Fix processor registration and subscription removal

src/processors/LayoutProcessorsStore.test.ts

@@ -27,4 +27,31 @@ describe('Layout processors Store', () => {
     remove();
     expect(uut.getProcessors()).toEqual([]);
   });
+
+  it('should unregister only the subscribed processor', () => {
+    const firstProcessor = (value: any, _commandName: string) => value;
+    const secondProcessor = (value: any, _commandName: string) => value;
+    const thirdProcessor = (value: any, _commandName: string) => value;
+    uut.addProcessor(firstProcessor);
+    const { remove } = uut.addProcessor(secondProcessor);
+    uut.addProcessor(thirdProcessor);
+
+    remove();
+
+    expect(uut.getProcessors()).toEqual([firstProcessor, thirdProcessor]);
+  });
+
+  it('should ignore repeated subscription removal', () => {
+    const processor = (value: any, _commandName: string) => value;
+    const firstSubscription = uut.addProcessor(processor);
+    const secondSubscription = uut.addProcessor(processor);
+
+    firstSubscription.remove();
+    firstSubscription.remove();
+
+    expect(uut.getProcessors()).toEqual([processor]);
+
+    secondSubscription.remove();
+    expect(uut.getProcessors()).toEqual([]);
+  });
 });

src/processors/LayoutProcessorsStore.ts

@@ -6,15 +6,24 @@ export class LayoutProcessorsStore {
 
   public addProcessor(processor: LayoutProcessor): ProcessorSubscription {
     this.layoutProcessors.push(processor);
+    let removed = false;
 
-    return { remove: () => this.removeProcessor(processor) };
+    return {
+      remove: () => {
+        if (!removed) {
+          this.removeProcessor(processor);
+          removed = true;
+        }
+      },
+    };
   }
 
   public getProcessors(): LayoutProcessor[] {
     return this.layoutProcessors;
   }
 
   private removeProcessor(processor: LayoutProcessor) {
-    this.layoutProcessors.splice(this.layoutProcessors.indexOf(processor));
+    const index = this.layoutProcessors.indexOf(processor);
+    if (index !== -1) this.layoutProcessors.splice(index, 1);
   }
 }

src/processors/OptionProcessorsStore.test.ts

@@ -20,11 +20,47 @@ describe('Option processors Store', () => {
     expect(uut.getProcessors('topBar')).toEqual([processor, secondProcessor]);
   });
 
+  it.each(['toString', '__proto__'])(
+    'should register processors for the %s object path',
+    (optionPath) => {
+      const processor = (value: any, _commandName: string) => value;
+      uut.addProcessor(optionPath, processor);
+      expect(uut.getProcessors(optionPath)).toEqual([processor]);
+    }
+  );
+
   it('should unregister processor', () => {
     const processor = (value: any, _commandName: string) => value;
     const { remove } = uut.addProcessor('topBar', processor);
     expect(uut.getProcessors('topBar')).toEqual([processor]);
     remove();
     expect(uut.getProcessors('topBar')).toEqual([]);
   });
+
+  it('should unregister only the subscribed processor', () => {
+    const firstProcessor = (value: any, _commandName: string) => value;
+    const secondProcessor = (value: any, _commandName: string) => value;
+    const thirdProcessor = (value: any, _commandName: string) => value;
+    uut.addProcessor('topBar', firstProcessor);
+    const { remove } = uut.addProcessor('topBar', secondProcessor);
+    uut.addProcessor('topBar', thirdProcessor);
+
+    remove();
+
+    expect(uut.getProcessors('topBar')).toEqual([firstProcessor, thirdProcessor]);
+  });
+
+  it('should ignore repeated subscription removal', () => {
+    const processor = (value: any, _commandName: string) => value;
+    const firstSubscription = uut.addProcessor('topBar', processor);
+    const secondSubscription = uut.addProcessor('topBar', processor);
+
+    firstSubscription.remove();
+    firstSubscription.remove();
+
+    expect(uut.getProcessors('topBar')).toEqual([processor]);
+
+    secondSubscription.remove();
+    expect(uut.getProcessors('topBar')).toEqual([]);
+  });
 });

src/processors/OptionProcessorsStore.ts

@@ -2,7 +2,9 @@ import { ProcessorSubscription } from '../interfaces/ProcessorSubscription';
 import { OptionsProcessor } from '../interfaces/Processors';
 
 export class OptionProcessorsStore {
-  private optionsProcessorsByObjectPath: Record<string, OptionsProcessor<any>[]> = {};
+  private optionsProcessorsByObjectPath: Record<string, OptionsProcessor<any>[]> = Object.create(
+    null
+  );
 
   public addProcessor<T>(
     optionPath: string,
@@ -12,17 +14,25 @@ export class OptionProcessorsStore {
       this.optionsProcessorsByObjectPath[optionPath] = [];
 
     this.optionsProcessorsByObjectPath[optionPath].push(processor);
+    let removed = false;
 
-    return { remove: () => this.removeProcessor(optionPath, processor) };
+    return {
+      remove: () => {
+        if (!removed) {
+          this.removeProcessor(optionPath, processor);
+          removed = true;
+        }
+      },
+    };
   }
 
   public getProcessors(optionPath: string) {
     return this.optionsProcessorsByObjectPath[optionPath];
   }
 
   private removeProcessor(optionPath: string, processor: OptionsProcessor<any>) {
-    this.optionsProcessorsByObjectPath[optionPath].splice(
-      this.optionsProcessorsByObjectPath[optionPath].indexOf(processor)
-    );
+    const processors = this.optionsProcessorsByObjectPath[optionPath];
+    const index = processors.indexOf(processor);
+    if (index !== -1) processors.splice(index, 1);
   }
 }