Improved typing of ListProperty.

README.md

@@ -8,15 +8,17 @@ See [features](./FEATURES.md) for a list of features, planned features and bugs.
 
 ### Getting Started
 
-1. Install Yarn ([https://yarnpkg.com/](https://yarnpkg.com/))
+1. Install Node.js ([https://nodejs.org/](https://nodejs.org/))
-2. cd to the project directory
+2. Install Yarn ([https://yarnpkg.com/](https://yarnpkg.com/))
-3. Install dependencies with `yarn`
+3. `cd` to the project directory
-4. Launch server on [http://localhost:1623/](http://localhost:1623/) with `yarn start`
+4. Install dependencies with `yarn`
-5. src/index.ts is the application's entry point
+5. Launch server on [http://localhost:1623/](http://localhost:1623/) with `yarn start`
+6. src/index.ts is the application's entry point
 
-### Tests
+### Unit Tests
 
-Run tests with `yarn test` (or `yarn test --watch`). The testing framework used is Jest.
+Run the unit tests with `yarn test` or `yarn test --watch` if you want the relevant tests to be
+re-run whenever a file is changed. The testing framework used is Jest.
 
 ### Linting and Code Formatting
 

src/core/gui/ComboBox.ts

@@ -9,7 +9,7 @@ import { WritableProperty } from "../observable/property/WritableProperty";
 import { WidgetProperty } from "../observable/property/WidgetProperty";
 
 export type ComboBoxOptions<T> = LabelledControlOptions & {
-    items: T[] | Property<T[]>;
+    items: readonly T[] | Property<readonly T[]>;
     to_label(item: T): string;
     placeholder_text?: string;
     filter?(text: string): void;

src/core/gui/Menu.ts

@@ -11,7 +11,7 @@ export class Menu<T> extends Widget {
     readonly selected: WritableProperty<T | undefined>;
 
     private readonly to_label: (element: T) => string;
-    private readonly items: Property<T[]>;
+    private readonly items: Property<readonly T[]>;
     private readonly inner_element = el.div({ class: "core_Menu_inner" });
     private readonly related_element: HTMLElement;
     private readonly _selected: WidgetProperty<T | undefined>;
@@ -19,7 +19,7 @@ export class Menu<T> extends Widget {
     private hovered_element?: HTMLElement;
 
     constructor(
-        items: T[] | Property<T[]>,
+        items: readonly T[] | Property<readonly T[]>,
         to_label: (element: T) => string,
         related_element: HTMLElement,
     ) {
@@ -34,7 +34,7 @@ export class Menu<T> extends Widget {
         this.element.append(this.inner_element);
 
         this.to_label = to_label;
-        this.items = Array.isArray(items) ? property(items) : items;
+        this.items = Array.isArray(items) ? property(items) : (items as Property<readonly T[]>);
         this.related_element = related_element;
 
         this._selected = new WidgetProperty<T | undefined>(this, undefined, this.set_selected);

src/core/gui/Select.ts

@@ -25,7 +25,7 @@ export class Select<T> extends LabelledControl {
     private just_opened: boolean;
 
     constructor(
-        items: T[] | Property<T[]>,
+        items: readonly T[] | Property<readonly T[]>,
         to_label: (element: T) => string,
         options?: SelectOptions<T>,
     ) {

src/core/gui/dom.ts

@@ -232,7 +232,7 @@ export function bind_children_to<T>(
         }
     });
 
-    function splice_children(index: number, removed_count: number, inserted: T[]): void {
+    function splice_children(index: number, removed_count: number, inserted: readonly T[]): void {
         for (let i = 0; i < removed_count; i++) {
             element.children[index].remove();
         }

src/core/observable/property/list/ListProperty.ts

@@ -12,17 +12,17 @@ export type ListPropertyChangeEvent<T> = ListChange<T> | ListValueChange<T>;
 export type ListChange<T> = {
     readonly type: ListChangeType.ListChange;
     readonly index: number;
-    readonly removed: T[];
+    readonly removed: readonly T[];
-    readonly inserted: T[];
+    readonly inserted: readonly T[];
 };
 
 export type ListValueChange<T> = {
     readonly type: ListChangeType.ValueChange;
     readonly index: number;
-    readonly updated: T[];
+    readonly updated: readonly T[];
 };
 
