test(app): 補齊 isSafeRepoPath/extractBalancedJSON/normalizeText/repairJSONArrayWithAI/格式化函式測試

為可測性 export 三個內部函式（isSafeRepoPath、extractBalancedJSON/extractJSONText、normalizeText）。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/test/findings.test.js

@@ -3,7 +3,7 @@ import assert from 'node:assert/strict';
 import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
-import { loadOldFindings, loadExclusions, applyExclusions, filterFalsePositivesWithAI, appendExclusions, resolveMissingLineNumbers } from '../findings.js';
+import { loadOldFindings, loadExclusions, applyExclusions, filterFalsePositivesWithAI, appendExclusions, resolveMissingLineNumbers, normalizeText } from '../findings.js';
 import { EXCLUSIONS_PATH, FINDINGS_PATH } from '../config.js';
 
 describe('findings exclusions', () => {
@@ -349,3 +349,47 @@ describe('findings exclusions', () => {
     assert.ok(logs.some(line => line.includes(`path=${path.relative(workspace, fullPath)}`)));
   });
 });
+
+describe('normalizeText', () => {
+  it('normalizes full-width characters to the same result as half-width lowercase (NFKC)', () => {
+    // NFKC 將全形 ＡＢＣ 折成半形 ABC，再小寫 → 'abc'，與 'abc' 一致
+    assert.equal(normalizeText('ＡＢＣ'), 'abc');
+    assert.equal(normalizeText('abc'), 'abc');
+    assert.equal(normalizeText('ＡＢＣ'), normalizeText('abc'));
+  });
+
+  it('collapses mixed punctuation and symbols into single spaces', () => {
+    assert.equal(normalizeText('Hello, World!! foo@bar'), 'hello world foo bar');
+  });
+
+  it('collapses multiple spaces, newlines and tabs into a single space and trims', () => {
+    assert.equal(normalizeText('  multiple   \n\t spaces \n here  '), 'multiple spaces here');
+  });
+
+  it('lowercases uppercase input', () => {
+    assert.equal(normalizeText('UPPER Case Mix'), 'upper case mix');
+  });
+
+  it('returns empty string for non-string inputs', () => {
+    assert.equal(normalizeText(null), '');
+    assert.equal(normalizeText(undefined), '');
+    assert.equal(normalizeText(42), '');
+    assert.equal(normalizeText({ a: 1 }), '');
+  });
+
+  it('returns empty string for empty string input', () => {
+    assert.equal(normalizeText(''), '');
+  });
+
+  it('strips surrounding full-width whitespace and collapses CJK punctuation', () => {
+    // 全形空白被 trim、，與 ！屬於 \p{P} 折成單一空白 → '你好 世界'
+    assert.equal(normalizeText('　你好，世界！　'), '你好 世界');
+    assert.equal(normalizeText('（重要）測試：項目#1'), '重要 測試 項目 1');
+  });
+
+  it('is idempotent', () => {
+    for (const input of ['ＡＢＣ', 'Hello, World!! foo@bar', '　你好，世界！　', 'UPPER Case Mix', '']) {
+      assert.equal(normalizeText(normalizeText(input)), normalizeText(input));
+    }
+  });
+});