chore(changelog): update unreleased changelog

- Add instructions to avoid merge conflicts in `CHANGELOG.md`
- Provide steps for using `.gitattributes` to automate conflict resolution
- Clarify recommended workflows for feature branches and merging

.gitattributes

@@ -0,0 +1 @@
+CHANGELOG.md merge=ours

.gitea/HOWTO_RELEASE.md

@@ -122,3 +122,77 @@ git commit -m "chore(version): bump to 1.2.3"
 ```
 
 > Nur die ersten beiden erscheinen im Changelog – der dritte wird **automatisch übersprungen**.
+
+---
+
+## 🧾 Umgang mit `CHANGELOG.md` beim Mergen und Releasen
+
+Wenn du automatisiert einen Changelog mit `git-cliff` erzeugst, ist `CHANGELOG.md` ein **generiertes Artefakt** – und kein handgepflegter Quelltext.
+
+Beim Mergen von Feature-Branches in `main` kann es deshalb zu **unnötigen Konflikten** in dieser Datei kommen, obwohl der Inhalt später sowieso neu erzeugt wird.
+
+---
+
+## 🧼 Umgang mit `CHANGELOG.md` in Feature-Branches
+
+Wenn du mit **Feature-Branches** arbeitest, wird `CHANGELOG.md` dort oft automatisch erzeugt.
+Das kann beim späteren Merge in `main` zu **unnötigen Merge-Konflikten** führen.
+
+### ✅ Empfohlene Vorgehensweise
+
+**Bevor du den Branch mit `main` zusammenführst** (Merge oder Cherry-Pick):
+
+```bash
+git rm CHANGELOG.md
+git commit -m "chore(changelog): remove generated CHANGELOG.md before merge"
+git push
+```
+
+Dadurch:
+
+* verhinderst du Merge-Konflikte mit `CHANGELOG.md`
+* wird die Datei bei Feature-Branches nicht mehr automatisch erzeugt
+* bleibt deine Historie sauber und konfliktfrei
+
+> 💡 Der Workflow erzeugt `CHANGELOG.md` automatisch **nur**, wenn:
+>
+> * die Datei schon vorhanden ist **oder**
+> * der Branch `main` heißt
+
+---
+
+## 🧩 Merge-Konflikte verhindern mit `.gitattributes`
+
+Damit Git bei Konflikten in `CHANGELOG.md` **automatisch deine Version bevorzugt**, kannst du folgende Zeile in die Datei `.gitattributes` aufnehmen:
+
+```gitattributes
+CHANGELOG.md merge=ours
+```
+
+Das bedeutet:
+
+* Beim Merge wird die Version aus dem aktuellen Branch (`ours`) behalten
+* Änderungen aus dem Ziel-Branch (`theirs`) werden verworfen
+
+### ✅ So verwendest du es richtig:
+
+1. **Füge die Regel in `main` hinzu**:
+
+```bash
+echo "CHANGELOG.md merge=ours" >> .gitattributes
+git add .gitattributes
+git commit -m "chore(git): prevent merge conflicts in CHANGELOG.md"
+git push origin main
+```
+
+2. **Hole sie in deinen Feature-Branch**:
+
+```bash
+git checkout feature/xyz
+git rebase origin/main
+```
+
+3. **Ab sofort werden Konflikte in `CHANGELOG.md` automatisch aufgelöst** – lokal.
+
+> ⚠️ Hinweis: Plattformen wie **Gitea, GitHub oder GitLab ignorieren `.gitattributes` beim Merge über die Web-Oberfläche**.
+> Führe Merges daher **lokal** durch, wenn du Konflikte verhindern willst.

