GraphQL Validation with Apollo Server
Let’s illustrate GraphQL validation using Apollo Server, a popular GraphQL server implementation:
const { ApolloServer, gql } = require('apollo-server');
// Define GraphQL schema
const typeDefs = gql`
type Query {
hello(name: String): String
}
`;
// Define resolvers
const resolvers = {
Query: {
hello: (_, { name }) => {
return `Hello, ${name || 'World'}!`;
},
},
};
// Create Apollo Server instance
const server = new ApolloServer({
typeDefs,
resolvers,
validationRules: [],
});
// Start the server
server.listen().then(({ url }) => {
console.log(`Server running at ${url}`);
});
In this example, we define a simple GraphQL schema with a single query field (hello) that accepts an optional name argument. Apollo Server automatically performs syntax and schema validation on incoming GraphQL queries and mutations based on the provided schema definition (typeDefs). Any validation errors encountered during query execution will be reported back to the client.
GraphQL Validation
GraphQL validation is an important step in ensuring the integrity and correctness of GraphQL queries and mutations. It involves checking the syntax, structure, and semantics of GraphQL documents to identify any errors or inconsistencies before executing them against a GraphQL server.
In this article, we will learn about GraphQL validation by its key concepts, and importance and provide practical examples to understand the process thoroughly.