Preisrechner: Rappenrundung im Backend und Rabatt-Rechner im Web

agentd task d23b198e9bef4e0c99f52c532c317f70

src/Prices/PriceCalculator.cs

@@ -16,6 +16,7 @@ public static class PriceCalculator
             throw new ArgumentOutOfRangeException(nameof(discountPercent), "A discount is between 0 and 100 percent.");
         }
 
-        return price * (100m - discountPercent) / 100m;
+        var raw = price * (100 - discountPercent) / 100;
+        return Math.Round(raw / 0.05m, MidpointRounding.AwayFromZero) * 0.05m;
     }
-}
+}

tests/Prices.Tests/PriceCalculatorTests.cs

@@ -33,4 +33,31 @@ public sealed class PriceCalculatorTests
     {
         Assert.Throws<ArgumentOutOfRangeException>(() => PriceCalculator.ApplyDiscount(100m, 101m));
     }
-}
+
+    [Fact]
+    public void Swiss_rounding_example()
+    {
+        // 99.90 * 90 / 100 = 89.91, gerundet auf 0.05 = 89.90
+        Assert.Equal(89.90m, PriceCalculator.ApplyDiscount(99.90m, 10m));
+    }
+
+    [Fact]
+    public void Swiss_rounding_exact()
+    {
+        // 100.00 * 85 / 100 = 85.00, exakt ein 0.05-Vielfaches
+        Assert.Equal(85.00m, PriceCalculator.ApplyDiscount(100.00m, 15m));
+    }
+
+    [Fact]
+    public void Swiss_rounding_midpoint_up()
+    {
+        // 10.00 * 95 / 100 = 9.50, exakt
+        Assert.Equal(9.50m, PriceCalculator.ApplyDiscount(10.00m, 5m));
+    }
+
+    [Fact]
+    public void Negative_price_throws()
+    {
+        Assert.Throws<ArgumentOutOfRangeException>(() => PriceCalculator.ApplyDiscount(-1m, 10m));
+    }
+}

web/.editorconfig

@@ -0,0 +1,17 @@
+# Editor configuration, see https://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.ts]
+quote_type = single
+ij_typescript_use_double_quotes = false
+
+[*.md]
+max_line_length = off
+trim_trailing_whitespace = false

web/.gitignore

@@ -0,0 +1,44 @@
+# See https://docs.github.com/get-started/getting-started-with-git/ignoring-files for more about ignoring files.
+
+# Compiled output
+/dist
+/tmp
+/out-tsc
+/bazel-out
+
+# Node
+/node_modules
+npm-debug.log
+yarn-error.log
+
+# IDEs and editors
+.idea/
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# Visual Studio Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+!.vscode/mcp.json
+.history/*
+
+# Miscellaneous
+/.angular/cache
+.sass-cache/
+/connect.lock
+/coverage
+/libpeerconnection.log
+testem.log
+/typings
+__screenshots__/
+
+# System files
+.DS_Store
+Thumbs.db

web/.prettierrc

@@ -0,0 +1,12 @@
+{
+  "printWidth": 100,
+  "singleQuote": true,
+  "overrides": [
+    {
+      "files": "*.html",
+      "options": {
+        "parser": "angular"
+      }
+    }
+  ]
+}

web/.vscode/extensions.json

@@ -0,0 +1,4 @@
+{
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=827846
+  "recommendations": ["angular.ng-template"]
+}

web/.vscode/launch.json

@@ -0,0 +1,20 @@
+{
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "ng serve",
+      "type": "chrome",
+      "request": "launch",
+      "preLaunchTask": "npm: start",
+      "url": "http://localhost:4200/"
+    },
+    {
+      "name": "ng test",
+      "type": "chrome",
+      "request": "launch",
+      "preLaunchTask": "npm: test",
+      "url": "http://localhost:9876/debug.html"
+    }
+  ]
+}