.gitea/workflows/release.yml

@@ -4,38 +4,44 @@ on:
   push:
     branches:
       - main
+      - '**'
 
 jobs:
   detect-version-change:
     runs-on: ubuntu-latest
     outputs:
-      version_changed: ${{ steps.check.outputs.version_changed }}
+      version_changed: ${{ steps.set.outputs.version_changed }}
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Check if VERSION file changed
-        id: check
+        if: github.ref == 'refs/heads/main'
         run: |
           echo "🔍 Vergleich mit github.event.before:"
           echo "Before: ${{ github.event.before }}"
           echo "After:  ${{ github.sha }}"
-          
+
           echo "📄 Changed files between before and after:"
           git diff --name-only ${{ github.event.before }} ${{ github.sha }} || echo "(diff failed)"
 
           if git diff --name-only ${{ github.event.before }} ${{ github.sha }} | grep -q '^VERSION$'; then
-            echo "✅ VERSION file was changed between before and after"
-            echo "version_changed=true" >> $GITHUB_OUTPUT
+            echo "✅ VERSION file was changed"
+            echo "VERSION_CHANGED=true" >> $GITHUB_ENV
           else
-            echo "ℹ️ VERSION file not changed between before and after"
-            echo "version_changed=false" >> $GITHUB_OUTPUT
+            echo "ℹ️ VERSION file not changed"
+            echo "VERSION_CHANGED=false" >> $GITHUB_ENV
           fi
 
+      - name: Set output (always)
+        id: set
+        run: |
+          echo "version_changed=${VERSION_CHANGED:-false}" >> $GITHUB_OUTPUT
+
   changelog-only:
     needs: detect-version-change
-    if: needs.detect-version-change.outputs.version_changed == 'false'
+    if: github.ref != 'refs/heads/main' || needs.detect-version-change.outputs.version_changed == 'false'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -65,8 +71,14 @@ jobs:
         run: |
           cargo install git-cliff --version "${{ steps.cliff_version.outputs.version }}" --features gitea
 
-      - name: Generate unreleased changelog
-        run: git-cliff -c cliff.toml -o CHANGELOG.md
+      - name: Generate unreleased changelog (if file exists or on main)
+        run: |
+          if [[ -f CHANGELOG.md || "${GITHUB_REF##refs/heads/}" == "main" ]]; then
+            echo "Generating CHANGELOG.md..."
+            git-cliff -c cliff.toml -o CHANGELOG.md
+          else
+            echo "CHANGELOG.md does not exist and this is not 'main'. Skipping generation."
+          fi
 
       - name: Commit updated CHANGELOG
         run: |
@@ -75,12 +87,12 @@ jobs:
             echo "No changes to commit"
           else
             git commit -m "chore(changelog): update unreleased changelog"
-            git push origin main
+            git push origin "${GITHUB_REF##refs/heads/}"
           fi
 
   release:
     needs: detect-version-change
-    if: needs.detect-version-change.outputs.version_changed == 'true'
+    if: needs.detect-version-change.outputs.version_changed == 'true' && github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

CHANGELOG.md

@@ -6,19 +6,30 @@ All notable changes to this project will be documented in this file.
 
 ### 🚀 Features
 
+- *(workflows)* Conditionally generate changelog - ([2ab6f1b](https://git.0xmax42.io/maxp/http-kernel/commit/2ab6f1b8db2d7bd31ca30248d0de183f17a5738c))
+- *(interfaces)* Add pipeline executor interface - ([927a908](https://git.0xmax42.io/maxp/http-kernel/commit/927a9081d4f363202520d017eb424c7c097ced94))
+- *(pipeline)* Add configuration and hooks for pipeline execution - ([3f114bb](https://git.0xmax42.io/maxp/http-kernel/commit/3f114bb68d94c48a53514752d57cb4f01adeaae3))
 - *(workflows)* Add CI for Deno project tests - ([9d5db4f](https://git.0xmax42.io/maxp/http-kernel/commit/9d5db4f414cf961248f2b879f2b132b81a32cb92))
 
+### 🐛 Bug Fixes
+
+- *(workflows)* Ensure version detection output is always set - ([abd2d6e](https://git.0xmax42.io/maxp/http-kernel/commit/abd2d6e8402662f863d9974aaa0bc228a4777724))
