Define resolver for Custom scalar type about graphql

[dcasier]

Another temporary solution :

  import { ResolversExplorerService } from '@nestjs/graphql/resolvers-explorer.service'
  import { makeExecutableSchema } from 'graphql-tools'

  const resolverFunctions = {
    CustomScalar: myCustomScalarType
  }

  (...)

  createSchema() {
    const typeDefs = this.graphQLFactory.mergeTypesByPaths('./**/*.gql')
    //const schema = this.graphQLFactory.createSchema(typeDefs)

    const resolvers = this.resolversExplorerService.explore()
    Object.assign(resolvers, customScalarsFunctions)

    const schema = makeExecutableSchema({
      typeDefs,
      resolvers: resolvers,
    })
    return schema
  }

[pawpartyka]

@valburyakov I also had a problem with it.

Solution:

date-time.scalar-type.ts

// ...
export const GraphQLDateTime = new GraphQLScalarType({
  name: 'DateTime',
  parseValue(value) {
    return new Date(value);
  },
  serialize(value) {
    return moment(value).toISOString();
  },
  parseLiteral(ast) {
    if (ast.kind === Kind.STRING) {
      return new Date(ast.value);
    }

    return null;
  },
});

bootstrap.ts

/** Scalar types **/
import { scalarTypes } from './type-implementations';

// ....

export class AppModule {

  // .........

  private createSchema(): GraphQLSchema {
    const schema = this.graphQLFactory.createSchema({
      typeDefs: [
        this.graphQLFactory.mergeTypesByPaths('./**/*.graphqls'),
      ],
      resolvers: {
        ...scalarTypes,
      },
      directiveResolvers: {},
    });

    const delegates = this.graphQLFactory.createDelegates();

    return mergeSchemas({
      schemas: [
        schema,
      ],
      resolvers: delegates,
    });
  }
}

But resolvers in createSchema function have problem, because this function overwrite resolvers property. I created pull request to fix it. Maybe there are other better solutions, but I have not found one.

[valburyakov]

@partyka95 Thx for the solution. But for me it still doesn't work, I did like in your example but no resolver for custom scalar is loaded:

app.module.ts

createSchema() {
    const typeDefs = this.graphQLFactory.mergeTypesByPaths('./**/*.graphql');
    const schema = this.graphQLFactory.createSchema({
      typeDefs,
      resolvers: {
        Date: GraphQLDateTime
      },
      directiveResolvers: {},
    });

    const delegates = this.graphQLFactory.createDelegates();

    return mergeSchemas({
      schemas: [
        schema,
      ],
      resolvers: delegates
    });
  }

Or this solution is working only with your fix in PR ? And show your scalarTypes .

[pawpartyka]

@valburyakov :

https://github.com/excitement-engineer/graphql-iso-date

#8

[kamilmysliwiec]

Fixed thanks to #8 pull request. I'll push it together with the incoming release 🙂

[lock]

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