Loading GraphQL Operation Documents from Different Sources

Loading GraphQL Operation Documents from Different Sources — GraphQL Tools documentation.

Similar to schema loading - but meant to use for GraphQL documents (query/mutation/subscription/fragment).

Any input provided as a source will be recognized by utils automatically.

It also extracts usages of gql from code files using @graphql-tools/graphql-tag-pluck.

For notes on typescript, refer to Schema Loading > Loaders

Usage

const { loadDocuments } = require('@graphql-tools/load')
const { GraphQLFileLoader } = require('@graphql-tools/graphql-file-loader')
const { CodeFileLoader } = require('@graphql-tools/code-file-loader')

// Load from string
const document1 = loadDocuments('query { f }', { loaders: [] })

// Load from a single file
const document2 = loadDocuments('./users.query.graphql', { loaders: [new GraphQLFileLoader()] })

// Load from multiple files using glob
const document3 = loadDocuments('./src/**/*.graphql', { loaders: [new GraphQLFileLoader()] })

// Load from code file
const document4 = loadDocuments('./src/my-component.ts', { loaders: [new CodeFileLoader()] })

loadDocuments returns an array of document sources. Each source object has the following structure:

interface DocumentSource {
  document: DocumentNode // Object representation of GraphQL Content
  rawSDL: string // SDL in text
  location: string // Way to access to that source
}

loadDocuments takes in additional configuration via the options object (the second argument). There are some defaults to be aware of - to learn more, see the full API documentation.

Error Handling

No Files Found

In case no documents were found and loaded via the provided glob an exception is thrown.

import { GraphQLFileLoader } from '@graphql-tools/graphql-file-loader'
import { loadDocuments } from '@graphql-tools/load'

const documents = await loadDocuments(['i-do-not-exist.graphql'], {
  loaders: [new GraphQLFileLoader()]
})

If i-do-not-exist.graphql does not exist this throws the following error:

Error:
      Unable to find any GraphQL type definitions for the following pointers:

          - *.graphql

Syntax Error within a File

In case you try to load a GraphQL file with invalid syntax, the loadDocuments function will throw a GraphQLError.

You can identify the exact file that caused this GraphQLError by using the errors source property.

import { GraphQLError } from 'graphql'
import { CodeFileLoader } from '@graphql-tools/code-file-loader'
import { GraphQLFileLoader } from '@graphql-tools/graphql-file-loader'
import { loadDocuments } from '@graphql-tools/load'

try {
  const documents = await loadDocuments(['packages/**/*.graphql', 'packages/**/*.ts(x)'], {
    loaders: [new GraphQLFileLoader(), new CodeFileLoader()]
  })
  console.log(documents)
} catch (error) {
  if (error instanceof GraphQLError) {
    console.log(error.message + `\n in ${error.source?.name}`)
  }
  throw error
}