ISpliceable.splice should take a readonly array of values (microsoft#166751)

Calling `.splice` should not modify the array of values passed in

Author: mjbvz

src/vs/base/browser/ui/list/listView.ts

@@ -467,7 +467,7 @@ export class ListView<T> implements ISpliceable<T>, IDisposable {
 		}
 	}
 
-	splice(start: number, deleteCount: number, elements: T[] = []): T[] {
+	splice(start: number, deleteCount: number, elements: readonly T[] = []): T[] {
 		if (this.splicing) {
 			throw new Error('Can\'t run recursive splices.');
 		}
@@ -482,7 +482,7 @@ export class ListView<T> implements ISpliceable<T>, IDisposable {
 		}
 	}
 
-	private _splice(start: number, deleteCount: number, elements: T[] = []): T[] {
+	private _splice(start: number, deleteCount: number, elements: readonly T[] = []): T[] {
 		const previousRenderRange = this.getRenderRange(this.lastRenderTop, this.lastRenderHeight);
 		const deleteRange = { start, end: start + deleteCount };
 		const removeRange = Range.intersect(previousRenderRange, deleteRange);

src/vs/base/browser/ui/list/listWidget.ts

@@ -1426,7 +1426,7 @@ export class List<T> implements ISpliceable<T>, IThemable, IDisposable {
 		return this._options;
 	}
 
-	splice(start: number, deleteCount: number, elements: T[] = []): void {
+	splice(start: number, deleteCount: number, elements: readonly T[] = []): void {
 		if (start < 0 || start > this.view.length) {
 			throw new ListError(this.user, `Invalid start index: ${start}`);
 		}

src/vs/base/browser/ui/table/tableWidget.ts

@@ -228,7 +228,7 @@ export class Table<TRow> implements ISpliceable<TRow>, IThemable, IDisposable {
 		this.list.updateOptions(options);
 	}
 
-	splice(start: number, deleteCount: number, elements: TRow[] = []): void {
+	splice(start: number, deleteCount: number, elements: readonly TRow[] = []): void {
 		this.list.splice(start, deleteCount, elements);
 	}
 

src/vs/base/browser/ui/tree/abstractTree.ts

@@ -1317,7 +1317,7 @@ class TreeNodeList<T, TFilterData, TRef> extends List<ITreeNode<T, TFilterData>>
 		return new TreeNodeListMouseController(this, options.tree);
 	}
 
-	override splice(start: number, deleteCount: number, elements: ITreeNode<T, TFilterData>[] = []): void {
+	override splice(start: number, deleteCount: number, elements: readonly ITreeNode<T, TFilterData>[] = []): void {
 		super.splice(start, deleteCount, elements);
 
 		if (elements.length === 0) {

src/vs/base/common/arrays.ts

@@ -178,6 +178,7 @@ export function groupBy<T>(data: ReadonlyArray<T>, compare: (a: T, b: T) => numb
 }
 
 interface IMutableSplice<T> extends ISplice<T> {
+	readonly toInsert: T[];
 	deleteCount: number;
 }
 

src/vs/base/common/sequence.ts

@@ -8,11 +8,11 @@ import { Emitter, Event } from 'vs/base/common/event';
 export interface ISplice<T> {
 	readonly start: number;
 	readonly deleteCount: number;
-	readonly toInsert: T[];
+	readonly toInsert: readonly T[];
 }
 
 export interface ISpliceable<T> {
-	splice(start: number, deleteCount: number, toInsert: T[]): void;
+	splice(start: number, deleteCount: number, toInsert: readonly T[]): void;
 }
 
 export interface ISequence<T> {
@@ -27,7 +27,7 @@ export class Sequence<T> implements ISequence<T>, ISpliceable<T> {
 	private readonly _onDidSplice = new Emitter<ISplice<T>>();
 	readonly onDidSplice: Event<ISplice<T>> = this._onDidSplice.event;
 
-	splice(start: number, deleteCount: number, toInsert: T[] = []): void {
+	splice(start: number, deleteCount: number, toInsert: readonly T[] = []): void {
 		this.elements.splice(start, deleteCount, ...toInsert);
 		this._onDidSplice.fire({ start, deleteCount, toInsert });
 	}

src/vs/workbench/contrib/notebook/browser/view/notebookCellList.ts

@@ -481,7 +481,7 @@ export class NotebookCellList extends WorkbenchList<CellViewModel> implements ID
 		this._updateElementsInWebview(viewDiffs);
 	}
 
-	splice2(start: number, deleteCount: number, elements: CellViewModel[] = []): void {
+	splice2(start: number, deleteCount: number, elements: readonly CellViewModel[] = []): void {
 		// we need to convert start and delete count based on hidden ranges
 		if (start < 0 || start > this.view.length) {
 			return;

src/vs/workbench/contrib/notebook/common/notebookCommon.ts

@@ -697,6 +697,7 @@ export class MimeTypeDisplayOrder {
 }
 
 interface IMutableSplice<T> extends ISplice<T> {
+	readonly toInsert: T[];
 	deleteCount: number;
 }