feat: support optional result props (#4)

* feat: support optional result props

* fix: update return types

* refactor: reorganize files

* fix: process wait requests

src/chargebee-resource.class.ts

@@ -0,0 +1,91 @@
+import type { ChargeBee } from "chargebee-typescript";
+
+import type { RequestWrapper } from "chargebee-typescript/lib/request_wrapper";
+import type { ListResult } from "chargebee-typescript/lib/list_result";
+import type { Result } from "chargebee-typescript/lib/result";
+
+import type {
+  ResourceResult,
+  ResultMethodName,
+  ProcessWaitMethodName,
+  ListResultMethodName,
+  ResolveResultReturn,
+} from "./chargebee-resource.types";
+
+export class ChargebeeResource {
+  constructor(protected readonly chargebee: ChargeBee) {}
+
+  protected request<
+    TResourceName extends keyof ChargeBee,
+    TMethodName extends keyof ChargeBee[TResourceName],
+    TReturning extends ResourceResult,
+  >(
+    resourceName: TResourceName,
+    methodName: TMethodName extends
+      | ResultMethodName<TResourceName, TMethodName>
+      | ProcessWaitMethodName<TResourceName, TMethodName>
+      ? TMethodName
+      : never,
+    returning: TReturning,
+  ) {
+    type MethodDefinition = ChargeBee[TResourceName][TMethodName] extends (
+      ...args: unknown[]
+    ) => RequestWrapper<Result>
+      ? ChargeBee[TResourceName][TMethodName]
+      : never;
+
+    const functionDef = this.chargebee[resourceName][
+      methodName
+    ] as MethodDefinition;
+
+    return async (...args: Parameters<MethodDefinition>) => {
+      return functionDef(...args)
+        .request()
+        .then(this.resolveResult(returning));
+    };
+  }
+
+  protected listRequest<
+    TResourceName extends keyof ChargeBee,
+    TMethodName extends keyof ChargeBee[TResourceName],
+    TReturning extends ResourceResult,
+  >(
+    resourceName: TResourceName,
+    methodName: TMethodName extends ListResultMethodName<
+      TResourceName,
+      TMethodName
+    >
+      ? TMethodName
+      : never,
+    returning: TReturning,
+  ) {
+    type MethodDefinition = ChargeBee[TResourceName][TMethodName] extends (
+      ...args: unknown[]
+    ) => RequestWrapper<ListResult>
+      ? ChargeBee[TResourceName][TMethodName]
+      : never;
+
+    const functionDef = this.chargebee[resourceName][
+      methodName
+    ] as MethodDefinition;
+
+    return async (...args: Parameters<MethodDefinition>) => {
+      return functionDef(...args)
+        .request()
+        .then((listResult) => {
+          const items = listResult.list.map(this.resolveResult(returning));
+          return {
+            items,
+            nextOffset: listResult.next_offset as string | undefined,
+          };
+        });
+    };
+  }
+
+  private resolveResult =
+    <TReturning extends ResourceResult>(returning: TReturning) =>
+    (result: Result) =>
+      Object.fromEntries(
+        Object.keys(returning).map((key) => [key, result[key as keyof Result]]),
+      ) as ResolveResultReturn<TReturning>;
+}

src/chargebee-resource.types.ts

@@ -0,0 +1,49 @@
+import type { ChargeBee } from "chargebee-typescript";
+
+import type { RequestWrapper } from "chargebee-typescript/lib/request_wrapper";
+import type { ListResult } from "chargebee-typescript/lib/list_result";
+import type { Result } from "chargebee-typescript/lib/result";
+import type { ProcessWait } from "chargebee-typescript/lib/process_wait";
+
+export type ResultMethodName<
+  TResource extends keyof ChargeBee,
+  TMethod extends keyof ChargeBee[TResource],
+> = ChargeBee[TResource][TMethod] extends (
+  ...args: unknown[]
+) => RequestWrapper<infer R>
+  ? R extends Result
+    ? TMethod
+    : "Method must return a RequestWrapper<Result>"
+  : never;
+
+export type ListResultMethodName<
+  TResource extends keyof ChargeBee,
+  TMethod extends keyof ChargeBee[TResource],
+> = ChargeBee[TResource][TMethod] extends (
+  ...args: unknown[]
+) => RequestWrapper<infer R>
+  ? R extends ListResult
+    ? TMethod
+    : "Method must return a RequestWrapper<ListResult>"
+  : never;
+
+export type ProcessWaitMethodName<
+  TResource extends keyof ChargeBee,
+  TMethod extends keyof ChargeBee[TResource],
+> = ChargeBee[TResource][TMethod] extends (...args: unknown[]) => ProcessWait
+  ? TMethod
+  : "Method must return a ProcessWait";
+
+export type ResourceResult = {
+  [K in keyof Result]?: {
+    optional: boolean;
+  };
+};
+
+export type ResolveResultReturn<T extends ResourceResult> = {
+  [K in keyof T]: K extends keyof Result
+    ? T[K] extends { optional: true }
+      ? Result[K] | undefined
+      : Result[K]
+    : never;
+};

src/chargebee.module.ts

@@ -1,12 +1,11 @@
 import { Global, Module } from "@nestjs/common";
 
 import { ConfigurableModuleClass } from "./chargebee.module-definition";
-import { ChargebeeClientService } from "./chargebee-client.service";
 import { ChargebeeService } from "./chargebee.service";
 
 @Global()
 @Module({
-  providers: [ChargebeeClientService, ChargebeeService],
+  providers: [ChargebeeService],
   exports: [ChargebeeService],
 })
 export class ChargebeeModule extends ConfigurableModuleClass {}

src/chargebee.service.ts

@@ -1,11 +1,27 @@
-import { Injectable } from "@nestjs/common";
+import { Inject, Injectable, Optional } from "@nestjs/common";
+import { ChargeBee } from "chargebee-typescript";
 
-import { ChargebeeClientService } from "./chargebee-client.service";
+import { ChargebeeModuleOptions } from "./chargebee.interface";
+import { CHARGEBEE_MODULE_OPTIONS_TOKEN } from "./chargebee.module-definition";
 import { ChargebeeResourceWrapper } from "./chargebee-resource-wrapper.class";
 
 @Injectable()
 export class ChargebeeService extends ChargebeeResourceWrapper {
-  constructor(chargebeeClient: ChargebeeClientService) {
-    super(chargebeeClient.client);
+  constructor(
+    @Inject(CHARGEBEE_MODULE_OPTIONS_TOKEN)
+    options: ChargebeeModuleOptions,
+    @Optional()
+    client = configureChargebee(options),
+  ) {
+    super(client);
   }
 }
+
+function configureChargebee(options: ChargebeeModuleOptions) {
+  const client = new ChargeBee();
+  client.configure({
+    site: options.site,
+    api_key: options.apiKey,
+  });
+  return client;
+}