update.ts

import {
  Rule,
  SchematicContext,
  Tree,
  SchematicsException,
} from '@angular-devkit/schematics';

export function updatePackage(name: string): Rule {
  return (tree: Tree, context: SchematicContext) => {
    const pkgPath = '/package.json';
    const buffer = tree.read(pkgPath);
    if (buffer === null) {
      throw new SchematicsException('Could not read package.json');
    }
    const content = buffer.toString();
    const pkg = JSON.parse(content);

    if (pkg === null || typeof pkg !== 'object' || Array.isArray(pkg)) {
      throw new SchematicsException('Error reading package.json');
    }

    const dependencyCategories = ['dependencies', 'devDependencies'];

    dependencyCategories.forEach((category) => {
      const packageName = `@ngrx/${name}`;

      if (pkg[category] && pkg[category][packageName]) {
        const firstChar = pkg[category][packageName][0];
        const suffix = match(firstChar, '^') || match(firstChar, '~');

        pkg[category][packageName] = `${suffix}6.0.0`;
      }
    });

    tree.overwrite(pkgPath, JSON.stringify(pkg, null, 2));

    return tree;
  };
}

function match(value: string, test: string) {
  return value === test ? test : '';
}