Merge pull request #68 from Curabis/rule/source-organized-by-feature-not-object-type

[BCQuality] AL source organized by feature, not object type

custom/knowledge/architecture/source-organized-by-feature-not-object-type.md

@@ -0,0 +1,56 @@
+---
+bc-version: [all]
+domain: architecture
+keywords: [folder-structure, feature-organization, source-layout, maintainability]
+technologies: [al]
+countries: [w1]
+application-area: [all]
+---
+
+# AL source is organized by business feature, not by object type
+
+## Description
+
+Source folders inside an AL app should group files by the business feature
+or module they belong to (`src/Sales/Invoice/`, `src/NoSeries/`), not by
+which kind of AL object they are (`src/Tables/`, `src/Pages/`,
+`src/Codeunits/`). Object-type folders scatter everything belonging to one
+feature across half a dozen directories, so a developer picking up a
+feature has to jump between folders that share nothing but object type to
+see the whole picture. Feature folders keep a table, its pages, its
+codeunits, and its test setup physically together.
+
+Code genuinely shared across multiple features (utility codeunits,
+common interfaces, shared enums) belongs in a `Common` or `Shared` folder,
+not duplicated per feature and not left in a catch-all root.
+
+## Best Practice
+
+```
+src/
+├── NoSeries/
+├── Sales/
+│   ├── Invoice/
+│   └── Order/
+└── Common/
+```
+
+## Anti Pattern
+
+```
+src/
+├── Tables/
+├── Pages/
+└── Codeunits/
+```
+
+Finding everything related to "Sales Invoice" now requires searching three
+separate folders and mentally reassembling the feature from its scattered
+pieces.
+
+## Source
+
+alguidelines.dev, "AL Code Style & Formatting" (Microsoft-endorsed
+community guidance), cross-checked against CURABIS's own knowledge base
+(2026-08-13) — no existing rule addressed source folder layout by feature
+vs. object type; this fills that gap.