Refactor to add readonly interfaces

Using more granular interfaces adds to expressiveness of the code.
Knowing what needs to mutate the state explicitly helps easier
understanding of the code and therefore increases the maintainability.

src/application/Context/IApplicationContext.ts

@@ -1,12 +1,16 @@
-import { ICategoryCollectionState } from './State/ICategoryCollectionState';
+import { ICategoryCollectionState, IReadOnlyCategoryCollectionState } from './State/ICategoryCollectionState';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 import { IEventSource } from '@/infrastructure/Events/IEventSource';
 import { IApplication } from '@/domain/IApplication';
 
-export interface IApplicationContext {
+export interface IReadOnlyApplicationContext {
     readonly app: IApplication;
-    readonly state: ICategoryCollectionState;
+    readonly state: IReadOnlyCategoryCollectionState;
     readonly contextChanged: IEventSource<IApplicationContextChangedEvent>;
+}
+
+export interface IApplicationContext extends IReadOnlyApplicationContext {
+    readonly state: ICategoryCollectionState;
     changeContext(os: OperatingSystem): void;
 }
 

src/application/Context/State/CategoryCollectionState.ts

@@ -5,7 +5,7 @@ import { UserSelection } from './Selection/UserSelection';
 import { IUserSelection } from './Selection/IUserSelection';
 import { ICategoryCollectionState } from './ICategoryCollectionState';
 import { IApplicationCode } from './Code/IApplicationCode';
-import { ICategoryCollection } from '../../../domain/ICategoryCollection';
+import { ICategoryCollection } from '@/domain/ICategoryCollection';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 
 export class CategoryCollectionState implements ICategoryCollectionState {

src/application/Context/State/Code/ApplicationCode.ts

@@ -2,7 +2,7 @@ import { CodeChangedEvent } from './Event/CodeChangedEvent';
 import { CodePosition } from './Position/CodePosition';
 import { ICodeChangedEvent } from './Event/ICodeChangedEvent';
 import { SelectedScript } from '@/application/Context/State/Selection/SelectedScript';
-import { IUserSelection } from '@/application/Context/State/Selection/IUserSelection';
+import { IReadOnlyUserSelection } from '@/application/Context/State/Selection/IUserSelection';
 import { UserScriptGenerator } from './Generation/UserScriptGenerator';
 import { EventSource } from '@/infrastructure/Events/EventSource';
 import { IApplicationCode } from './IApplicationCode';
@@ -16,7 +16,7 @@ export class ApplicationCode implements IApplicationCode {
     private scriptPositions = new Map<SelectedScript, CodePosition>();
 
     constructor(
-        userSelection: IUserSelection,
+        userSelection: IReadOnlyUserSelection,
         private readonly scriptingDefinition: IScriptingDefinition,
         private readonly generator: IUserScriptGenerator = new UserScriptGenerator()) {
         if (!userSelection) { throw new Error('userSelection is null or undefined'); }

src/application/Context/State/Filter/IUserFilter.ts

@@ -1,10 +1,13 @@
 import { IEventSource } from '@/infrastructure/Events/IEventSource';
 import { IFilterResult } from './IFilterResult';
 
-export interface IUserFilter {
+export interface IReadOnlyUserFilter {
     readonly currentFilter: IFilterResult | undefined;
     readonly filtered: IEventSource<IFilterResult>;
     readonly filterRemoved: IEventSource<void>;
+}
+
+export interface IUserFilter extends IReadOnlyUserFilter {
     setFilter(filter: string): void;
     removeFilter(): void;
 }

src/application/Context/State/ICategoryCollectionState.ts

@@ -1,13 +1,18 @@
-import { IUserFilter } from './Filter/IUserFilter';
-import { IUserSelection } from './Selection/IUserSelection';
+import { IReadOnlyUserFilter, IUserFilter } from './Filter/IUserFilter';
+import { IReadOnlyUserSelection, IUserSelection } from './Selection/IUserSelection';
 import { IApplicationCode } from './Code/IApplicationCode';
 import { ICategoryCollection } from '@/domain/ICategoryCollection';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 
-export interface ICategoryCollectionState {
+export interface IReadOnlyCategoryCollectionState {
     readonly code: IApplicationCode;
+    readonly os: OperatingSystem;
+    readonly filter: IReadOnlyUserFilter;
+    readonly selection: IReadOnlyUserSelection;
+    readonly collection: ICategoryCollection;
+}
+
+export interface ICategoryCollectionState extends IReadOnlyCategoryCollectionState {
     readonly filter: IUserFilter;
     readonly selection: IUserSelection;
-    readonly collection: ICategoryCollection;
-    readonly os: OperatingSystem;
 }

src/application/Context/State/Selection/IUserSelection.ts

@@ -3,18 +3,21 @@ import { IScript } from '@/domain/IScript';
 import { ICategory } from '@/domain/ICategory';
 import { IEventSource } from '@/infrastructure/Events/IEventSource';
 
-export interface IUserSelection {
+export interface IReadOnlyUserSelection {
     readonly changed: IEventSource<ReadonlyArray<SelectedScript>>;
     readonly selectedScripts: ReadonlyArray<SelectedScript>;
+    isSelected(scriptId: string): boolean;
     areAllSelected(category: ICategory): boolean;
     isAnySelected(category: ICategory): boolean;
+}
+
+export interface IUserSelection extends IReadOnlyUserSelection {
     removeAllInCategory(categoryId: number): void;
     addOrUpdateAllInCategory(categoryId: number, revert: boolean): void;
     addSelectedScript(scriptId: string, revert: boolean): void;
     addOrUpdateSelectedScript(scriptId: string, revert: boolean): void;
     removeSelectedScript(scriptId: string): void;
     selectOnly(scripts: ReadonlyArray<IScript>): void;
-    isSelected(scriptId: string): boolean;
     selectAll(): void;
     deselectAll(): void;
 }