---
lang: ja-jp
breaks: true
---
# GraphQL `graphql-code-generator` で C#のコードを生成する 2022-08-07

[dotansimha](https://github.com/dotansimha)/**[graphql-code-generator](https://github.com/dotansimha/graphql-code-generator)**

[Home – GraphQL Code Generator (graphql-code-generator.com)](https://www.graphql-code-generator.com/#live-demo)

> C# Operations
> [Installation – GraphQL Code Generator (graphql-code-generator.com)](https://www.graphql-code-generator.com/plugins/c-sharp/c-sharp-operations)

## 使用するスキーマ

> パブリックスキーマ
> [https://docs.github.com/ja/graphql/overview/public-schema](https://docs.github.com/ja/graphql/overview/public-schema)
> https://docs.github.com/public/schema.docs.graphql

## インストール

npm install graphql
npm install -D @graphql-codegen/cli

npx graphql-code-generator init

[@graphql-codegen/c-sharp-operations - npm (npmjs.com)](https://www.npmjs.com/package/@graphql-codegen/c-sharp-operations)

npm install -D @graphql-codegen/c-sharp-operations

[@graphql-codegen/c-sharp - npm (npmjs.com)](https://www.npmjs.com/package/@graphql-codegen/c-sharp)

npm install -D @graphql-codegen/c-sharp

## ウイザードに従ってプロジェクトを設定する

npx graphql-code-generator init

## サンプルのスキーマ

### schema.graphql

scalar Date

schema {
  query: Query
}

type Query {
  me: User!
  user(id: ID!): User
  allUsers: [User]
  search(term: String!): [SearchResult!]!
  myChats: [Chat!]!
}

enum Role {
  USER
  ADMIN
}

interface Node {
  id: ID!
}

union SearchResult = User | Chat | ChatMessage

type User implements Node {
  id: ID!
  username: String!
  email: String!
  role: Role!
}

type Chat implements Node {
  id: ID!
  users: [User!]!
  messages: [ChatMessage!]!
}

type ChatMessage implements Node {
  id: ID!
  content: String!
  time: Date!
  user: User!
}

## 設定ファイル

### codegen.yml

overwrite: true
schema: schema.graphql
documents: null
generates:
  src/generated/graphql.cs:
    plugins:
      - c-sharp
  src/generated/graphql_operations.cs:
    plugins:
      - "c-sharp-operations"
  ./graphql.schema.json:
    plugins:
      - "introspection"

## 出力されたソースファイル

### graphql.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using Newtonsoft.Json;

namespace GraphQLCodeGen {
  public class Types {
    
    #region Chat
    public class Chat : Node {
      #region members
      [JsonProperty("id")]
      public string id { get; set; }
    
      [JsonProperty("messages")]
      public List<ChatMessage> messages { get; set; }
    
      [JsonProperty("users")]
      public List<User> users { get; set; }
      #endregion
    }
    #endregion
    
    #region ChatMessage
    public class ChatMessage : Node {
      #region members
      [JsonProperty("content")]
      public string content { get; set; }
    
      [JsonProperty("id")]
      public string id { get; set; }
    
      [JsonProperty("time")]
      public DateTime time { get; set; }
    
      [JsonProperty("user")]
      public User user { get; set; }
      #endregion
    }
    #endregion
    
    public interface Node {
      [JsonProperty("id")]
      string id { get; set; }
    }
    
    #region Query
    public class Query {
      #region members
      [JsonProperty("allUsers")]
      public List<User> allUsers { get; set; }
    
      [JsonProperty("me")]
      public User me { get; set; }
    
      [JsonProperty("myChats")]
      public List<Chat> myChats { get; set; }
    
      [JsonProperty("search")]
      public List<SearchResult> search { get; set; }
    
      [JsonProperty("user")]
      public User user { get; set; }
      #endregion
    }
    #endregion
    public enum Role {
      ADMIN,
      USER
    }
    
    
    #region User
    public class User : Node {
      #region members
      [JsonProperty("email")]
      public string email { get; set; }
    
      [JsonProperty("id")]
      public string id { get; set; }
    
      [JsonProperty("role")]
      public Role role { get; set; }
    
      [JsonProperty("username")]
      public string username { get; set; }
      #endregion
    }
    #endregion
  }
  
}

:::warning
`union SearchResult = User | Chat | ChatMessage`部分のソースが生成されておらず、ビルドエラーとなる。

> [\[c-sharp\] Add an implementation for GQL Union Types and Interfaces · Issue #6858 · dotansimha/graphql-code-generator (github.com)](https://github.com/dotansimha/graphql-code-generator/issues/6858)

> [Add an implementation for C# composition types by cicciodm · Pull Request #6862 · dotansimha/graphql-code-generator (github.com)](https://github.com/dotansimha/graphql-code-generator/pull/6862)

いろいろと頑張ってくれているようだがいまだにマージされず。。。

:::

### graphql_operations.cs

using System;
using Newtonsoft.Json;
using GraphQL;
using GraphQL.Client.Abstractions;

namespace GraphQLCodeGen {
}

## `@graphql-codegen/c-sharp` パッケージの設定

  /**
   * @default false
   * @description Emit C# 9.0+ records instead of classes
   *
   * @exampleMarkdown
   * ```yaml
   * generates:
   *   src/main/c-sharp/my-org/my-app/Types.cs:
   *     plugins:
   *       - c-sharp
   *     config:
   *       emitRecords: true
   * ```
   */
  emitRecords?: boolean;

  /**
   * @default Newtonsoft.Json
   * @description Library that should be used to emit JSON attributes. Ignored when `emitJsonAttributes` is `false` or not specified
   *
   * @exampleMarkdown
   * ```yaml
   * generates:
   *   src/main/c-sharp/my-org/my-app/Types.cs:
   *     plugins:
   *       - c-sharp
   *     config:
   *       jsonAttributesSource: System.Text.Json
   * ```
   */
  jsonAttributesSource?: JsonAttributesSource;

  /**
   * @description Allows you to override the type that unknown scalars will have.
   * @default any
   *
   * @exampleMarkdown
   * ```yaml {2}
   * config:
   *   defaultScalarType: unknown
   * ```
   */
  defaultScalarType?: string;

  /**
   * @description Extends or overrides the built-in scalars and custom GraphQL scalars to a custom type.
   *
   * @exampleMarkdown
   * ```yaml
   * config:
   *   scalars:
   *     DateTime: Date
   *     JSON: "{ [key: string]: any }"
   * ```
   */
  scalars?: ScalarsMap;

###### tags: `GraphQL` `graphql-code-generator` `C#` `Node.js` `@graphql-codegen/c-sharp`