Enable @typescript-eslint/explicit-function-return-type in /src (#9788)

* Enable `@typescript-eslint/explicit-member-accessibility` on /src

* Prettier

* Enable `@typescript-eslint/explicit-function-return-type` in /src

* Fix types

* tsc strict fixes

* Delint

* Fix test

* Fix bad merge

src/resizer/distributors/collapse.ts

@@ -26,14 +26,14 @@ export interface ICollapseConfig extends IConfig {
 }
 
 class CollapseItem extends ResizeItem<ICollapseConfig> {
-    public notifyCollapsed(collapsed: boolean) {
+    public notifyCollapsed(collapsed: boolean): void {
         const callback = this.resizer.config.onCollapsed;
         if (callback) {
             callback(collapsed, this.id, this.domNode);
         }
     }
 
-    public get isCollapsed() {
+    public get isCollapsed(): boolean {
         const isItemCollapsed = this.resizer.config.isItemCollapsed;
         return isItemCollapsed(this.domNode);
     }
@@ -58,7 +58,7 @@ export default class CollapseDistributor extends FixedDistributor<ICollapseConfi
         this.isCollapsed = item.isCollapsed;
     }
 
-    public resize(newSize: number) {
+    public resize(newSize: number): void {
         const isCollapsedSize = newSize < this.toggleSize;
         if (isCollapsedSize !== this.isCollapsed) {
             this.isCollapsed = isCollapsedSize;

src/resizer/distributors/fixed.ts

@@ -43,7 +43,7 @@ export default class FixedDistributor<C extends IConfig, I extends ResizeItem<an
         this.beforeOffset = item.offset();
     }
 
-    public get size() {
+    public get size(): string {
         return this.item.getSize();
     }
 
@@ -51,19 +51,19 @@ export default class FixedDistributor<C extends IConfig, I extends ResizeItem<an
         this.item.setRawSize(size);
     }
 
-    public resize(size: number) {
+    public resize(size: number): void {
         this.item.setSize(size);
     }
 
-    public resizeFromContainerOffset(offset: number) {
+    public resizeFromContainerOffset(offset: number): void {
         this.resize(offset - this.beforeOffset);
     }
 
-    public start() {
+    public start(): void {
         this.item.start();
     }
 
-    public finish() {
+    public finish(): void {
         this.item.finish();
     }
 }

src/resizer/distributors/percentage.ts

@@ -19,7 +19,7 @@ import FixedDistributor from "./fixed";
 import { IConfig } from "../resizer";
 
 class PercentageSizer extends Sizer {
-    public start(item: HTMLElement) {
+    public start(item: HTMLElement): void {
         if (this.vertical) {
             item.style.minHeight = null;
         } else {
@@ -27,7 +27,7 @@ class PercentageSizer extends Sizer {
         }
     }
 
-    public finish(item: HTMLElement) {
+    public finish(item: HTMLElement): void {
         const parent = item.offsetParent as HTMLElement;
         if (!parent) return;
         if (this.vertical) {
@@ -43,7 +43,7 @@ class PercentageSizer extends Sizer {
 }
 
 export default class PercentageDistributor extends FixedDistributor<IConfig> {
-    public static createSizer(containerElement: HTMLElement, vertical: boolean, reverse: boolean) {
+    public static createSizer(containerElement: HTMLElement, vertical: boolean, reverse: boolean): PercentageSizer {
         return new PercentageSizer(containerElement, vertical, reverse);
     }
 }

src/resizer/item.ts

@@ -37,12 +37,12 @@ export default class ResizeItem<C extends IConfig = IConfig> {
         this.id = handle.getAttribute("data-id");
     }
 
-    private copyWith(handle: HTMLElement, resizer: Resizer, sizer: Sizer, container?: HTMLElement) {
+    private copyWith(handle: HTMLElement, resizer: Resizer, sizer: Sizer, container?: HTMLElement): ResizeItem {
         const Ctor = this.constructor as typeof ResizeItem;
         return new Ctor(handle, resizer, sizer, container);
     }
 
-    private advance(forwards: boolean) {
+    private advance(forwards: boolean): ResizeItem {
         // opposite direction from fromResizeHandle to get back to handle
         let handle = this.reverse ? this.domNode.previousElementSibling : this.domNode.nextElementSibling;
         const moveNext = forwards !== this.reverse; // xor
@@ -62,39 +62,39 @@ export default class ResizeItem<C extends IConfig = IConfig> {
         }
     }
 
-    public next() {
+    public next(): ResizeItem {
         return this.advance(true);
     }
 
-    public previous() {
+    public previous(): ResizeItem {
         return this.advance(false);
     }
 
-    public size() {
+    public size(): number {
         return this.sizer.getItemSize(this.domNode);
     }
 
-    public offset() {
+    public offset(): number {
         return this.sizer.getItemOffset(this.domNode);
     }
 
-    public start() {
+    public start(): void {
         this.sizer.start(this.domNode);
     }
 
-    public finish() {
+    public finish(): void {
         this.sizer.finish(this.domNode);
     }
 
-    public getSize() {
+    public getSize(): string {
         return this.sizer.getDesiredItemSize(this.domNode);
     }
 