web/.vscode/tasks.json

@@ -0,0 +1,42 @@
+{
+  // For more information, visit: https://go.microsoft.com/fwlink/?LinkId=733558
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "start",
+      "isBackground": true,
+      "problemMatcher": {
+        "owner": "typescript",
+        "pattern": "$tsc",
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": {
+            "regexp": "Changes detected"
+          },
+          "endsPattern": {
+            "regexp": "bundle generation (complete|failed)"
+          }
+        }
+      }
+    },
+    {
+      "type": "npm",
+      "script": "test",
+      "isBackground": true,
+      "problemMatcher": {
+        "owner": "typescript",
+        "pattern": "$tsc",
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": {
+            "regexp": "Changes detected"
+          },
+          "endsPattern": {
+            "regexp": "bundle generation (complete|failed)"
+          }
+        }
+      }
+    }
+  ]
+}

web/README.md

@@ -0,0 +1,59 @@
+# Web
+
+This project was generated using [Angular CLI](https://github.com/angular/angular-cli) version 22.1.2.
+
+## Development server
+
+To start a local development server, run:
+
+```bash
+ng serve
+```
+
+Once the server is running, open your browser and navigate to `http://localhost:4200/`. The application will automatically reload whenever you modify any of the source files.
+
+## Code scaffolding
+
+Angular CLI includes powerful code scaffolding tools. To generate a new component, run:
+
+```bash
+ng generate component component-name
+```
+
+For a complete list of available schematics (such as `components`, `directives`, or `pipes`), run:
+
+```bash
+ng generate --help
+```
+
+## Building
+
+To build the project run:
+
+```bash
+ng build
+```
+
+This will compile your project and store the build artifacts in the `dist/` directory. By default, the production build optimizes your application for performance and speed.
+
+## Running unit tests
+
+To execute unit tests with the [Vitest](https://vitest.dev/) test runner, use the following command:
+
+```bash
+ng test
+```
+
+## Running end-to-end tests
+
+For end-to-end (e2e) testing, run:
+
+```bash
+ng e2e
+```
+
+Angular CLI does not come with an end-to-end testing framework by default. You can choose one that suits your needs.
+
+## Additional Resources
+
+For more information on using the Angular CLI, including detailed command references, visit the [Angular CLI Overview and Command Reference](https://angular.dev/tools/cli) page.

web/angular.json

@@ -0,0 +1,78 @@
+{
+  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
+  "version": 1,
+  "cli": {
+    "packageManager": "npm"
+  },
+  "newProjectRoot": "projects",
+  "projects": {
+    "web": {
+      "projectType": "application",
+      "schematics": {
+        "@schematics/angular:component": {
+          "style": "scss"
+        }
+      },
+      "root": "",
+      "sourceRoot": "src",
+      "prefix": "app",
+      "architect": {
+        "build": {
+          "builder": "@angular/build:application",
+          "options": {
+            "browser": "src/main.ts",
+            "tsConfig": "tsconfig.app.json",
+            "inlineStyleLanguage": "scss",
+            "assets": [
+              {
+                "glob": "**/*",
+                "input": "public"
+              }
+            ],
+            "styles": [
+              "src/styles.scss"
+            ]
+          },
+          "configurations": {
+            "production": {
+              "budgets": [
+                {
+                  "type": "initial",
+                  "maximumWarning": "500kB",
+                  "maximumError": "1MB"
+                },
+                {
+                  "type": "anyComponentStyle",
+                  "maximumWarning": "4kB",
+                  "maximumError": "8kB"
+                }
+              ],
+              "outputHashing": "all"
+            },
+            "development": {
+              "optimization": false,
+              "extractLicenses": false,
+              "sourceMap": true
+            }
+          },
+          "defaultConfiguration": "production"
+        },
+        "serve": {
+          "builder": "@angular/build:dev-server",
+          "configurations": {
+            "production": {
+              "buildTarget": "web:build:production"
+            },
+            "development": {
+              "buildTarget": "web:build:development"
+            }
+          },
+          "defaultConfiguration": "development"
+        },
+        "test": {
+          "builder": "@angular/build:unit-test"
+        }
+      }
+    }
+  }
+}