-export interface ListProperty<T> extends Property<T[]> {
+export interface ListProperty<T> extends Property<readonly T[]> {
     readonly is_list_property: true;
 
     readonly length: Property<number>;
@@ -32,10 +32,8 @@ export interface ListProperty<T> extends Property<T[]> {
     observe_list(observer: (change: ListPropertyChangeEvent<T>) => void): Disposable;
 }
 
-export function is_list_property<T>(observable: Observable<T[]>): observable is ListProperty<T> {
+export function is_list_property<T>(
+    observable: Observable<readonly T[]>,
+): observable is ListProperty<T> {
     return (observable as any).is_list_property;
 }
-
-export function is_any_list_property(observable: any): observable is ListProperty<any> {
-    return observable && observable.is_list_property;
-}

src/core/observable/property/list/SimpleListProperty.ts

@@ -10,17 +10,17 @@ import Logger from "js-logger";
 
 const logger = Logger.get("core/observable/property/list/SimpleListProperty");
 
-export class SimpleListProperty<T> extends AbstractProperty<T[]>
+export class SimpleListProperty<T> extends AbstractProperty<readonly T[]>
     implements WritableListProperty<T> {
     readonly is_list_property = true;
 
     readonly length: Property<number>;
 
-    get val(): T[] {
+    get val(): readonly T[] {
         return this.get_val();
     }
 
-    set val(values: T[]) {
+    set val(values: readonly T[]) {
         this.set_val(values);
     }
 
@@ -28,7 +28,7 @@ export class SimpleListProperty<T> extends AbstractProperty<T[]>
         return this.values;
     }
 
-    set_val(values: T[]): T[] {
+    set_val(values: readonly T[]): T[] {
         const removed = this.values.splice(0, this.values.length, ...values);
         this.finalize_update({
             type: ListChangeType.ListChange,
@@ -95,9 +95,9 @@ export class SimpleListProperty<T> extends AbstractProperty<T[]>
         };
     }
 
-    bind_to(observable: Observable<T[]>): Disposable {
+    bind_to(observable: Observable<readonly T[]>): Disposable {
         if (is_list_property(observable)) {
-            this.val = observable.val;
+            this.set_val(observable.val);
 
             return observable.observe_list(change => {
                 if (change.type === ListChangeType.ListChange) {
@@ -106,14 +106,14 @@ export class SimpleListProperty<T> extends AbstractProperty<T[]>
             });
         } else {
             if (is_property(observable)) {
-                this.val = observable.val;
+                this.set_val(observable.val);
             }
 
             return observable.observe(({ value }) => this.set_val(value));
         }
     }
 
-    bind_bi(property: WritableProperty<T[]>): Disposable {
+    bind_bi(property: WritableProperty<readonly T[]>): Disposable {
         const bind_1 = this.bind_to(property);
         const bind_2 = property.bind_to(this);
         return {
@@ -253,7 +253,11 @@ export class SimpleListProperty<T> extends AbstractProperty<T[]>
         }
     }
 
-    private replace_element_observers(from: number, amount: number, new_elements: T[]): void {
+    private replace_element_observers(
+        from: number,
+        amount: number,
+        new_elements: readonly T[],
+    ): void {
         let index = from;
 
         const removed = this.value_observers.splice(

src/core/observable/property/list/WritableListProperty.ts

@@ -1,17 +1,17 @@
 import { ListProperty } from "./ListProperty";
 import { WritableProperty } from "../WritableProperty";
 
-export interface WritableListProperty<T> extends ListProperty<T>, WritableProperty<T[]> {
+export interface WritableListProperty<T> extends ListProperty<T>, WritableProperty<readonly T[]> {
-    val: T[];
+    val: readonly T[];
 
     set(index: number, value: T): void;
 
     push(...values: T[]): number;
 
     splice(index: number, delete_count?: number): T[];
-    splice(index: number, delete_count: number, ...values: T[]): T[];
+    splice(index: number, delete_count: number, ...values: readonly T[]): T[];
 