+
 ### 🚜 Refactor
 
 - *(workflows)* Rename changelog file for consistency - ([b9d25f2](https://git.0xmax42.io/maxp/http-kernel/commit/b9d25f23fc6ad7696deee319024aa5b1af4d98c0))
 
 ### 📚 Documentation
 
+- *(release)* Update guidelines for handling changelog - ([6ce73c1](https://git.0xmax42.io/maxp/http-kernel/commit/6ce73c14fa6736b622e646feb61522e6ec1f4c5a))
+- *(pipeline)* Add design plan for PipelineExecutor class - ([0846dbb](https://git.0xmax42.io/maxp/http-kernel/commit/0846dbb758ba788f969a381c56498920ee0f9562))
 - Add README for HttpKernel project - ([a1ce306](https://git.0xmax42.io/maxp/http-kernel/commit/a1ce30627c68a3f869eb6a104308322af8596dc1))
 - Add MIT license file - ([5118a19](https://git.0xmax42.io/maxp/http-kernel/commit/5118a19aeaa1102591aa7fe093fdec1aa19dc7f5))
 
 ### ⚙️ Miscellaneous Tasks
 
+- *(git)* Ignore merge conflicts for CHANGELOG.md - ([d04dfcd](https://git.0xmax42.io/maxp/http-kernel/commit/d04dfcd63ea2478ffdff2e966d310194dafd8d7d))
+- *(workflows)* Refine branch handling in release process - ([8f94cc9](https://git.0xmax42.io/maxp/http-kernel/commit/8f94cc915c75a11efa1a8e3bdc51ffea9c2f19b5))
 - *(workflows)* Update changelog file extension to .md and revert b9d25f23fc - ([a88b4d1](https://git.0xmax42.io/maxp/http-kernel/commit/a88b4d112f5c07664d41f6e9d03246307551f25d))
 - Rename changelog and readme files to use .md extension - ([4f2b650](https://git.0xmax42.io/maxp/http-kernel/commit/4f2b65049f461ef377e7231905fd066cbc3c7fe0))
 - *(workflows)* Update test workflow for http-kernel project - ([0311546](https://git.0xmax42.io/maxp/http-kernel/commit/03115464e0fb01b8ca00a2fdabde013d004ae8a2))

docs/pipeline_executor_plan.md

@@ -0,0 +1,72 @@
+# 🧩 Plan: `PipelineExecutor<TContext>`
+
+## 🎯 Ziel
+Eine eigenständige, testbare Klasse zur Ausführung einer Middleware- und Handler-Pipeline, die:
+- Linear und sauber das `next()`-Verhalten abbildet
+- Typvalidierung durchführt (`isMiddleware`, `isHandler`)
+- Fehler behandelt und an konfigurierbare Handler weiterleitet
+- Optionale Hooks zur Tracing-Integration bietet (z. B. für Zeitmessung, Logging)
+- Am Ende eine dekorierte `Response` zurückliefert
+
+---
+
+## 🧩 Schnittstelle (API)
+
+```ts
+class PipelineExecutor<TContext extends IContext> {
+    constructor(cfg: IHttpKernelConfig<TContext>);
+
+    run(
+        ctx: TContext,
+        middleware: Middleware<TContext>[],
+        handler: Handler<TContext>,
+        hooks?: IPipelineHooks<TContext>, // optional
+    ): Promise<Response>;
+}
+```
+
+---
+
+## 🪝 Hook-Schnittstelle (`IPipelineHooks`)
+
+```ts
+interface IPipelineHooks<TContext> {
+    onPipelineStart?(ctx: TContext): void;
+    onStepStart?(name: string | undefined, ctx: TContext): void;
+    onStepEnd?(name: string | undefined, ctx: TContext, duration: number): void;
+    onPipelineEnd?(ctx: TContext, totalDuration: number): void;
+}
+```
+
+- `name` ist `undefined`, wenn keine `.name` am Handler/Middleware gesetzt ist
+- Diese Hooks ermöglichen später Logging, Zeitmessung, Statistiken etc.
+- Der `TraceManager` wird dieses Interface implementieren
+
+---
+
+## 🛠️ Interne Aufgaben / Ablauf
+
+1. `run(...)` beginnt mit Aufruf `onPipelineStart(ctx)`
+2. Zeitmessung (`performance.now()`)
+3. Dispatcher-Funktion führt jede Middleware mit `next()`-Kette aus
+4. Vor jedem Aufruf: `onStepStart(name, ctx)`
+5. Nach jedem Aufruf: `onStepEnd(name, ctx, duration)`
+6. Nach letztem Handler: `onPipelineEnd(ctx, totalDuration)`
+7. Ergebnis wird durch `cfg.decorateResponse(res, ctx)` geschickt
+8. Im Fehlerfall: `cfg.httpErrorHandlers[500](ctx, error)`
+
+---
+
+## ✅ Vorteile
+
+- `HttpKernel` ist von Ausführungsdetails entkoppelt
+- Tracing-/Logging-System kann ohne Invasivität angeschlossen werden
+- Sehr gut testbar (z. B. Middleware-Mock + Hook-Aufrufe prüfen)
+- Erweiterbar für Timeout, Async-Context, Abbruchlogik etc.