web/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "web",
+  "version": "0.0.0",
+  "scripts": {
+    "ng": "ng",
+    "start": "ng serve",
+    "build": "ng build",
+    "watch": "ng build --watch --configuration development",
+    "test": "ng test"
+  },
+  "private": true,
+  "packageManager": "npm@10.8.3",
+  "dependencies": {
+    "@angular/common": "^22.1.0",
+    "@angular/compiler": "^22.1.0",
+    "@angular/core": "^22.1.0",
+    "@angular/forms": "^22.1.0",
+    "@angular/platform-browser": "^22.1.0",
+    "@angular/router": "^22.1.0",
+    "rxjs": "~7.8.0",
+    "tslib": "^2.3.0"
+  },
+  "devDependencies": {
+    "@angular/build": "^22.1.2",
+    "@angular/cli": "^22.1.2",
+    "@angular/compiler-cli": "^22.1.0",
+    "jsdom": "^28.0.0",
+    "prettier": "^3.8.1",
+    "typescript": "~6.0.2",
+    "vitest": "^4.0.8"
+  }
+}

web/src/app/app.config.ts

@@ -0,0 +1,11 @@
+import { ApplicationConfig, provideBrowserGlobalErrorListeners } from '@angular/core';
+import { provideRouter } from '@angular/router';
+
+import { routes } from './app.routes';
+
+export const appConfig: ApplicationConfig = {
+  providers: [
+    provideBrowserGlobalErrorListeners(),
+    provideRouter(routes)
+  ]
+};

web/src/app/app.html

@@ -0,0 +1,3 @@
+<main class="main">
+  <router-outlet />
+</main>

web/src/app/app.routes.ts

@@ -0,0 +1,9 @@
+import { Routes } from '@angular/router';
+import { DiscountCalculator } from './discount-calculator/discount-calculator';
+
+export const routes: Routes = [
+  {
+    path: '',
+    component: DiscountCalculator,
+  },
+];

web/src/app/app.spec.ts

@@ -0,0 +1,26 @@
+import { TestBed } from '@angular/core/testing';
+import { App } from './app';
+import { provideRouter } from '@angular/router';
+import { routes } from './app.routes';
+
+describe('App', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [App],
+      providers: [provideRouter(routes)],
+    }).compileComponents();
+  });
+
+  it('should create the app', () => {
+    const fixture = TestBed.createComponent(App);
+    const app = fixture.componentInstance;
+    expect(app).toBeTruthy();
+  });
+
+  it('should render the router outlet', async () => {
+    const fixture = TestBed.createComponent(App);
+    await fixture.whenStable();
+    const compiled = fixture.nativeElement as HTMLElement;
+    expect(compiled.querySelector('router-outlet')).toBeTruthy();
+  });
+});

web/src/app/app.ts

@@ -0,0 +1,12 @@
+import { Component, signal } from '@angular/core';
+import { RouterOutlet } from '@angular/router';
+
+@Component({
+  selector: 'app-root',
+  imports: [RouterOutlet],
+  templateUrl: './app.html',
+  styleUrl: './app.scss'
+})
+export class App {
+  protected readonly title = signal('web');
+}

