XS✔ ◾ Add Bicep User-defined Data Type Rule

categories/software-engineering/rules-to-better-azure.md

@@ -6,7 +6,7 @@ uri: rules-to-better-azure
 index:
 - choose-azure-services
 - learn-azure
-- azure-certifications-and-associated-exams 
+- azure-certifications-and-associated-exams
 - the-9-important-parts-of-azure
 - cloud-architect
 - azure-architecture-center
@@ -15,6 +15,7 @@ index:
 - do-you-always-rename-staging-url-on-azure
 - do-you-consider-azuresearch-for-your-website
 - azure-resources-creating
+- bicep-user-defined-data-types
 - azure-naming-resources
 - azure-naming-resource-groups
 - apply-tags-to-your-azure-resource-groups

rules/bicep-do-you-use-user-defined-data-types/rule.md

@@ -0,0 +1,59 @@
+---
+type: rule
+archivedreason:
+title: Bicep - Do you use User-defined Data Types?
+guid: 2a3ba816-ba40-4cfe-8193-7e151e038ac5
+uri: bicep-user-defined-data-types
+created: 2024-03-19T19:19:19.1919191Z
+authors:
+- title: Rick Su
+  url: https://ssw.com.au/people/rick-su
+related: []
+redirects: []
+
+---
+
+[User-defined data types in Bicep](https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/user-defined-data-types) allow you to create custom data structures for better code organization and type safety. They enhance reusability, abstraction, and maintainability within projects.
+
+<!--endintro-->
+
+When creating a cloud resource, numerous parameters are typically required for configuration and customization. Organizing and naming these parameters effectively is increasingly important.
+
+``` bicep
+@allowed(['Basic', 'Standard'])
+param skuName string = 'Basic'
+@allowed([5, 10, 20, 50, 100])
+param skuCapacity int = 5
+param skuSizeInGB int = 2
+```
+
+:::bad
+Bad example - Relying on parameter prefixes and order leads to unclear code, high complexity, and increased maintenance effort
+:::
+
+``` bicep
+param sku object
+```
+
+:::bad
+Bad example - When declaring a parameter as an untyped object, bicep cannot validate the object's properties and values at compile time, risking runtime errors.
+:::
+
+``` bicep
+// User-defined data type
+type skuConfig = {
+  name: 'Basic' | 'Standard'
+  capacity: 5 | 10 | 20 | 50 | 100
+  sizeInGB: int
+}
+
+param sku skuConfig = {
+  name: 'Basic'
+  capacity: 5
+  sizeInGB: 2
+}
+```
+
+:::good
+Good example - User-defined data type provides type safety, enhanced readability and making maintenance easier
+:::