feat: add rule creators for saving and reading api definition

npm/ng-packs/packages/schematics/src/utils/source.ts

@@ -1,12 +1,12 @@
 import { SchematicsException, Tree } from '@angular-devkit/schematics';
 import got from 'got';
 import { Exception } from '../enums';
-import { Project } from '../models';
+import { ApiDefinition, Project } from '../models';
 import { getAssignedPropertyFromObjectliteral } from './ast';
 import { interpolate } from './common';
 import { readEnvironment } from './workspace';
 
-export async function getSourceJson(url: string) {
+export async function getApiDefinition(url: string) {
   let body: any;
 
   try {
@@ -45,3 +45,24 @@ export function getSourceUrl(tree: Tree, project: Project, moduleName: string) {
 
   return assignment.replace(/[`'"]/g, '');
 }
+
+export function createApiDefinitionReader(targetPath: string) {
+  return (tree: Tree) => {
+    try {
+      const buffer = tree.read(targetPath);
+      const apiDefinition: ApiDefinition = JSON.parse(buffer!.toString());
+      return apiDefinition;
+    } catch (_) {}
+
+    throw new SchematicsException(interpolate(Exception.NoApiDefinition, targetPath));
+  };
+}
+
+export function createApiDefinitionSaver(apiDefinition: ApiDefinition, targetPath: string) {
+  return (tree: Tree) => {
+    tree[tree.exists(targetPath) ? 'overwrite' : 'create'](
+      targetPath,
+      JSON.stringify(apiDefinition, null, 2),
+    );
+  };
+}