThrow(/Valid characters are a-z, A-Z, 0-9, _ \(underscore\) and - \(hyphen\). Must not begin with a hyphen and must be 1-100 characters long/);
     });
 
     test('validates description length', () => {
+      new bedrock.Prompt(stack, 'TestPrompt', {
+        promptName: 'test-prompt',
+        description: 'a'.repeat(251), // too long
+      });
+
+      // Validation happens at synthesis time, not construction time
       expect(() => {
-        new bedrock.Prompt(stack, 'TestPrompt', {
-          promptName: 'test-prompt',
-          description: 'a'.repeat(251), // too long
-        });
-      }).not.toThrow(); // Validation happens at synthesis time, not construction time
+        Template.fromStack(stack);
+      }).toThrow(/Description must be 200 characters or less/);
     });
 
     test('validates maximum number of variants', () => {
@@ -192,12 +192,15 @@ describe('Prompt', () => {
         }),
       );
 
+      new bedrock.Prompt(stack, 'TestPrompt', {
+        promptName: 'test-prompt',
+        variants,
+      });
+
+      // Validation happens at synthesis time, not construction time
       expect(() => {
-        new bedrock.Prompt(stack, 'TestPrompt', {
-          promptName: 'test-prompt',
-          variants,
-        });
-      }).not.toThrow(); // Validation happens at synthesis time, not construction time
+        Template.fromStack(stack);
+      }).toThrow(/Too many variants specified/);
     });
 
     test('validates unique variant names', () => {
@@ -213,12 +216,30 @@ describe('Prompt', () => {
         promptText: 'Text 2',
       });
 
+      new bedrock.Prompt(stack, 'TestPrompt', {
+        promptName: 'test-prompt',
+        variants: [variant1, variant2],
+      });
+
+      // Validation happens at synthesis time, not construction time
+      expect(() => {
+        Template.fromStack(stack);
+      }).toThrow(/Duplicate variant names found/);
+    });
+
+    test('validates default variant is added to variants array', () => {
+      const defaultVariant = bedrock.PromptVariant.text({
+        variantName: 'default-variant',
+        model: foundationModel,
+        promptText: 'Text',
+      });
+
       expect(() => {
         new bedrock.Prompt(stack, 'TestPrompt', {
-          promptName: 'test-prompt',
-          variants: [variant1, variant2],
+          promptName: 'my-test-prompt',
+          defaultVariant: defaultVariant,
         });
-      }).not.toThrow(); // Validation happens at synthesis time, not construction time
+      }).toThrow('The \'defaultVariant\' needs to be included in the \'variants\' array.');
     });
   });