Update constructor

Author: asamuzaK

lib/CSSStyleDeclaration.js

@@ -30,12 +30,12 @@ class CSSStyleDeclaration {
    * @param {object} globalObject - Window
    * @param {object} opt - Options
    * @param {object} opt.context - Element or CSSStyleRule
+   * @param {string} opt.format - "specifiedValue" or "computedValue"
    * @param {Function} opt.onChange - Callback when cssText is changed or the property is removed
-   * @param {boolean} opt.computed - The computed flag
    * @param {boolean} opt.readOnly - The read-only flag
    */
   constructor(globalObject = globalThis, opt = {}) {
-    const { context } = opt;
+    const { context, format, onChange, readOnly, ...styleOpts } = opt;
     this._global = globalObject;
     this._ownerNode = null;
     this._parentRule = null;
@@ -46,16 +46,20 @@ class CSSStyleDeclaration {
         this._parentRule = context;
       }
     }
-    this._onChange = opt.onChange;
-    this._readonly = Boolean(opt.readOnly);
+    this._onChange = onChange;
+    this._readonly = readOnly ?? false;
     this._computed = undefined;
-    if (opt.format === "computedValue") {
+    const styleOptions = {
+      ...styleOpts
+    };
+    if (format === "computedValue") {
       this._computed = true;
-    } else {
+      styleOptions.format = format;
+    } else if (format !== "specifiedValue") {
       // Set the default format value.
-      opt.format = "specifiedValue";
+      styleOptions.format = "specifiedValue";
     }
-    this._options = opt;
+    this._options = styleOptions;
     this._values = new Map();
     this._priorities = new Map();
     this._length = 0;