IHttpRequestHandler: 公式 HttpCalloutMock のやりづらさと ApexTools の答え

// ❌ 階層が深いほど破綻する
String body = '{"records":[{"Id":"001xx","Name":"Acme","Contacts":{"totalSize":2}}]}';

// ❌ エンドポイントが増えるたびに分岐が伸びる
public HttpResponse respond(HttpRequest req) {
  if(req.getEndpoint().contains('/accounts')) { ... }
  else if(req.getEndpoint().contains('/contacts')) { ... }
  ...
}

MockResponse.of('GET').respond('{"message":"not found"}', 404)          // String
MockResponse.of('post').respond(new Map<String, Object>{ ... }, 200)    // Map / List は JSON 化。メソッド名は大小どちらでも
MockResponse.of('GET').respond(imageBytes, 200).header('Content-Type', 'image/jpeg')  // Blob + ヘッダ
MockResponse.of('GET').respond(ok, 200).repeat()                        // キュー末尾に置くと以降ずっとこれ

MockHttpRequestHandler mock = new MockHttpRequestHandler(new List<MockResponse>{
  MockResponse.of('GET').respond(notFound, 404),    // 1 手目: 存在確認
  MockResponse.of('POST').respond(created, 201),    // 2 手目: 作成
  MockResponse.of('GET').respond(found, 200)        // 3 手目: 再取得
});

// 1 回目 500、2 回目 500、3 回目に成功。モック側にカウンタは不要
new List<MockResponse>{
  MockResponse.of('POST').respond(err, 500),
  MockResponse.of('POST').respond(err, 500),
  MockResponse.of('POST').respond(ok, 200)
}

// Usecase 側: this.http.label(LBL_EXISTS).send(req);
MockHttpRequestHandler mock = new MockHttpRequestHandler()
  .attach(LBL_EXISTS, MockResponse.of('GET').respond(notFound, 404))
  .attach(LBL_CREATE, MockResponse.of('POST').respond(created, 201))
  .attach(LBL_UPDATE, MockResponse.of('PUT').respond(updated, 200));   // 通らない分岐も宣言してよい
 
new KintoneUpsertUsecase(input, mock).invoke();
 
Assert.areEqual(1, mock.sentRequestsAt(LBL_CREATE).size());   // create 分岐を通った
Assert.areEqual(0, mock.sentRequestsAt(LBL_UPDATE).size());   // update は未消費

this.http.label(LBL_CARD_IMAGE).send(req);
String contentType = this.http.getHeader('Content-Type');
if(this.http.getStatusCode() == 200 &&(contentType == null || !contentType.startsWith('image/'))) {
  throw new CalloutException('Expected an image response but got Content-Type=' + contentType);
}
Blob image = this.http.getBodyAsBlob();

public with sharing class KintoneUpsertUsecase {
  @TestVisible static final String LBL_EXISTS = 'kintoneExists';
  @TestVisible static final String LBL_CREATE = 'kintoneCreate';
 
  private final Input input;
  private final IHttpRequestHandler http;
  private Trace t = Trace.of('kintone へレコードを upsert');
 
  // 🚪 本番用
  public KintoneUpsertUsecase(Input input) {
    this(input, null);
  }
 
  // 🧪 テスト用 (DI 対応)
  @TestVisible
  private KintoneUpsertUsecase(Input input, IHttpRequestHandler http) {
    this.input = input;
    this.http = http ?? new HttpRequestHandler();
  }
 
  public void invoke() {
    this.t.start();
    this.http.label(LBL_EXISTS).send(existsReq);
    // ...
  }
}