Schema Stitching通过添加前缀来解决冲突

Question

所以我有这两个模式

Schema1

type Permission {
    relation: Relation
}

enum Relation {
    ONE
    TWO
    THREE
}

SCHEMA2

type Permission {
    relation: Relation
}

enum Relation {
    FOUR
    FIVE
    SIX
}  

预期结果类似于:(但我对不同的想法持开放态度)合并后我想做的查询是:

{
    permissions{
        relation
    }
}

得到一个结果

"permissions": [
  {
    "relation": "ONE"
  },
  {
    "relation": "SIX"
  }
]

要么

"permissions": [
  {
    "relation": "schema1ONE"
  },
  {
    "relation": "schema2SIX"
  }
]

和突变像:

mutation{
  createPermission(
    relation: ONE
  ){
    relation
  }
}

mutation{
  createPermission(
    relation: SIX
  ){
    relation
  }
}

要么

mutation{
  createPermission(
    relation: schema1ONE
  ){
    relation
  }
}

mutation{
  createPermission(
    relation: schema2SIX
  ){
    relation
  }
}

我正在尝试transformSchema在graphql-tools上使用该函数,但无法正确理解它:

const Schema1 = await getRemoteSchema('schema1_url', 'schema1');
const Schema2 = await getRemoteSchema('schema2_url', 'schema2');

const schemas = [Schema1, Schema2]

const schema = mergeSchemas({
  schemas: schemas,
  resolvers: {}
});

getRemoteSchema定义

export const getRemoteSchema = async (uri: string, schemaName: string): Promise<GraphQLSchema> => {
  const httpLink = new HttpLink({ uri, fetch });

  const schema = await introspectSchema(httpLink);

  const executableSchema = makeRemoteExecutableSchema({
    schema,
    httpLink,
  });

  // transform schema by renaming root fields and types
  const renamedSchema = transformSchema(
    executableSchema,
    [
      new RenameTypes(name => {
        if (name == 'Relation') {
          return schemaName + name
        } else {
          return name
        }
      }),
      // new RenameRootFields((operation, name) => `${schemaName}_${name}`)
    ]
  );

  return renamedSchema;
}    

我做了这个小故障https://glitch.com/edit/#!/schema-stitching-conflict 因此更容易看到问题.

Answer 1

您需要RenameTypes和RenameRootFields转换 RenameTypes来转换类型名称

来自：Permission和Relation（碰撞类型），

到：schema1_Permission，schema2_Permission

和：schema1_Relation，schema1_Relation

RenameRootFields转换这些类型的查询名称

从：permission(id: ID!): Permission

至：schema1_permission(id: ID!): schema1_Permission和schema2_permission(id: ID!): schema2_Permission

和：permissions: [Permission]

至：schema1_permissions: [schema1_Permission]和schema2_permissions: [schema2_Permission]

转换将类似于：

const {
  makeExecutableSchema,
  addMockFunctionsToSchema,
  transformSchema,
  RenameTypes,
  RenameRootFields
} = require('graphql-tools');

const schema1 = makeExecutableSchema({
  typeDefs: `
    type Permission {
      id: ID!
      text: String
      relation: Relation
    }

    type Query {
      permissions: [Permission]
      permission(id: ID!): Permission
    }

    enum Relation {
      ONE
      TWO
      THREE
    }
  `
});

addMockFunctionsToSchema({ schema: schema1 });

const renamedSchema1 = transformSchema(
  schema1,
  [
    new RenameTypes(name => {
      if (name == 'Relation' || name == 'Permission') {
        return 'schema1_' + name
      } else {
        return name
      }
    }, { renameBuiltins: false, renameScalars: true }),
    new RenameRootFields((_op, name) => {
      return name.includes('ermission') ? `schema1_${name}` : name
    })
  ]
);

参考资料： https://www.apollographql.com/docs/graphql-tools/schema-transforms/ https://www.apollographql.com/docs/graphql-tools/schema-stitching/