-    remove(...values: T[]): void;
+    remove(...values: readonly T[]): void;
 
     clear(): void;
 

src/hunt_optimizer/persistence/HuntMethodPersister.ts

@@ -6,7 +6,7 @@ import { Duration } from "luxon";
 const METHOD_USER_TIMES_KEY = "HuntMethodStore.methodUserTimes";
 
 class HuntMethodPersister extends Persister {
-    persist_method_user_times(hunt_methods: HuntMethodModel[], server: Server): void {
+    persist_method_user_times(hunt_methods: readonly HuntMethodModel[], server: Server): void {
         const user_times: PersistedUserTimes = {};
 
         for (const method of hunt_methods) {
@@ -18,7 +18,10 @@ class HuntMethodPersister extends Persister {
         this.persist_for_server(server, METHOD_USER_TIMES_KEY, user_times);
     }
 
-    async load_method_user_times(hunt_methods: HuntMethodModel[], server: Server): Promise<void> {
+    async load_method_user_times(
+        hunt_methods: readonly HuntMethodModel[],
+        server: Server,
+    ): Promise<void> {
         const user_times = await this.load_for_server<PersistedUserTimes>(
             server,
             METHOD_USER_TIMES_KEY,

src/hunt_optimizer/persistence/HuntOptimizerPersister.ts

@@ -6,7 +6,7 @@ import { WantedItemModel } from "../model";
 const WANTED_ITEMS_KEY = "HuntOptimizerStore.wantedItems";
 
 class HuntOptimizerPersister extends Persister {
-    persist_wanted_items(server: Server, wanted_items: WantedItemModel[]): void {
+    persist_wanted_items(server: Server, wanted_items: readonly WantedItemModel[]): void {
         this.persist_for_server(
             server,
             WANTED_ITEMS_KEY,

src/hunt_optimizer/stores/HuntOptimizerStore.ts

@@ -74,8 +74,8 @@ class HuntOptimizerStore implements Disposable {
     }
 
     private optimize = (
-        wanted_items: WantedItemModel[],
+        wanted_items: readonly WantedItemModel[],
-        methods: HuntMethodModel[],
+        methods: readonly HuntMethodModel[],
     ): OptimalResultModel | undefined => {
         if (!wanted_items.length) {
             return undefined;

src/quest_editor/gui/NpcCountsView.ts

@@ -37,7 +37,7 @@ export class NpcCountsView extends ResizableWidget {
         this.finalize_construction(NpcCountsView.prototype);
     }
 
-    private update_view(npcs: QuestNpcModel[]): void {
+    private update_view(npcs: readonly QuestNpcModel[]): void {
         const frag = document.createDocumentFragment();
 
         const npc_counts = new Map<NpcType, number>();

src/quest_editor/model/QuestModel.ts

@@ -17,58 +17,25 @@ import { entity_type_to_string } from "../../core/data_formats/parsing/quest/ent
 const logger = Logger.get("quest_editor/model/QuestModel");
 
 export class QuestModel {
-    readonly id: Property<number>;
+    private readonly _id: WritableProperty<number> = property(0);
+    private readonly _language: WritableProperty<number> = property(0);
+    private readonly _name: WritableProperty<string> = property("");
+    private readonly _short_description: WritableProperty<string> = property("");
+    private readonly _long_description: WritableProperty<string> = property("");
+    private readonly _map_designations: WritableProperty<Map<number, number>>;
+    private readonly _area_variants: WritableListProperty<AreaVariantModel> = list_property();
+    private readonly _objects: WritableListProperty<QuestObjectModel>;
+    private readonly _npcs: WritableListProperty<QuestNpcModel>;
 
-    set_id(id: number): this {
+    readonly id: Property<number> = this._id;
-        if (id < 0) throw new Error(`id should be greater than or equal to 0, was ${id}.`);
 
-        this._id.val = id;
+    readonly language: Property<number> = this._language;
-        return this;
-    }
 
-    readonly language: Property<number>;
+    readonly name: Property<string> = this._name;
 
-    set_language(language: number): this {
+    readonly short_description: Property<string> = this._short_description;
-        if (language < 0)
-            throw new Error(`language should be greater than or equal to 0, was ${language}.`);
 
