如何在typescript/javascript导出中使用字符串模板处理graphql-codegen模式

Question

我使用graphql-codegen生成给定模式的类型文件。

除了在导出的方案中有字符串模板之外，所有这些都是好的，它会抱怨sytax并似乎不会编译它。有关详细信息，请查看下列文件。

types.js如下：

const gql = require("graphql-tag");

const Colors = ["Red", "Yellow"];
export default gql`
  type Person {
    name: String
  }
  enum Color {
      ${Colors.join("\n")}
  }
# if we change the above enum to be the below, it will be good
#   enum Color {
#       Red
#       Yellow
#   }
`;

而config yml文件是：

schema: 
  - types.js

generates:
  generated.ts:
    plugins:
        - typescript
        - typescript-resolvers

当运行yarn graphql:codegen时，它会抱怨如下：

Found 1 error

  ✖ generated.ts
    Failed to load schema from types.js:

        Syntax Error: Expected Name, found }
        GraphQLError: Syntax Error: Expected Name, found }
    at syntaxError (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/error/syntaxError.js:15:10)
    at Parser.expectToken (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:1404:40)
    at Parser.parseName (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:94:22)
    at Parser.parseEnumValueDefinition (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:1014:21)
    at Parser.optionalMany (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:1497:28)
    at Parser.parseEnumValuesDefinition (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:1002:17)
    at Parser.parseEnumTypeDefinition (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:986:23)
    at Parser.parseTypeSystemDefinition (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:705:23)
    at Parser.parseDefinition (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:146:23)
    at Parser.many (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:1518:26)
    at Parser.parseDocument (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:111:25)
    at Object.parse (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/graphql/language/parser.js:36:17)
    at Object.parseGraphQLSDL (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/@graphql-toolkit/common/index.cjs.js:572:28)
    at CodeFileLoader.load (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/@graphql-toolkit/code-file-loader/index.cjs.js:120:31)
    at async /Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/@graphql-toolkit/core/index.cjs.js:682:25
    at async Promise.all (index 0)

        GraphQL Code Generator supports:
          - ES Modules and CommonJS exports (export as default or named export "schema")
          - Introspection JSON File
          - URL of GraphQL endpoint
          - Multiple files with type definitions (glob expression)
          - String in config file

        Try to use one of above options and run codegen again.
    Error: Failed to load schema
        at loadSchema (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/@graphql-codegen/cli/bin.js:353:15)
    Error: Failed to load schema
        at loadSchema (/Users/rliu/study/reproduce-graphql-codegen-with-string-template-in-js-export/node_modules/@graphql-codegen/cli/bin.js:353:15)

看起来graphql-codegen不喜欢模板字符串，比如：${Colors.join('\n')}。

另外，请查看包含上述所有文件的存储库。

谁能帮上忙？谢谢。

Answer 1

它没有处理它，主要是因为加载代码文件和插值代码文件的复杂性。但是，解决办法是：

• 创建一个schema.js文件。
• 从源文件导入带有字符串内插的所有类型，并使用buildSchema (来自graphql)或makeExecutableSchema (来自graphql-tools)构建GraphQLSchema对象实例。
• 将GraphQLSchema导出为默认导出，或作为名为schema的标识符导出。
• 将该文件提供给codegen (通过执行schema: ./schema.js --使用单个代码文件会使编码元查找ast代码，然后尝试对其执行require )。

如果您使用的是TypeScript，您还应该在编码元中添加require扩展(参见https://graphql-code-generator.com/docs/getting-started/require-field#typescript-support)。