Angular Schematics - Apply thousands of changes on tree cause error "Maximum call stack size exceeded"

# 🐞 Bug report

### Description

I use Angular Schematics to migrate from AngularJs to Angular. The application is a large one with thousands of page. I try to create a component for each page based on a template. When I try to create the component on a smaller project like 200 pages it's working but when I fall on a large one with more than 1000 pages (1000 schematics rules)

## 🔬 Minimal Reproduction

export function createPageComponents(options: any): Rule {

    return (tree: Tree, context: SchematicContext) => {

        const logger = context.logger;

        const directory = tree.getDir('my_path/pages');


        const rules: Rule[] = [];

        directory.visit((filePath) => {

            if (!filePath.endsWith('config.ts')) {

                return;

            }

            const dirPath = dirname(filePath);

            const parsedPath = parseName(dirPath, basename(filePath).split('.')[0]);

            options = {

                path: parsedPath.path,

                name: parsedPath.name

            };

            const templateSource = apply(

                url('./files'),

                [

                    applyTemplates({

                        ...strings,

                        ...options

                    }),

                    move(parsedPath.path)

                ]

            );

            const rule = mergeWith(templateSource);

            rules.push(rule);

        });

        return chain(rules);

    };

}

## 🔥 Exception or Error

    RangeError: Maximum call stack size exceeded

        at Console.warn ()

        at Observable._trySubscribe (my_path\node_modules\rxjs\internal\Observable.js:55:25)

        at Observable.subscribe (my_path\node_modules\rxjs\internal\Observable.js:30:22)

        at MergeMapOperator.call (my_path\node_modules\rxjs\internal\operators\mergeMap.js:39:23)

        at Observable.subscribe (my_path\node_modules\rxjs\internal\Observable.js:25:31)

        at MapOperator.call (my_path\node_modules\rxjs\internal\operators\map.js:32:23)

        at Observable.subscribe (my_path\node_modules\rxjs\internal\Observable.js:25:31)

        at MapToOperator.call (my_path\node_modules\rxjs\internal\operators\mapTo.js:26:23)

        at Observable.subscribe (my_path\node_modules\rxjs\internal\Observable.js:25:31)

        at DefaultIfEmptyOperator.call (my_path\node_modules\rxjs\internal\operators\defaultIfEmpty.js:27:23)

## 🌍 Your Environment

Angular CLI: 9.1.4

Node: 10.19.0

OS: win32 x64


Angular: 9.1.4

... animations, cli, common, compiler, compiler-cli, core, forms

... language-service, platform-browser, platform-browser-dynamic

... router

Ivy Workspace: Yes

Package                            Version

------------------------------------------------------------

@angular-devkit/architect          0.901.4

@angular-devkit/build-angular      0.901.4

@angular-devkit/build-ng-packagr   0.901.4

@angular-devkit/build-optimizer    0.901.4

@angular-devkit/build-webpack      0.901.4

@angular-devkit/core               9.1.4

@angular-devkit/schematics         9.1.7

@angular-devkit/schematics-cli     0.901.7

@angular/upgrade                   9.1.9

@ngtools/webpack                   9.1.4

@schematics/angular                9.1.4 (cli-only)

@schematics/schematics             0.901.7

@schematics/update                 0.901.4

ng-packagr                         9.1.3

rxjs                               6.5.5

typescript                         3.8.3

webpack                            4.42.0

Comienza en el punto de entrada createPageComponents de la reproducción, especialmente en el array rules y chain(rules), y reproduce el fallo con más de 1.000 reglas de Schematics. Lee la ruta de ejecución de Angular Schematics junto con el stack trace de RxJS mostrado en el informe. Se considera terminado cuando se puede aplicar el gran conjunto de cambios de componentes de página sin un error de maximum call stack.

Escrito por el modelo de indexación a partir del texto del issue.