-        this._language.val = language;
+    readonly long_description: Property<string> = this._long_description;
-        return this;
-    }
-
-    readonly name: Property<string>;
-
-    set_name(name: string): this {
-        if (name.length > 32)
-            throw new Error(`name can't be longer than 32 characters, got "${name}".`);
-
-        this._name.val = name;
-        return this;
-    }
-
-    readonly short_description: Property<string>;
-
-    set_short_description(short_description: string): this {
-        if (short_description.length > 128)
-            throw new Error(
-                `short_description can't be longer than 128 characters, got "${short_description}".`,
-            );
-
-        this._short_description.val = short_description;
-        return this;
-    }
-
-    readonly long_description: Property<string>;
-
-    set_long_description(long_description: string): this {
-        if (long_description.length > 288)
-            throw new Error(
-                `long_description can't be longer than 288 characters, got "${long_description}".`,
-            );
-
-        this._long_description.val = long_description;
-        return this;
-    }
 
     readonly episode: Episode;
 
@@ -82,15 +49,10 @@ export class QuestModel {
      */
     readonly map_designations: Property<Map<number, number>>;
 
-    set_map_designations(map_designations: Map<number, number>): this {
-        this._map_designations.val = map_designations;
-        return this;
-    }
-
     /**
      * One variant per area.
      */
-    readonly area_variants: ListProperty<AreaVariantModel>;
+    readonly area_variants: ListProperty<AreaVariantModel> = this._area_variants;
 
     readonly objects: ListProperty<QuestObjectModel>;
 
@@ -105,16 +67,6 @@ export class QuestModel {
 
     readonly shop_items: number[];
 
-    private readonly _id: WritableProperty<number> = property(0);
-    private readonly _language: WritableProperty<number> = property(0);
-    private readonly _name: WritableProperty<string> = property("");
-    private readonly _short_description: WritableProperty<string> = property("");
-    private readonly _long_description: WritableProperty<string> = property("");
-    private readonly _map_designations: WritableProperty<Map<number, number>>;
-    private readonly _area_variants: WritableListProperty<AreaVariantModel> = list_property();
-    private readonly _objects: WritableListProperty<QuestObjectModel>;
-    private readonly _npcs: WritableListProperty<QuestNpcModel>;
-
     constructor(
         id: number,
         language: number,
@@ -137,13 +89,6 @@ export class QuestModel {
         if (!Array.isArray(object_code)) throw new Error("object_code is required.");
         if (!Array.isArray(shop_items)) throw new Error("shop_items is required.");
 
-        this.id = this._id;
-        this.language = this._language;
-        this.name = this._name;
-        this.short_description = this._short_description;
-        this.long_description = this._long_description;
-        this.area_variants = this._area_variants;
-
         this.set_id(id);
         this.set_language(language);
         this.set_name(name);
@@ -182,6 +127,54 @@ export class QuestModel {
         this.map_designations.observe(this.update_area_variants);
     }
 
+    set_id(id: number): this {
+        if (id < 0) throw new Error(`id should be greater than or equal to 0, was ${id}.`);
+
+        this._id.val = id;
+        return this;
+    }
+
+    set_language(language: number): this {
+        if (language < 0)
+            throw new Error(`language should be greater than or equal to 0, was ${language}.`);
+
+        this._language.val = language;
+        return this;
+    }
+
+    set_name(name: string): this {
+        if (name.length > 32)
+            throw new Error(`name can't be longer than 32 characters, got "${name}".`);
+
+        this._name.val = name;
+        return this;
+    }
+
+    set_short_description(short_description: string): this {
+        if (short_description.length > 128)
+            throw new Error(
+                `short_description can't be longer than 128 characters, got "${short_description}".`,
+            );
+
+        this._short_description.val = short_description;
+        return this;
+    }
+
+    set_long_description(long_description: string): this {
+        if (long_description.length > 288)
+            throw new Error(
+                `long_description can't be longer than 288 characters, got "${long_description}".`,
+            );
+
+        this._long_description.val = long_description;
+        return this;
+    }
+
+    set_map_designations(map_designations: Map<number, number>): this {
+        this._map_designations.val = map_designations;
+        return this;
+    }
+
     add_entity(entity: QuestEntityModel): void {
         if (entity instanceof QuestObjectModel) {
             this.add_object(entity);

src/quest_editor/rendering/QuestModelManager.ts

@@ -237,7 +237,7 @@ class EntityModelManager {
         }
     }
 
-    remove(entities: QuestEntityModel[]): void {
+    remove(entities: readonly QuestEntityModel[]): void {
         for (const entity of entities) {
             const queue_index = this.queue.indexOf(entity);