Fixed magic at on(...) function.

elastic · Jun 22, 2021 · 7c95c90 · 7c95c90
1 parent b9afc4a
commit 7c95c90
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Showing 4 changed files with 49 additions and 43 deletions.
diff --git a/src/plugins/expressions/common/expression_renderers/expression_handlers.ts b/src/plugins/expressions/common/expression_renderers/expression_handlers.ts
@@ -6,8 +6,37 @@
  * Side Public License, v 1.
  */
 
-import { DefaultInterpreterRenderHandlers, InterpreterRenderHandlers } from './types';
+import { InterpreterRenderHandlers, RenderMode } from './types';
 
-export function getDefaultHandlers<T = {}>(): InterpreterRenderHandlers<T> {
-  return new DefaultInterpreterRenderHandlers<T>() as InterpreterRenderHandlers<T>;
+function on<T>(this: T, event: keyof T, fn: (...args: any) => void): void {
+  const eventCall = this[event];
+  if (typeof eventCall !== 'function') return;
+
+  const updatedEvent = (...args: unknown[]) => {
+    const preventFromCallingListener: void | boolean = eventCall(...args);
+    if (typeof fn === 'function' && !preventFromCallingListener) {
+      fn(...args);
+    }
+    return preventFromCallingListener;
+  };
+  this[event] = (updatedEvent as unknown) as typeof eventCall;
+}
+
+export function getDefaultHandlers<T>(): InterpreterRenderHandlers<T> {
+  const handlers = {
+    done() {},
+    onDestroy(fn: () => void) {},
+    reload() {},
+    update(params: any) {},
+    event(event: any) {},
+    getRenderMode() {
+      return 'noInteractivity' as RenderMode;
+    },
+    isSyncColorsEnabled() {
+      return false;
+    },
+    on,
+  } as InterpreterRenderHandlers<T>;
+
+  return handlers;
 }
diff --git a/src/plugins/expressions/common/expression_renderers/types.ts b/src/plugins/expressions/common/expression_renderers/types.ts
@@ -72,7 +72,7 @@ export interface IInterpreterRenderHandlers {
   hasCompatibleActions?: (event: any) => Promise<boolean>;
   getRenderMode: () => RenderMode;
   isSyncColorsEnabled: () => boolean;
-  on: (event: any, fn: (...args: any) => void) => void;
+  on: (this: any, event: any, fn: (...args: any) => void) => void;
   /**
    * This uiState interface is actually `PersistedState` from the visualizations plugin,
    * but expressions cannot know about vis or it creates a mess of circular dependencies.
@@ -83,37 +83,16 @@ export interface IInterpreterRenderHandlers {
 
 type DefaultEmitters<T extends IInterpreterRenderHandlers> = Pick<T, 'done' | 'reload' | 'update'>;
 
-export class DefaultInterpreterRenderHandlers<Emitters = {}> implements IInterpreterRenderHandlers {
-  done() {}
-  onDestroy(fn: () => void) {}
-  reload() {}
-  update(params: any) {}
-  event(event: any) {}
-  getRenderMode() {
-    return 'noInteractivity' as RenderMode;
-  }
-  isSyncColorsEnabled() {
-    return false;
-  }
-  hasCompatibleActions?: (event: any) => Promise<boolean>;
-
-  on(event: keyof Emitters | keyof DefaultEmitters<this>, fn: (...args: any) => void): void {
-    const eventName = event as keyof this;
-    const eventCall = this[eventName];
-    if (typeof eventCall !== 'function') return;
-
-    const updatedEvent = (...args: unknown[]) => {
-      const preventFromCallingListener: void | boolean = eventCall(...args);
-      if (typeof fn === 'function' && !preventFromCallingListener) {
-        fn(...args);
-      }
-      return preventFromCallingListener;
-    };
-    this[eventName] = (updatedEvent as unknown) as typeof eventCall;
-  }
-
-  uiState?: unknown;
-}
+type DefaultInterpreterRenderHandlers<Emitters = {}> = IInterpreterRenderHandlers &
+  {
+    [K in keyof Emitters]: Emitters[K];
+  } & {
+    on: (
+      this: any,
+      event: keyof Emitters | keyof DefaultEmitters<IInterpreterRenderHandlers>,
+      fn: (...args: any) => void
+    ) => void;
+  };
 
 export type InterpreterRenderHandlers<Emitters = {}> = Emitters &
   DefaultInterpreterRenderHandlers<Emitters>;
diff --git a/src/plugins/expressions/public/render.ts b/src/plugins/expressions/public/render.ts
@@ -76,8 +76,9 @@ export class ExpressionRenderHandler {
 
     this.updateSubject = new Rx.Subject();
     this.update$ = this.updateSubject.asObservable();
-    this.handlers = getDefaultHandlers();
-    this.handlers = Object.assign(this.handlers, {
+    const handlers = getDefaultHandlers();
+    this.handlers = {
+      ...handlers,
       onDestroy: (fn: any) => {
         this.destroyFn = fn;
       },
@@ -102,7 +103,7 @@ export class ExpressionRenderHandler {
         return syncColors || false;
       },
       hasCompatibleActions,
-    });
+    };
   }
 
   render = async (value: any, uiState?: any) => {

diff --git a/x-pack/plugins/canvas/public/lib/create_handlers.ts b/x-pack/plugins/canvas/public/lib/create_handlers.ts
@@ -22,10 +22,8 @@ import {
 
 // We need to move towards only using these handlers and ditching our canvas specific ones
 export const createHandlers = (): InterpreterRenderHandlers<CanvasSpecificRendererHandlers> => {
-  const defaultHandlers = getDefaultHandlers<CanvasSpecificRendererHandlers>();
-
-  const handlers: Partial<typeof defaultHandlers> = {
-    ...defaultHandlers,
+  return {
+    ...getDefaultHandlers<CanvasSpecificRendererHandlers>(),
     destroy() {},
     getElementId() {
       return '';
@@ -46,7 +44,6 @@ export const createHandlers = (): InterpreterRenderHandlers<CanvasSpecificRender
     embeddableInputChange() {},
     resize(_size: { height: number; width: number }) {},
   };
-  return Object.assign(defaultHandlers, handlers);
 };
 
 export const assignHandlers = (