web/src/app/discount-calculator/discount-calculator.html

@@ -0,0 +1,39 @@
+<div class="calculator">
+  <h2>Rabattrechner</h2>
+
+  <div class="field">
+    <label for="price">Preis (CHF):</label>
+    <input
+      id="price"
+      type="number"
+      step="0.01"
+      min="0"
+      [value]="price()"
+      (input)="onPriceInput($event)"
+      placeholder="z. B. 99.90"
+    />
+  </div>
+
+  <div class="field">
+    <label for="discount">Rabatt (%):</label>
+    <input
+      id="discount"
+      type="number"
+      step="0.1"
+      min="0"
+      max="100"
+      [value]="discountPercent()"
+      (input)="onDiscountInput($event)"
+      placeholder="z. B. 10"
+    />
+  </div>
+
+  <button (click)="calculate()" class="btn">Berechnen</button>
+
+  @if (result() !== null) {
+    <div class="result">
+      <span class="result-label">Reduzierter Preis:</span>
+      <span class="result-value">{{ result()!.toFixed(2) }} CHF</span>
+    </div>
+  }
+</div>

web/src/app/discount-calculator/discount-calculator.scss

@@ -0,0 +1,79 @@
+.calculator {
+  max-width: 400px;
+  margin: 2rem auto;
+  padding: 2rem;
+  border: 1px solid #ddd;
+  border-radius: 8px;
+  background: #fafafa;
+
+  h2 {
+    margin-top: 0;
+    margin-bottom: 1.5rem;
+    font-size: 1.5rem;
+    color: #333;
+  }
+
+  .field {
+    margin-bottom: 1rem;
+
+    label {
+      display: block;
+      margin-bottom: 0.25rem;
+      font-weight: 500;
+      color: #555;
+    }
+
+    input {
+      width: 100%;
+      padding: 0.5rem;
+      border: 1px solid #ccc;
+      border-radius: 4px;
+      font-size: 1rem;
+      box-sizing: border-box;
+
+      &:focus {
+        outline: none;
+        border-color: #007bff;
+        box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
+      }
+    }
+  }
+
+  .btn {
+    display: inline-block;
+    padding: 0.5rem 1.5rem;
+    font-size: 1rem;
+    color: #fff;
+    background: #007bff;
+    border: none;
+    border-radius: 4px;
+    cursor: pointer;
+    margin-top: 0.5rem;
+
+    &:hover {
+      background: #0056b3;
+    }
+  }
+
+  .result {
+    margin-top: 1.5rem;
+    padding: 1rem;
+    background: #e8f5e9;
+    border: 1px solid #c8e6c9;
+    border-radius: 4px;
+    text-align: center;
+
+    .result-label {
+      display: block;
+      font-size: 0.9rem;
+      color: #555;
+      margin-bottom: 0.25rem;
+    }
+
+    .result-value {
+      font-size: 1.75rem;
+      font-weight: 700;
+      color: #2e7d32;
+    }
+  }
+}

web/src/app/discount-calculator/discount-calculator.spec.ts

@@ -0,0 +1,44 @@
+import { TestBed } from '@angular/core/testing';
+import { DiscountCalculator } from './discount-calculator';
+
+describe('DiscountCalculator', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [DiscountCalculator],
+    }).compileComponents();
+  });
+
+  it('should create the component', () => {
+    const fixture = TestBed.createComponent(DiscountCalculator);
+    const component = fixture.componentInstance;
+    expect(component).toBeTruthy();
+  });
+
+  it('should calculate 89.90 for price 99.90 and discount 10%', () => {
+    const fixture = TestBed.createComponent(DiscountCalculator);
+    const component = fixture.componentInstance;
+    component.price.set(99.90);
+    component.discountPercent.set(10);
+    component.calculate();
+    expect(component.result()).toBeCloseTo(89.90, 2);
+  });
+
+  it('should round to nearest 0.05 (Swiss Rappenrundung)', () => {
+    const fixture = TestBed.createComponent(DiscountCalculator);
+    const component = fixture.componentInstance;
+    component.price.set(10);
+    component.discountPercent.set(2.5);
+    component.calculate();
+    // 10 * (100 - 2.5) / 100 = 9.75 → rounded to 0.05 → 9.75
+    expect(component.result()).toBeCloseTo(9.75, 2);
+  });
+
+  it('should handle zero price', () => {
+    const fixture = TestBed.createComponent(DiscountCalculator);
+    const component = fixture.componentInstance;
+    component.price.set(0);
+    component.discountPercent.set(50);
+    component.calculate();
+    expect(component.result()).toBeCloseTo(0, 2);
+  });
+});

