Node.js 環境變數 false 仍然啟用？process.env 布林解析與啟動檢查

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import assert from 'node:assert/strict';
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function parseEnvBoolean(raw, fallback = false) {
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  if (typeof fallback !== 'boolean') throw new TypeError('預設值必須是布林');
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  if (raw === undefined) return fallback;
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  if (raw === 'true') return true;
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  if (raw === 'false') return false;
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  throw new TypeError('設定只接受 true 或 false');
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}
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assert.equal(Boolean('false'), true);
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assert.equal(parseEnvBoolean('false'), false);
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assert.equal(parseEnvBoolean('true'), true);
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assert.equal(parseEnvBoolean(undefined), false);
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assert.equal(parseEnvBoolean(undefined, true), true);
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for (const raw of ['', '0', '1', 'TRUE', ' true ', 'ture', false, null]) {
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  assert.throws(() => parseEnvBoolean(raw), TypeError);
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}
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assert.throws(() => parseEnvBoolean(undefined, 'false'), TypeError);
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console.log('布林解析契約檢查通過');

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import assert from 'node:assert/strict';
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import { execFileSync } from 'node:child_process';
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const output = execFileSync(process.execPath, ['-e', `
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  const raw = process.env.FEATURE_ENABLED;
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  console.log(JSON.stringify({ type: typeof raw, raw, truthy: Boolean(raw) }));
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`], {
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  env: { FEATURE_ENABLED: 'false' },
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  encoding: 'utf8',
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});
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assert.deepEqual(JSON.parse(output), {
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  type: 'string', raw: 'false', truthy: true,
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});
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console.log('子程序環境字串檢查通過');