All files / stream-counter/src/pages counter.tsx

100% Statements 94/94
100% Branches 9/9
100% Functions 5/5
100% Lines 94/94

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 1121x 1x   9x 9x   9x 9x 9x   9x 9x 3x 3x 9x 1x 1x 5x 9x   9x 9x 9x 9x 9x 9x 9x   9x   9x 9x 9x 9x 9x 9x 9x 9x 9x   9x 9x 9x   9x 9x 9x 9x 9x 9x 9x   9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x   9x   9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x   9x   9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x   9x 9x   9x 9x 9x 9x 9x 9x 9x 9x   9x 9x   9x  
import Link from "next/link";
import { useState } from "react";
 
export default function Counter() {
  const [count, setCount] = useState(0);
 
  const increment = () => setCount(count + 1);
  const decrement = () => setCount(count - 1);
  const reset = () => setCount(0);
 
  const getCounterColor = () => {
    if (count > 0) {
      return "#0070f3";
    }
    if (count < 0) {
      return "#ff4444";
    }
    return "#333";
  };
 
  return (
    <div
      style={{
        padding: "2rem",
        fontFamily: "Arial, sans-serif",
        textAlign: "center",
      }}
    >
      <h1>Stream Counter</h1>
 
      <div style={{ margin: "2rem 0" }}>
        <div
          data-testid="counter-value"
          style={{
            fontSize: "3rem",
            fontWeight: "bold",
            margin: "1rem 0",
            color: getCounterColor(),
          }}
        >
          {count}
        </div>
      </div>
 
      <div
        style={{
          display: "flex",
          gap: "1rem",
          justifyContent: "center",
          margin: "2rem 0",
        }}
      >
        <button
          onClick={decrement}
          style={{
            padding: "0.5rem 1rem",
            fontSize: "1rem",
            backgroundColor: "#ff4444",
            color: "white",
            border: "none",
            borderRadius: "4px",
            cursor: "pointer",
          }}
        >
          減少
        </button>
 
        <button
          onClick={reset}
          style={{
            padding: "0.5rem 1rem",
            fontSize: "1rem",
            backgroundColor: "#666",
            color: "white",
            border: "none",
            borderRadius: "4px",
            cursor: "pointer",
          }}
        >
          リセット
        </button>
 
        <button
          onClick={increment}
          style={{
            padding: "0.5rem 1rem",
            fontSize: "1rem",
            backgroundColor: "#00aa44",
            color: "white",
            border: "none",
            borderRadius: "4px",
            cursor: "pointer",
          }}
        >
          増加
        </button>
      </div>
 
      <Link
        href="/"
        style={{
          color: "#0070f3",
          textDecoration: "none",
          fontSize: "1rem",
        }}
      >
        ← ホームに戻る
      </Link>
    </div>
  );
}