====== Code Quality Checklist ======

Checks for naming conventions, function design, DRY principle, and SSOT.

<note>This checklist complements the [[.:code-konventionen|Code Conventions]] with concrete verification points.</note>

===== Naming Conventions =====

==== Namespace Pattern (MS Style) ====

<code>
[ ] Unit names follow WvdS.<Category>.<Component>.pas
[ ] Mirrors Microsoft .NET structure with WvdS. prefix
[ ] Example: WvdS.UI.Controls.Button, WvdS.System.Logging
</code>

==== Class Hierarchy (Borland Style) ====

<code>
[ ] Abstract base uses TWvdSCustom* prefix
[ ] Public base uses TWvdSBase* prefix
[ ] Concrete classes use TWvdS* prefix
[ ] Pattern: TWvdSCustomXxx → TWvdSBaseXxx → TUserXxx
</code>

==== Type Prefixes ====

^ Category ^ Prefix ^ Example ^
| Classes | ''TWvdS*'' | ''TWvdSRouter'', ''TWvdSButton'' |
| Interfaces | ''IWvdS*'' | ''IWvdSActionResult'', ''IWvdSBindable'' |
| Exceptions | ''EWvdS*'' | ''EWvdSRoutingException'' |
| Records | ''TWvdS*'' | ''TWvdSBuildResult'' |
| Enums | ''TWvdS*'' | ''TWvdSProjectType'' |
| Callbacks | ''TWvdS*'' | ''TWvdSBuildCallback'' |

==== General Naming ====

<code>
[ ] Descriptive names (no single letters except loops)
[ ] No abbreviations except well-known (URL, HTTP, JSON)
[ ] Interfaces have GUID for DI container
[ ] Private fields: F* prefix (FValue, FCount)
[ ] Parameters: A* prefix (AIndex, APath)
</code>

===== Function Design =====

==== Size Guidelines ====

<code>
[ ] 12-24 lines ideal
[ ] Maximum 40 lines (split above that)
[ ] Maximum nesting depth: 3
</code>

==== Parameter Guidelines ====

<code>
[ ] Maximum 5-7 parameters
[ ] For more parameters: use record/class
[ ] Optional parameters at the end
</code>

==== Single Responsibility ====

<code>
[ ] Each function has ONE task
[ ] Function name fully describes the task
[ ] If "and" needed in name → split
</code>

==== Verb-First Naming ====

<code>
[ ] Get* - Retrieve value
[ ] Set* - Set value
[ ] Calculate* - Perform calculation
[ ] Process* - Perform processing
[ ] Validate* - Perform validation
[ ] Create* - Create object
[ ] Parse* - Parse input
[ ] Format* - Format output
</code>

===== DRY Principle =====

<code>
[ ] No duplicated code (more than 3 identical lines → extract)
[ ] No copy-paste patterns
[ ] Common logic in helper functions
[ ] Constants instead of repeated literals
</code>

==== Example: Fixing DRY Violation ====

<code pascal>
(* FORBIDDEN - Duplicated code *)
procedure ProcessUserA(const AUser: TUser);
begin
  if not ValidateEmail(AUser.Email) then
    raise EValidationError.Create('Invalid email');
  if Length(AUser.Name) > 64 then
    raise EValidationError.Create('Name too long');
  (* ... further processing *)
end;

procedure ProcessUserB(const AUser: TUser);
begin
  if not ValidateEmail(AUser.Email) then
    raise EValidationError.Create('Invalid email');
  if Length(AUser.Name) > 64 then
    raise EValidationError.Create('Name too long');
  (* ... other processing *)
end;

(* CORRECT - Common logic extracted *)
procedure ValidateUser(const AUser: TUser);
begin
  if not ValidateEmail(AUser.Email) then
    raise EValidationError.Create(rsInvalidEmail);
  if Length(AUser.Name) > MAX_NAME_LENGTH then
    raise EValidationError.Create(rsNameTooLong);
end;

procedure ProcessUserA(const AUser: TUser);
begin
  ValidateUser(AUser);
  (* ... further processing *)
end;
</code>

===== SSOT Check =====

<note warning>**Single Source of Truth** - No local copies of common code!</note>

==== Use Common Libraries ====

<code>
[ ] NodeJS APIs via ~/sources/common/web/nodejs/
    - NodeJS.FS, NodeJS.Path, NodeJS.ChildProcess
[ ] VSCode APIs via ~/sources/common/web/vscode/
    - VSCode.Window, VSCode.Commands, VSCode.Workspace
[ ] WvdS Core via ~/sources/common/core/
    - WvdS.System.Logging, WvdS.VSCode.Security
</code>

==== Forbidden ====

<code>
[ ] No direct require() calls in extensions
[ ] No duplicates of common units in extensions
[ ] No local wrapper implementations
</code>

==== Example: SSOT Violation ====

<code pascal>
(* FORBIDDEN - Local require() *)
function FileExists(const APath: string): Boolean;
begin
  asm
    var fs = require('fs');  (* SSOT violation! *)
    Result = fs.existsSync(APath);
  end;
end;

(* CORRECT - Common library *)
uses
  NodeJS.FS;

function FileExists(const APath: string): Boolean;
begin
  Result := ExistsSync(APath);  (* From NodeJS.FS *)
end;
</code>

===== Separation of Concerns =====

<code>
[ ] UI logic only in UI layer (extension_main, *Dialog)
[ ] Business logic only in service layer (*Service)
[ ] Data structures only in model layer (*Models)
[ ] Services don't call VSCode APIs directly
[ ] Models contain no logic
</code>

==== Layer Architecture ====

<code>
┌─────────────────────────────────────────────────┐
│  UI Layer (extension_main.pas, *Dialog.pas)    │
│  → VSCode APIs, User Interaction               │
├─────────────────────────────────────────────────┤
│  Service Layer (*Service.pas)                  │
│  → Business logic, Validation                  │
├─────────────────────────────────────────────────┤
│  Model Layer (*Models.pas)                     │
│  → Records, Types, Enums                       │
├─────────────────────────────────────────────────┤
│  Infrastructure (NodeJS.*, VSCode.*, WvdS.*)   │
│  → External APIs, Platform Abstraction         │
└─────────────────────────────────────────────────┘
</code>

===== Quick Checklist for Copy/Paste =====

<code>
Review Checklist (Code Quality):

Naming:
- [ ] Unit names: WvdS.<Category>.<Component>.pas
- [ ] Classes: TWvdS* prefix
- [ ] Interfaces: IWvdS* prefix
- [ ] Descriptive names (no abbreviations)

Functions:
- [ ] 12-24 lines ideal, max 40
- [ ] Max 5-7 parameters
- [ ] Single responsibility
- [ ] Verb-first naming

DRY:
- [ ] No duplicated code
- [ ] Common logic extracted
- [ ] Constants instead of literals

SSOT:
- [ ] Common libraries used
- [ ] No local require() calls
- [ ] No duplicates of common units

SoC:
- [ ] UI only in UI layer
- [ ] Logic only in service layer
- [ ] Services without direct VSCode calls
</code>

===== See also =====

  * [[.:qualitaetssicherung|Quality Assurance Overview]]
  * [[.:code-konventionen|Code Conventions]]
  * [[.:audit-core|Core Checklist]]
  * [[.:extension-entwicklung|Extension Development]]