feat: implement tests and coverage reports for KpiCards and scrapeLakes functionality

src/__tests__/translations.test.ts

@@ -0,0 +1,34 @@
+import { describe, it, expect } from 'vitest';
+import { t } from '../translations';
+
+describe('Translations', () => {
+  it('should have exactly the same keys in English and Czech', () => {
+    const enKeys = Object.keys(t.en).sort();
+    const csKeys = Object.keys(t.cs).sort();
+    
+    expect(enKeys).toEqual(csKeys);
+    
+    // Deep check for nested keys
+    for (const key of enKeys) {
+      const enSubKeys = Object.keys((t.en as any)[key]).sort();
+      const csSubKeys = Object.keys((t.cs as any)[key]).sort();
+      
+      expect(enSubKeys).toEqual(csSubKeys);
+    }
+  });
+
+  it('should not have empty translation strings', () => {
+    const checkEmpty = (obj: any) => {
+      for (const val of Object.values(obj)) {
+        if (typeof val === 'string') {
+          expect(val.length).toBeGreaterThan(0);
+        } else if (typeof val === 'object') {
+          checkEmpty(val);
+        }
+      }
+    };
+    
+    checkEmpty(t.en);
+    checkEmpty(t.cs);
+  });
+});

src/components/LakeDetail.tsx

@@ -41,7 +41,12 @@ const CustomTooltip = ({ active, payload, label, language, isWeather }: any) =>
     return (
       <div style={{ backgroundColor: 'var(--bg-card)', padding: '1rem', border: '1px solid var(--border-color)', borderRadius: '0.5rem', boxShadow: '0 4px 6px -1px rgba(0, 0, 0, 0.1)' }}>
         <p style={{ margin: '0 0 0.5rem 0', fontWeight: 'bold', color: 'var(--text-main)' }}>{label}</p>
-        {payload.map((entry: any, index: number) => {
+        {[...payload].sort((a: any, b: any) => {
+          const order = ['level', 'inflow', 'outflow'];
+          const indexA = order.indexOf(a.dataKey);
+          const indexB = order.indexOf(b.dataKey);
+          return (indexA === -1 ? 99 : indexA) - (indexB === -1 ? 99 : indexB);
+        }).map((entry: any, index: number) => {
            let labelStr = '';
            let unit = '';
            let color = '';
@@ -49,7 +54,7 @@ const CustomTooltip = ({ active, payload, label, language, isWeather }: any) =>
            else if (entry.dataKey === 'outflow') { labelStr = dict.outflow; unit = 'm³/s'; color = 'var(--color-orange)'; }
            else if (entry.dataKey === 'inflow') { labelStr = dict.inflow; unit = 'm³/s'; color = '#8b5cf6'; }
            
-           if (!labelStr || (entry.dataKey === 'inflow' && entry.value === 0)) return null;
+           if (!labelStr || entry.value === null || entry.value === undefined) return null;
            
            return (
              <div key={index} style={{ margin: 0, color: 'var(--text-main)', display: 'flex', alignItems: 'center', marginBottom: '4px' }}>
@@ -125,8 +130,8 @@ const LakeDetail = ({ language, lakeId }: Props) => {
   const latestData = data[data.length - 1] || { level: 0, inflow: 0, outflow: 0, volume: 0, fullness: 0 };
   const curveType = isSmoothed ? 'monotone' : 'linear';
 
-  // Find the last record that actually has flow data (often the very last record is incomplete on PVL)
-  const lastValidFlowData = [...data].reverse().find(d => d.outflow > 0) || latestData;
+  // Find last valid values for KPIs, including 0
+  const lastValidFlowData = [...data].reverse().find(d => d.outflow !== null && !isNaN(d.outflow) && d.outflow >= 0) || latestData;
 
   const now = new Date().getTime();
   const getCutoff = () => {

src/components/__tests__/KpiCards.test.tsx

@@ -0,0 +1,41 @@
+import { render, screen } from '@testing-library/react';
+import { describe, it, expect } from 'vitest';
+import KpiCards from '../KpiCards';
+
+describe('KpiCards Component', () => {
+  const mockData = {
+    level: 723.10,
+    inflow: 5.5,
+    outflow: 2.5,
+    volume: 150,
+    fullness: 80,
+    storageDiff: -1.81
+  };
+
+  it('renders correctly with negative storageDiff (red)', () => {
+    const { container } = render(<KpiCards data={mockData} language="cs" />);
+    
+    // ZÁSOBNÍ PROSTOR card should show -1.81 m
+    expect(screen.getByText('-1.81 m')).toBeInTheDocument();
+    
+    // Because it is negative, it should have the red color style applied
+    const diffElement = screen.getByText('-1.81 m');
+    expect(diffElement.parentElement?.outerHTML).toContain('var(--color-red)');
+  });
+
+  it('renders correctly with positive storageDiff (cyan)', () => {
+    const positiveData = { ...mockData, storageDiff: 0.5 };
+    render(<KpiCards data={positiveData} language="cs" />);
+    
+    expect(screen.getByText('+0.50 m')).toBeInTheDocument();
+    const diffElement = screen.getByText('+0.50 m');
+    expect(diffElement.parentElement?.outerHTML).toContain('var(--color-cyan)');
+  });
+
+  it('falls back to percentage fullness if storageDiff is zero/undefined', () => {
+    const noDiffData = { ...mockData, storageDiff: 0, fullness: 85.5 };
+    render(<KpiCards data={noDiffData} language="cs" />);
+    
+    expect(screen.getByText('85.5%')).toBeInTheDocument();
+  });
+});

src/test/setup.ts

@@ -0,0 +1 @@
+import '@testing-library/jest-dom';