Resolve perf regression from OptionsService.options

src/browser/public/Terminal.ts

@@ -30,18 +30,16 @@ export class Terminal implements ITerminalApi {
     this._core = new TerminalCore(options);
     this._addonManager = new AddonManager();
 
-    this._publicOptions = {};
-    for (const propName in this._core.options) {
-      Object.defineProperty(this._publicOptions, propName, {
-        get: () => {
-          return this._core.options[propName];
-        },
-        set: (value: any) => {
-          this._checkReadonlyOptions(propName);
-          this._core.options[propName] = value;
-        }
-      });
-    }
+    this._publicOptions = new Proxy(this._core.options, {
+      get: (target, propName: string): any => {
+        return target[propName];
+      },
+      set: (target, propName: string, value): any => {
+        this._checkReadonlyOptions(propName);
+        target[propName] = value;
+        return true;
+      }
+    });
   }
 
   private _checkReadonlyOptions(propName: string): void {

src/common/services/OptionsService.test.ts

@@ -10,7 +10,7 @@ describe('OptionsService', () => {
   describe('constructor', () => {
     const originalError = console.error;
     beforeEach(() => {
-      console.error = () => {};
+      console.error = () => { };
     });
     afterEach(() => {
       console.error = originalError;
@@ -26,7 +26,7 @@ describe('OptionsService', () => {
       assert.equal(optionsService.getOption('cols'), 80);
     });
     it('uses default value if invalid constructor option value passed', () => {
-      assert.equal(new OptionsService({tabStopWidth: 0}).getOption('tabStopWidth'), DEFAULT_OPTIONS.tabStopWidth);
+      assert.equal(new OptionsService({ tabStopWidth: 0 }).getOption('tabStopWidth'), DEFAULT_OPTIONS.tabStopWidth);
     });
   });
   describe('setOption', () => {

src/common/services/OptionsService.ts

@@ -60,55 +60,51 @@ const FONT_WEIGHT_OPTIONS: Extract<FontWeight, string>[] = ['normal', 'bold', '1
 export class OptionsService implements IOptionsService {
   public serviceBrand: any;
 
-  private _options: ITerminalOptions;
   public options: ITerminalOptions;
 
   private _onOptionChange = new EventEmitter<string>();
   public get onOptionChange(): IEvent<string> { return this._onOptionChange.event; }
 
   constructor(options: Partial<ITerminalOptions>) {
     // set the default value of each option
-    this._options = { ...DEFAULT_OPTIONS };
+    const defaultOptions = { ...DEFAULT_OPTIONS };
     for (const key in options) {
-      if (key in this._options) {
+      if (key in defaultOptions) {
         try {
           const newValue = options[key];
-          this._options[key] = this._sanitizeAndValidateOption(key, newValue);
+          defaultOptions[key] = this._sanitizeAndValidateOption(key, newValue);
         } catch (e) {
           console.error(e);
         }
       }
     }
 
     // set up getters and setters for each option
-    this.options = this._setupOptions(this._options);
+    this.options = this._setupOptions(defaultOptions);
   }
 
   private _setupOptions(options: ITerminalOptions): ITerminalOptions {
-    const copiedOptions = { ... options };
-    for (const propName in copiedOptions) {
-      Object.defineProperty(copiedOptions, propName, {
-        get: () => {
-          if (!(propName in DEFAULT_OPTIONS)) {
-            throw new Error(`No option with key "${propName}"`);
-          }
-          return this._options[propName];
-        },
-        set: (value: any) => {
-          if (!(propName in DEFAULT_OPTIONS)) {
-            throw new Error(`No option with key "${propName}"`);
-          }
+    return new Proxy(options, {
+      get: (target, propName: string): any => {
+        if (!(propName in DEFAULT_OPTIONS)) {
+          throw new Error(`No option with key "${propName}"`);
+        }
+        return target[propName];
+      },
+      set: (target, propName: string, value): any => {
+        if (!(propName in DEFAULT_OPTIONS)) {
+          throw new Error(`No option with key "${propName}"`);
+        }
 
-          value = this._sanitizeAndValidateOption(propName, value);
-          // Don't fire an option change event if they didn't change
-          if (this._options[propName] !== value) {
-            this._options[propName] = value;
-            this._onOptionChange.fire(propName);
-          }
+        value = this._sanitizeAndValidateOption(propName, value);
+        // Don't fire an option change event if they didn't change
+        if (target[propName] !== value) {
+          target[propName] = value;
+          this._onOptionChange.fire(propName);
         }
-      });
-    }
-    return copiedOptions;
+        return true;
+      }
+    });
   }
 
   public setOption(key: string, value: any): void {