@graphql-codegen/client-preset/esm/fragment-masking-plugin.js

GraphQL Code Generator preset for client.

const fragmentTypeHelper = `
export type FragmentType<TDocumentType extends DocumentTypeDecoration<any, any>> = TDocumentType extends DocumentTypeDecoration<
  infer TType,
  any
>
  ? [TType] extends [{ ' $fragmentName'?: infer TKey }]
    ? TKey extends string
      ? { ' $fragmentRefs'?: { [key in TKey]: TType } }
      : never
    : never
  : never;`;
const makeFragmentDataHelper = `
export function makeFragmentData<
  F extends DocumentTypeDecoration<any, any>,
  FT extends ResultOf<F>
>(data: FT, _fragment: F): FragmentType<F> {
  return data as FragmentType<F>;
}`;
const defaultUnmaskFunctionName = 'useFragment';
const createUnmaskFunctionTypeDefinitions = (unmaskFunctionName = defaultUnmaskFunctionName) => [
    `// return non-nullable if \`fragmentType\` is non-nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: FragmentType<DocumentTypeDecoration<TType, any>>
): TType;`,
    `// return nullable if \`fragmentType\` is undefined
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: FragmentType<DocumentTypeDecoration<TType, any>> | undefined
): TType | undefined;`,
    `// return nullable if \`fragmentType\` is nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: FragmentType<DocumentTypeDecoration<TType, any>> | null
): TType | null;`,
    `// return nullable if \`fragmentType\` is nullable or undefined
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: FragmentType<DocumentTypeDecoration<TType, any>> | null | undefined
): TType | null | undefined;`,
    `// return array of non-nullable if \`fragmentType\` is array of non-nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: Array<FragmentType<DocumentTypeDecoration<TType, any>>>
): Array<TType>;`,
    `// return array of nullable if \`fragmentType\` is array of nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: Array<FragmentType<DocumentTypeDecoration<TType, any>>> | null | undefined
): Array<TType> | null | undefined;`,
    `// return readonly array of non-nullable if \`fragmentType\` is array of non-nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: ReadonlyArray<FragmentType<DocumentTypeDecoration<TType, any>>>
): ReadonlyArray<TType>;`,
    `// return readonly array of nullable if \`fragmentType\` is array of nullable
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: ReadonlyArray<FragmentType<DocumentTypeDecoration<TType, any>>> | null | undefined
): ReadonlyArray<TType> | null | undefined;`,
];
const createUnmaskFunction = (unmaskFunctionName = defaultUnmaskFunctionName) => `
${createUnmaskFunctionTypeDefinitions(unmaskFunctionName).join('\n')}
export function ${unmaskFunctionName}<TType>(
  _documentNode: DocumentTypeDecoration<TType, any>,
  fragmentType: FragmentType<DocumentTypeDecoration<TType, any>> | Array<FragmentType<DocumentTypeDecoration<TType, any>>> | ReadonlyArray<FragmentType<DocumentTypeDecoration<TType, any>>> | null | undefined
): TType | Array<TType> | ReadonlyArray<TType> | null | undefined {
  return fragmentType as any;
}
`;
const isFragmentReadyFunction = (isStringDocumentMode) => {
    if (isStringDocumentMode) {
        return `\
export function isFragmentReady<TQuery, TFrag>(
  queryNode: TypedDocumentString<TQuery, any>,
  fragmentNode: TypedDocumentString<TFrag, any>,
  data: FragmentType<TypedDocumentString<Incremental<TFrag>, any>> | null | undefined
): data is FragmentType<typeof fragmentNode> {
  const deferredFields = queryNode.__meta__?.deferredFields as Record<string, (keyof TFrag)[]>;
  const fragName = fragmentNode.__meta__?.fragmentName as string | undefined;

  if (!deferredFields || !fragName) return true;

  const fields = deferredFields[fragName] ?? [];
  return fields.length > 0 && fields.every(field => data && field in data);
}
`;
    }
    return `\
export function isFragmentReady<TQuery, TFrag>(
  queryNode: DocumentTypeDecoration<TQuery, any>,
  fragmentNode: TypedDocumentNode<TFrag>,
  data: FragmentType<TypedDocumentNode<Incremental<TFrag>, any>> | null | undefined
): data is FragmentType<typeof fragmentNode> {
  const deferredFields = (queryNode as { __meta__?: { deferredFields: Record<string, (keyof TFrag)[]> } }).__meta__
    ?.deferredFields;

  if (!deferredFields) return true;

  const fragDef = fragmentNode.definitions[0] as FragmentDefinitionNode | undefined;
  const fragName = fragDef?.name?.value;

  const fields = (fragName && deferredFields[fragName]) || [];
  return fields.length > 0 && fields.every(field => data && field in data);
}
`;
};
/**
 * Plugin for generating fragment masking helper functions.
 */
export const plugin = (_, __, { useTypeImports, augmentedModuleName, unmaskFunctionName, emitLegacyCommonJSImports, isStringDocumentMode }, _info) => {
    const documentNodeImport = `${useTypeImports ? 'import type' : 'import'} { ResultOf, DocumentTypeDecoration${isStringDocumentMode ? '' : ', TypedDocumentNode'} } from '@graphql-typed-document-node/core';\n`;
    const deferFragmentHelperImports = `${useTypeImports ? 'import type' : 'import'} { Incremental${isStringDocumentMode ? ', TypedDocumentString' : ''} } from './graphql${emitLegacyCommonJSImports ? '' : '.js'}';\n`;
    const fragmentDefinitionNodeImport = isStringDocumentMode
        ? ''
        : `${useTypeImports ? 'import type' : 'import'} { FragmentDefinitionNode } from 'graphql';\n`;
    if (augmentedModuleName == null) {
        return [
            documentNodeImport,
            fragmentDefinitionNodeImport,
            deferFragmentHelperImports,
            `\n`,
            fragmentTypeHelper,
            `\n`,
            createUnmaskFunction(unmaskFunctionName),
            `\n`,
            makeFragmentDataHelper,
            `\n`,
            isFragmentReadyFunction(isStringDocumentMode),
        ].join(``);
    }
    return [
        documentNodeImport,
        `declare module "${augmentedModuleName}" {`,
        [
            ...fragmentTypeHelper.split(`\n`),
            `\n`,
            ...createUnmaskFunctionTypeDefinitions(unmaskFunctionName).join('\n').split('\n'),
            `\n`,
            makeFragmentDataHelper,
        ]
            .map(line => (line === `\n` || line === '' ? line : `  ${line}`))
            .join(`\n`),
        `}`,
    ].join(`\n`);
};