+
+---
+
+## 📦 Dateiname-Vorschlag
+
+- `src/Core/PipelineExecutor.ts` oder
+- `src/HttpKernel/PipelineExecutor.ts`

src/Interfaces/IPipelineExecutor.ts

@@ -0,0 +1,50 @@
+import { Handler, Middleware } from '../Types/mod.ts';
+import { IContext } from './IContext.ts';
+import { IPipelineExecutorConfig } from './IPipelineExecutorConfig.ts';
+
+/**
+ * Constructor type for a class implementing the IPipelineExecutor interface.
+ *
+ * This can be used for dependency injection, factory-based initialization,
+ * or dynamic instantiation of pipeline executors.
+ *
+ * @template TContext - The extended context type passed through the pipeline.
+ */
+export interface PipelineExecutorFactory<TContext extends IContext = IContext> {
+    /**
+     * Creates a new instance of a pipeline executor.
+     *
+     * @param config - Configuration used to control error handling,
+     *                 response decoration and lifecycle hooks.
+     */
+    new (
+        config: IPipelineExecutorConfig<TContext>,
+    ): IPipelineExecutor<TContext>;
+}
+
+/**
+ * Defines the contract for executing a middleware and handler pipeline.
+ *
+ * The pipeline is responsible for:
+ * - Executing middleware in order with `next()` chaining
+ * - Invoking the final handler
+ * - Applying optional lifecycle hooks
+ * - Producing and decorating a Response
+ *
+ * @template TContext - The context type flowing through the pipeline.
+ */
+export interface IPipelineExecutor<TContext extends IContext = IContext> {
+    /**
+     * Executes the middleware pipeline and returns the final Response.
+     *
+     * @param ctx - The context object representing the current HTTP request state.
+     * @param middleware - An ordered array of middleware functions to be executed.
+     * @param handler - The final route handler to be called after all middleware.
+     * @returns A Promise resolving to the final HTTP Response.
+     */
+    run(
+        ctx: TContext,
+        middleware: Middleware<TContext>[],
+        handler: Handler<TContext>,
+    ): Promise<Response>;
+}

src/Interfaces/IPipelineExecutorConfig.ts

@@ -0,0 +1,33 @@
+import { ResponseDecorator } from '../Types/ResponseDecorator.ts';
+import { IContext } from './IContext.ts';
+import { IHttpErrorHandlers } from './IHttpErrorHandlers.ts';
+import { IPipelineHooks } from './IPipelineHooks.ts';
+
+/**
+ * Configuration object for the PipelineExecutor, defining how to handle
+ * errors, responses, and tracing hooks.
+ *
+ * This allows the execution logic to remain decoupled from kernel-level behavior
+ * while still supporting custom behavior injection.
+ *
+ * @template TContext - The context type propagated during pipeline execution.
+ */
+export interface IPipelineExecutorConfig<TContext extends IContext = IContext> {
+    /**
+     * Optional function used to transform or decorate the final Response object
+     * before it is returned to the client.
+     */
+    decorateResponse?: ResponseDecorator<TContext>;
+
+    /**
+     * Optional map of error handlers, keyed by HTTP status codes (e.g., 404, 500).
+     * These handlers are invoked if an error occurs during middleware or handler execution.
+     */
+    errorHandlers?: IHttpErrorHandlers<TContext>;
+
+    /**
+     * Optional hooks that allow tracing and lifecycle monitoring during pipeline execution.
+     * Each hook is called at a specific phase of the middleware/handler lifecycle.
+     */
+    pipelineHooks?: IPipelineHooks<TContext>;
+}

src/Interfaces/IPipelineHooks.ts

@@ -0,0 +1,36 @@
+import {
+    OnPipelineEnd,
+    OnPipelineStart,
+    OnStepEnd,
+    OnStepStart,
+} from '../Types/mod.ts';
+import { IContext } from './IContext.ts';
+
+/**
+ * A set of optional hook functions that can be triggered during pipeline execution.
