Updated the files.

my-app/node_modules/@angular-devkit/schematics/src/utility/update-buffer.d.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import { BaseException } from '@angular-devkit/core';
+import MagicString from 'magic-string';
+export declare class IndexOutOfBoundException extends BaseException {
+    constructor(index: number, min: number, max?: number);
+}
+/**
+ * Base class for an update buffer implementation that allows buffers to be inserted to the _right
+ * or _left, or deleted, while keeping indices to the original buffer.
+ */
+export declare abstract class UpdateBufferBase {
+    protected _originalContent: Buffer;
+    constructor(_originalContent: Buffer);
+    abstract get length(): number;
+    abstract get original(): Buffer;
+    abstract toString(encoding?: string): string;
+    abstract generate(): Buffer;
+    abstract insertLeft(index: number, content: Buffer, assert?: boolean): void;
+    abstract insertRight(index: number, content: Buffer, assert?: boolean): void;
+    abstract remove(index: number, length: number): void;
+    /**
+     * Creates an UpdateBufferBase instance.
+     *
+     * @param contentPath The path of the update buffer instance.
+     * @param originalContent The original content of the update buffer instance.
+     * @returns An UpdateBufferBase instance.
+     */
+    static create(contentPath: string, originalContent: Buffer): UpdateBufferBase;
+}
+/**
+ * An utility class that allows buffers to be inserted to the _right or _left, or deleted, while
+ * keeping indices to the original buffer.
+ */
+export declare class UpdateBuffer extends UpdateBufferBase {
+    protected _mutatableContent: MagicString;
+    protected _assertIndex(index: number): void;
+    get length(): number;
+    get original(): Buffer;
+    toString(): string;
+    generate(): Buffer;
+    insertLeft(index: number, content: Buffer): void;
+    insertRight(index: number, content: Buffer): void;
+    remove(index: number, length: number): void;
+}

my-app/node_modules/@angular-devkit/schematics/src/utility/update-buffer.js

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+"use strict";
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.UpdateBuffer = exports.UpdateBufferBase = exports.IndexOutOfBoundException = void 0;
+const core_1 = require("@angular-devkit/core");
+const magic_string_1 = __importDefault(require("magic-string"));
+const node_util_1 = require("node:util");
+class IndexOutOfBoundException extends core_1.BaseException {
+    constructor(index, min, max = Infinity) {
+        super(`Index ${index} outside of range [${min}, ${max}].`);
+    }
+}
+exports.IndexOutOfBoundException = IndexOutOfBoundException;
+/**
+ * Base class for an update buffer implementation that allows buffers to be inserted to the _right
+ * or _left, or deleted, while keeping indices to the original buffer.
+ */
+class UpdateBufferBase {
+    _originalContent;
+    constructor(_originalContent) {
+        this._originalContent = _originalContent;
+    }
+    /**
+     * Creates an UpdateBufferBase instance.
+     *
+     * @param contentPath The path of the update buffer instance.
+     * @param originalContent The original content of the update buffer instance.
+     * @returns An UpdateBufferBase instance.
+     */
+    static create(contentPath, originalContent) {
+        try {
+            // We only support utf8 encoding.
+            new node_util_1.TextDecoder('utf8', { fatal: true }).decode(originalContent);
+            return new UpdateBuffer(originalContent);
+        }
+        catch (e) {
+            if (e instanceof TypeError) {
+                throw new Error(`Failed to decode "${contentPath}" as UTF-8 text.`);
+            }
+            throw e;
+        }
+    }
+}
+exports.UpdateBufferBase = UpdateBufferBase;
+/**
+ * An utility class that allows buffers to be inserted to the _right or _left, or deleted, while
+ * keeping indices to the original buffer.
+ */
+class UpdateBuffer extends UpdateBufferBase {
+    _mutatableContent = new magic_string_1.default(this._originalContent.toString());
+    _assertIndex(index) {
+        if (index < 0 || index > this._originalContent.length) {
+            throw new IndexOutOfBoundException(index, 0, this._originalContent.length);
+        }
+    }
+    get length() {
+        return this._mutatableContent.length();
+    }
+    get original() {
+        return this._originalContent;
+    }
+    toString() {
+        return this._mutatableContent.toString();
+    }
+    generate() {
+        return Buffer.from(this.toString());
+    }
+    insertLeft(index, content) {
+        this._assertIndex(index);
+        this._mutatableContent.appendLeft(index, content.toString());
+    }
+    insertRight(index, content) {
+        this._assertIndex(index);
+        this._mutatableContent.appendRight(index, content.toString());
+    }
+    remove(index, length) {
+        this._assertIndex(index);
+        this._mutatableContent.remove(index, index + length);
+    }
+}
+exports.UpdateBuffer = UpdateBuffer;