fix(@schematics/angular): retain existing EOL when updating JSON files

This commit updates the JSON utility to retain the existing EOF when updating files.

Author: alan-agius4

packages/schematics/angular/utility/eol.ts

@@ -0,0 +1,25 @@
+/**
+ * @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 { EOL } from 'node:os';
+
+const CRLF = '\r\n';
+const LF = '\n';
+
+export function getEOL(content: string): string {
+  const newlines = content.match(/(?:\r?\n)/g);
+
+  if (newlines?.length) {
+    const crlf = newlines.filter((l) => l === CRLF).length;
+    const lf = newlines.length - crlf;
+
+    return crlf > lf ? CRLF : LF;
+  }
+
+  return EOL;
+}

packages/schematics/angular/utility/json-file.ts

@@ -18,16 +18,22 @@ import {
   parseTree,
   printParseErrorCode,
 } from 'jsonc-parser';
+import { getEOL } from './eol';
 
 export type InsertionIndex = (properties: string[]) => number;
 export type JSONPath = (string | number)[];
 
 /** @private */
 export class JSONFile {
   content: string;
+  private eol: string;
 
-  constructor(private readonly host: Tree, private readonly path: string) {
+  constructor(
+    private readonly host: Tree,
+    private readonly path: string,
+  ) {
     this.content = this.host.readText(this.path);
+    this.eol = getEOL(this.content);
   }
 
   private _jsonAst: Node | undefined;
@@ -81,7 +87,9 @@ export class JSONFile {
 
     const edits = modify(this.content, jsonPath, value, {
       getInsertionIndex,
+
       formattingOptions: {
+        eol: this.eol,
         insertSpaces: true,
         tabSize: 2,
       },