+ * These hooks allow tracing, performance measurement, and logging to be integrated
+ * without altering middleware or handler logic.
+ *
+ * @template TContext - The custom context type used within the application.
+ */
+export interface IPipelineHooks<TContext extends IContext = IContext> {
+    /**
+     * Triggered once before any middleware or handler is executed.
+     */
+    onPipelineStart?: OnPipelineStart<TContext>;
+
+    /**
+     * Triggered immediately before each middleware or handler runs.
+     */
+    onStepStart?: OnStepStart<TContext>;
+
+    /**
+     * Triggered immediately after each middleware or handler has finished executing.
+     */
+    onStepEnd?: OnStepEnd<TContext>;
+
+    /**
+     * Triggered after the entire pipeline completes execution.
+     */
+    onPipelineEnd?: OnPipelineEnd<TContext>;
+}

src/Interfaces/mod.ts

@@ -5,6 +5,12 @@ export type { IHttpErrorHandlers } from './IHttpErrorHandlers.ts';
 export type { IHttpKernel } from './IHttpKernel.ts';
 export type { IHttpKernelConfig } from './IHttpKernelConfig.ts';
 export type { IInternalRoute } from './IInternalRoute.ts';
+export type {
+    IPipelineExecutor,
+    PipelineExecutorFactory,
+} from './IPipelineExecutor.ts';
+export type { IPipelineExecutorConfig } from './IPipelineExecutorConfig.ts';
+export type { IPipelineHooks } from './IPipelineHooks.ts';
 export type { IRouteBuilder, IRouteBuilderFactory } from './IRouteBuilder.ts';
 export {
     isDynamicRouteDefinition,

src/Types/PipelineHooks.ts

@@ -0,0 +1,49 @@
+import { IContext } from '../Interfaces/mod.ts';
+
+/**
+ * A callback invoked when the middleware pipeline starts.
+ *
+ * @template TContext - The context type passed throughout the pipeline.
+ * @param ctx - The context object for the current request.
+ */
+export type OnPipelineStart<TContext extends IContext> = (
+    ctx: TContext,
+) => void;
+
+/**
+ * A callback invoked immediately before a middleware or handler is executed.
+ *
+ * @template TContext - The context type passed throughout the pipeline.
+ * @param name - Optional name of the current middleware or handler, if defined.
+ * @param ctx - The context object for the current request.
+ */
+export type OnStepStart<TContext extends IContext> = (
+    name: string | undefined,
+    ctx: TContext,
+) => void;
+
+/**
+ * A callback invoked immediately after a middleware or handler has completed.
+ *
+ * @template TContext - The context type passed throughout the pipeline.
+ * @param name - Optional name of the current middleware or handler, if defined.
+ * @param ctx - The context object for the current request.
+ * @param duration - Execution time in milliseconds.
+ */
+export type OnStepEnd<TContext extends IContext> = (
+    name: string | undefined,
+    ctx: TContext,
+    duration: number,
+) => void;
+
+/**
+ * A callback invoked after the entire pipeline has completed execution.
+ *
+ * @template TContext - The context type passed throughout the pipeline.
+ * @param ctx - The context object for the current request.
+ * @param totalDuration - Total execution time of the pipeline in milliseconds.
+ */
+export type OnPipelineEnd<TContext extends IContext> = (
+    ctx: TContext,
+    totalDuration: number,
+) => void;

src/Types/mod.ts

@@ -39,6 +39,12 @@ export type { HttpStatusCode } from './HttpStatusCode.ts';
 export { isMiddleware } from './Middleware.ts';
 export type { Middleware } from './Middleware.ts';
 export type { Params } from './Params.ts';
+export type {
+    OnPipelineEnd,
+    OnPipelineStart,
+    OnStepEnd,
+    OnStepStart,
+} from './PipelineHooks.ts';
 export type { Query } from './Query.ts';
 export type { RegisterRoute } from './RegisterRoute.ts';
 export type { ResponseDecorator } from './ResponseDecorator.ts';