web/src/app/discount-calculator/discount-calculator.ts

@@ -0,0 +1,30 @@
+import { Component, signal } from '@angular/core';
+
+@Component({
+  selector: 'app-discount-calculator',
+  templateUrl: './discount-calculator.html',
+  styleUrl: './discount-calculator.scss',
+})
+export class DiscountCalculator {
+  readonly price = signal<number>(0);
+  readonly discountPercent = signal<number>(0);
+  readonly result = signal<number | null>(null);
+
+  onPriceInput(event: Event): void {
+    const input = event.target as HTMLInputElement;
+    this.price.set(parseFloat(input.value) || 0);
+    this.result.set(null);
+  }
+
+  onDiscountInput(event: Event): void {
+    const input = event.target as HTMLInputElement;
+    this.discountPercent.set(parseFloat(input.value) || 0);
+    this.result.set(null);
+  }
+
+  calculate(): void {
+    const discountedPrice = this.price() * (100 - this.discountPercent()) / 100;
+    const rounded = Math.round(discountedPrice / 0.05) * 0.05;
+    this.result.set(rounded);
+  }
+}

web/src/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>Web</title>
+  <base href="/">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <link rel="icon" type="image/x-icon" href="favicon.ico">
+</head>
+<body>
+  <app-root></app-root>
+</body>
+</html>

web/src/main.ts

@@ -0,0 +1,6 @@
+import { bootstrapApplication } from '@angular/platform-browser';
+import { appConfig } from './app/app.config';
+import { App } from './app/app';
+
+bootstrapApplication(App, appConfig)
+  .catch((err) => console.error(err));

web/src/styles.scss

@@ -0,0 +1 @@
+/* You can add global styles to this file, and also import other style files */

web/tsconfig.app.json

@@ -0,0 +1,14 @@
+/* To learn more about Typescript configuration file: https://www.typescriptlang.org/docs/handbook/tsconfig-json.html. */
+/* To learn more about Angular compiler options: https://angular.dev/reference/configs/angular-compiler-options. */
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "types": []
+  },
+  "include": [
+    "src/**/*.ts"
+  ],
+  "exclude": [
+    "src/**/*.spec.ts"
+  ]
+}

web/tsconfig.json

@@ -0,0 +1,31 @@
+/* To learn more about Typescript configuration file: https://www.typescriptlang.org/docs/handbook/tsconfig-json.html. */
+/* To learn more about Angular compiler options: https://angular.dev/reference/configs/angular-compiler-options. */
+{
+  "compileOnSave": false,
+  "compilerOptions": {
+    "noImplicitOverride": true,
+    "noPropertyAccessFromIndexSignature": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true,
+    "skipLibCheck": true,
+    "isolatedModules": true,
+    "experimentalDecorators": true,
+    "importHelpers": true,
+    "target": "ES2022",
+    "module": "preserve"
+  },
+  "angularCompilerOptions": {
+    "enableI18nLegacyMessageIdFormat": false,
+    "strictInjectionParameters": true,
+    "strictInputAccessModifiers": true
+  },
+  "files": [],
+  "references": [
+    {
+      "path": "./tsconfig.app.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
+  ]
+}

web/tsconfig.spec.json

@@ -0,0 +1,14 @@
+/* To learn more about Typescript configuration file: https://www.typescriptlang.org/docs/handbook/tsconfig-json.html. */
+/* To learn more about Angular compiler options: https://angular.dev/reference/configs/angular-compiler-options. */
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "types": [
+      "vitest/globals"
+    ]
+  },
+  "include": [
+    "src/**/*.d.ts",
+    "src/**/*.spec.ts"
+  ]
+}