babel-plugin-graphql-tag

babel-plugin-graphql-tag

Compiles GraphQL tagged template strings using graphql-tag.

Motivation

Compiling GraphQL queries at the build time:

• reduces the script initialization time; and
• removes the graphql-tag dependency

Removing the graphql-tag dependency from the bundle saves approx. 50 KB.

Implementation

• Searches for imports of graphql-tag and removes them.
• Searches for tagged template literals with gql identifier and compiles them using graphql-tag.

Example compilation

Input:

import gql from 'graphql-tag';
// if using apollo v3
import { gql } from '@apollo/client';

const foo = gql`query {bar}`;

Output:

const foo = {
  "definitions": [
    {
      "directives": [
      ],
      "kind": "OperationDefinition",
      "operation": "query",
      "selectionSet": {
        "kind": "SelectionSet",
        "selections": [
          {
            "alias": null,
            "arguments": [
            ],
            "directives": [
            ],
            "kind": "Field",
            "name": {
              "kind": "Name",
              "value": "bar"
            },
            "selectionSet": null
          }
        ]
      },
      "variableDefinitions": [
      ]
    }
  ],
  "kind": "Document",
  "loc": {
    "end": 11,
    "start": 0
  }
};

NOTE: require() is also supported.

Using fragments

Using GraphQL fragments requires to:

1. Define a fragment using graphql-tag.
2. Append the referenced fragment as a variable to the end of the GraphQL query.

Example:

import gql from 'graphql-tag';

const bar = gql`
  fragment barFragment on Foo {
    field1
    field2
  }
`;

const foo = gql`
  query foo {
    foo {
      ...barFragment
    }
  }

  ${bar}
`;

Options

• importSources - An array of names for modules to import (default = ["graphql-tag", "@apollo/client"])
• onlyMatchImportSuffix - Matches the end of the import instead of the entire name. Useful for relative imports, e.g. ./utils/graphql (default = false)
• strip - Strips insignificant characters such as whitespace from the original GraphQL string literal to reduce the size of compiled AST (default = false)
• transform - By default, graphql query strings will be replaced with their AST representations, but you can override that behavior and do whatever you like. One possible use case would be to implement persisted queries:
• gqlTagIdentifiers - An array of names for gql tag identifiers (default = ["gql"])

// babel.config.js
plugins: [
    [
        "babel-plugin-graphql-tag",
        {
            strip: true,
            transform: (source, ast) => {
                const h = hash(source); // use your favorite hashing method
                graphqlAstHashes[h] = ast; // write this to a file when compilation is complete
                return {
                    queryId: h
                };
            }
        }
    ]
]

Known Issues

Some cases are really hard to track down:

const apolloClient = require('@apollo/client');
// or
import apolloClient from '@apollo/client';

const { gql } = apolloClient;

const foo = gql`...`;

If you have this kind of syntax, this plugin won't work for you.