@graphql-eslint/eslint-plugin/esm/rules/require-nullable-result-in-root/index.js

GraphQL plugin for ESLint

import { Kind } from "graphql";
import { getNodeName, requireGraphQLSchema } from "../../utils.js";
const RULE_ID = "require-nullable-result-in-root";
const rule = {
  meta: {
    type: "suggestion",
    hasSuggestions: true,
    docs: {
      category: "Schema",
      description: "Require nullable fields in root types.",
      url: `https://the-guild.dev/graphql/eslint/rules/${RULE_ID}`,
      requiresSchema: true,
      examples: [
        {
          title: "Incorrect",
          code: (
            /* GraphQL */
            `
            type Query {
              user: User!
            }
          `
          )
        },
        {
          title: "Correct",
          code: (
            /* GraphQL */
            `
            type Query {
              foo: User
              baz: [User]!
              bar: [User!]!
            }
          `
          )
        }
      ]
    },
    messages: {
      [RULE_ID]: "Unexpected non-null result {{ resultType }} in {{ rootType }}"
    },
    schema: []
  },
  create(context) {
    const schema = requireGraphQLSchema(RULE_ID, context);
    const rootTypeNames = new Set(
      [schema.getQueryType(), schema.getMutationType()].filter((v) => !!v).map((type) => type.name)
    );
    const sourceCode = context.getSourceCode();
    return {
      "ObjectTypeDefinition,ObjectTypeExtension"(node) {
        if (!rootTypeNames.has(node.name.value)) return;
        for (const field of node.fields || []) {
          if (field.gqlType.type !== Kind.NON_NULL_TYPE || field.gqlType.gqlType.type !== Kind.NAMED_TYPE)
            continue;
          const name = field.gqlType.gqlType.name.value;
          const type = schema.getType(name);
          const resultType = type?.astNode ? getNodeName(type.astNode) : type?.name;
          context.report({
            node: field.gqlType,
            messageId: RULE_ID,
            data: {
              resultType: resultType || "",
              rootType: getNodeName(node)
            },
            suggest: [
              {
                desc: `Make ${resultType} nullable`,
                fix(fixer) {
                  const text = sourceCode.getText(field.gqlType);
                  return fixer.replaceText(field.gqlType, text.replace("!", ""));
                }
              }
            ]
          });
        }
      }
    };
  }
};
export {
  rule
};