graphql-tag loader for Webpack lets you keep GraphQL queries in separate files.
This lib makes those work in Jest.
In your package.json,
"jest": {
"transform": {
"\\.(gql|graphql)$": "jest-transform-graphql",
".*": "babel-jest"
}
}
You have to include the .* matcher because once you define the transform property, it overrides that default.
For more on configuring Jest mappers, see Jest's Webpack tutorial.