increase test coverage

extend test coverage

tests/unit/configobj.test.js

@@ -0,0 +1,44 @@
+import ConfigObj, { regexEscape } from '../../src/editor/ConfigObj.js'
+
+describe('ConfigObj', () => {
+  const stubEditor = () => ({
+    storage: {
+      map: new Map(),
+      getItem (k) { return this.map.get(k) },
+      setItem (k, v) { this.map.set(k, v) }
+    },
+    loadFromDataURI: () => { stubEditor.loaded = 'data' },
+    loadFromString: () => { stubEditor.loaded = 'string' },
+    loadFromURL: () => { stubEditor.loaded = 'url' }
+  })
+
+  it('escapes regex characters', () => {
+    expect(regexEscape('a+b?')).toBe('a\\+b\\?')
+  })
+
+  it('merges defaults and respects allowInitialUserOverride', () => {
+    const editor = stubEditor()
+    const cfg = new ConfigObj(editor)
+    cfg.setConfig({ gridSnapping: true, userExtensions: ['custom'] })
+    cfg.setupCurConfig()
+
+    expect(cfg.curConfig.gridSnapping).toBe(true)
+    expect(cfg.curConfig.extensions).toContain('ext-grid')
+    expect(cfg.curConfig.extensions.includes('custom') || cfg.curConfig.userExtensions.includes('custom')).toBe(true)
+
+    cfg.setConfig({ lang: 'fr' }, { allowInitialUserOverride: true })
+    expect(cfg.defaultPrefs.lang).toBe('fr')
+  })
+
+  it('prefers existing values when overwrite is false', () => {
+    const editor = stubEditor()
+    const cfg = new ConfigObj(editor)
+    cfg.curConfig.preventAllURLConfig = true
+    cfg.curPrefs.lang = 'es'
+
+    cfg.setConfig({ lang: 'de', gridColor: '#fff', extensions: ['x'] }, { overwrite: false })
+    expect(cfg.curPrefs.lang).toBe('es')
+    expect(cfg.curConfig.gridColor).toBeUndefined()
+    expect(cfg.curConfig.extensions).toEqual([])
+  })
+})