-    public setRawSize(size: string) {
+    public setRawSize(size: string): void {
         this.sizer.setItemSize(this.domNode, size);
     }
 
-    public setSize(size: number) {
+    public setSize(size: number): void {
         this.setRawSize(`${Math.round(size)}px`);
         const callback = this.resizer.config.onResized;
         if (callback) {
@@ -102,7 +102,7 @@ export default class ResizeItem<C extends IConfig = IConfig> {
         }
     }
 
-    public clearSize() {
+    public clearSize(): void {
         this.sizer.clearItemSize(this.domNode);
         const callback = this.resizer.config.onResized;
         if (callback) {
@@ -110,7 +110,7 @@ export default class ResizeItem<C extends IConfig = IConfig> {
         }
     }
 
-    public first() {
+    public first(): ResizeItem {
         const firstHandle = Array.from(this.domNode.parentElement.children).find((el) => {
             return this.resizer.isResizeHandle(<HTMLElement>el);
         });
@@ -119,7 +119,7 @@ export default class ResizeItem<C extends IConfig = IConfig> {
         }
     }
 
-    public last() {
+    public last(): ResizeItem {
         const lastHandle = Array.from(this.domNode.parentElement.children)
             .reverse()
             .find((el) => {

src/resizer/resizer.ts

@@ -65,17 +65,17 @@ export default class Resizer<C extends IConfig = IConfig> {
         };
     }
 
-    public setClassNames(classNames: IClassNames) {
+    public setClassNames(classNames: IClassNames): void {
         this.classNames = classNames;
     }
 
-    public attach() {
+    public attach(): void {
         const attachment = this?.config?.handler?.parentElement ?? this.container;
         attachment.addEventListener("mousedown", this.onMouseDown, false);
         window.addEventListener("resize", this.onResize);
     }
 
-    public detach() {
+    public detach(): void {
         const attachment = this?.config?.handler?.parentElement ?? this.container;
         attachment.removeEventListener("mousedown", this.onMouseDown, false);
         window.removeEventListener("resize", this.onResize);
@@ -113,7 +113,7 @@ export default class Resizer<C extends IConfig = IConfig> {
         return el && el.classList.contains(this.classNames.handle);
     }
 
-    private onMouseDown = (event: MouseEvent) => {
+    private onMouseDown = (event: MouseEvent): void => {
         // use closest in case the resize handle contains
         // child dom nodes that can be the target
         const resizeHandle = event.target && (<HTMLDivElement>event.target).closest(`.${this.classNames.handle}`);
@@ -143,13 +143,13 @@ export default class Resizer<C extends IConfig = IConfig> {
         const { sizer, distributor } = this.createSizerAndDistributor(<HTMLDivElement>resizeHandle);
         distributor.start();
 
-        const onMouseMove = (event) => {
+        const onMouseMove = (event: MouseEvent): void => {
             const offset = sizer.offsetFromEvent(event);
             distributor.resizeFromContainerOffset(offset);
         };
 
         const body = document.body;
-        const finishResize = () => {
+        const finishResize = (): void => {
             if (this.classNames.resizing) {
                 this.container?.classList?.remove(this.classNames.resizing);
             }
@@ -178,7 +178,7 @@ export default class Resizer<C extends IConfig = IConfig> {
         { trailing: true, leading: true },
     );
 
-    public getDistributors = () => {
+    public getDistributors = (): FixedDistributor<any, ResizeItem<any>>[] => {
         return this.getResizeHandles().map((handle) => {
             const { distributor } = this.createSizerAndDistributor(<HTMLDivElement>handle);
             return distributor;

src/resizer/sizer.ts

@@ -68,7 +68,7 @@ export default class Sizer {
         return offset;
     }
 
-    public getDesiredItemSize(item: HTMLElement) {
+    public getDesiredItemSize(item: HTMLElement): string {
         if (this.vertical) {
             return item.style.height;
         } else {
@@ -76,7 +76,7 @@ export default class Sizer {
         }
     }
 
-    public setItemSize(item: HTMLElement, size: string) {
+    public setItemSize(item: HTMLElement, size: string): void {
         if (this.vertical) {
             item.style.height = size;
         } else {
@@ -84,7 +84,7 @@ export default class Sizer {
         }
     }
 
-    public clearItemSize(item: HTMLElement) {
+    public clearItemSize(item: HTMLElement): void {
         if (this.vertical) {
             item.style.height = null;
         } else {
@@ -92,16 +92,16 @@ export default class Sizer {
         }
     }
 
-    public start(item: HTMLElement) {}
+    public start(item: HTMLElement): void {}
 
-    public finish(item: HTMLElement) {}
+    public finish(item: HTMLElement): void {}
 
     /**
         @param {MouseEvent} event the mouse event
         @return {number} the distance between the cursor and the edge of the container,
             along the applicable axis (vertical or horizontal)
     */
-    public offsetFromEvent(event: MouseEvent) {
+    public offsetFromEvent(event: MouseEvent): number {
         const pos = this.vertical ? event.pageY : event.pageX;
         if (this.reverse) {
             return this.getPageOffset() + this.getTotalSize() - pos;