graphql-document-analyzer

graphql-document-analyzer

The GraphQL document analyzer is a resilient parser that intelligently handles a variety of issues when working with GraphQL documents, including:

1. Validation issues don't throw errors and are stored as InvalidOperationDefinition and InvalidFragmentDefinition nodes
2. Top-level comments and other ignored values are stored as Ignored nodes and maintained through to the printed output
3. Previous revisions can be used to interpolate valid nodes

analyze

analyze is very similar to GraphQL's built-in parse method, with a field sections that contains all valid, invalid, and comment sections of the document. Additionally, definitions will be empty if the document has no valid definitions (instead of throwing an error).

import { analyze } from "graphql-document-analyzer";

const source = `# Notes about A
query A {
  b {
}`;

const document = analyze(source);

expect(document).toEqual({
  kind: "Document",
  definitions: [],

  // Extension of DocumentNode with sections
  sections: [
    {
      kind: "Ignored",
      value: "# Notes about A",
    },
    {
      kind: "InvalidOperationDefinition",
      value: "query A {\n  b {\n}",
    },
  ],
});

interpolate

In some situations, it is helpful to estimate what the document represents based on a previous version of the document. For example, if someone is actively editing a document, maintaining the most-recently valid operation may be helpful. Interpolation occurs at the operation level and is matched by operation name.

// (result of previous analyze / interpolate)
const reference = analyze(`query A {
  b
}`);

const document = analyze(`# Notes about A
query A {
  b {
}`);

const approximate = interpolate(document, reference);

expect(approximate).toEqual({
  kind: 'Document',
  definitions: [
    {
      kind: 'OperationDefinition',
      operation: 'query',
      name: {
        kind: 'Name',
        value: 'A'
      },
      selectionSet: {
        kind: 'SelectionSet'
        selections: [
          {
            kind: 'Field',
            name: {
              kind: 'Name',
              value: 'b'
            }
          }
        ]
      }
    }
  ],
  sections: [
    {
      kind: 'Ignored',
      value: '# Notes about A'
    },
    {
      kind: 'OperationDefinition',
      // same as above...
    }
  ]
});

visit

Visit is a section-aware visitor for extended documents, that aims to keep the document outline consistent with changes from the visitor.

import { analyze, visit } from "graphql-document-analyzer";

const source = `# Notes about A
query A {
  b {
}`;

const document = analyze(source);
const stillHasComments = visit(document, {
  OperationDefinition(node) {
    // ...
  },
});

print

To include top-level comments and invalid sections in the printed output, use print.

import { analyze, print } from "graphql-document-analyzer";

const source = `# Notes about A
query A {
  b {
}`;

const document = analyze(source);
const text = print(document);

expect(text).toEqual(source);