graphql-anywhere/src/__tests__/index.ts

Run GraphQL queries with no schema and just one resolver

import gql from 'graphql-tag';

import { Resolver, ExecInfo } from '..';

const execute = (graphql, r) => () => {
  it('does basic things', async () => {
    const resolver = (_, root) => r(root + 'fake');

    const query = gql`
      {
        a {
          b
          ...frag
        }
      }

      fragment frag on X {
        c
      }
    `;

    const result = await graphql(resolver, query, '', null, null);

    expect(result).toEqual({
      a: {
        b: 'fakefake',

        c: 'fakefake',
      },
    });
  });

  it('works with enum args', async () => {
    const resolver = (fieldName, root, args) => r(args.value);

    const query = gql`
      {
        a(value: ENUM_VALUE)
      }
    `;

    const result = await graphql(resolver, query);

    expect(result).toEqual({ a: 'ENUM_VALUE' });
  });

  it('works with null args', async () => {
    const resolver = (fieldName, root, args) => r(args.value);

    const query = gql`
      {
        a(value: null)
      }
    `;

    const result = await graphql(resolver, query);

    expect(result).toEqual({ a: null });
  });

  it('traverses arrays returned from the resolver', async () => {
    const resolver = () => r([1, 2]);

    const query = gql`
      {
        a {
          b
        }
      }
    `;

    const result = await graphql(resolver, query);

    expect(result).toEqual({ a: [{ b: [1, 2] }, { b: [1, 2] }] });
  });

  it('can traverse an object', async () => {
    const obj = {
      a: {
        b: 'fun',

        c: ['also fun', 'also fun 2'],

        d: 'not fun',
      },
    };

    const resolver = (fieldName, root) => r(root[fieldName]);

    const query = gql`
      {
        a {
          b
          c
        }
      }
    `;

    const result = await graphql(resolver, query, obj, null, null);

    expect(result).toEqual({
      a: {
        b: 'fun',

        c: ['also fun', 'also fun 2'],
      },
    });
  });

  it('can traverse nested arrays', async () => {
    const obj = { a: [{ b: [[{ c: 1 }, { c: 2 }], [{ c: 3 }, { c: 4 }]] }] };

    const resolver = (fieldName, root) => r(root[fieldName]);

    const query = gql`
      {
        a {
          b {
            c
          }
        }
      }
    `;

    const result = await graphql(resolver, query, obj, null, null);

    expect(result).toEqual({
      a: [{ b: [[{ c: 1 }, { c: 2 }], [{ c: 3 }, { c: 4 }]] }],
    });
  });

  it('can use arguments, both inline and variables', async () => {
    const resolver = (fieldName, _, args) => r(args);

    const query = gql`
      {
        inline(int: 5, float: 3.14, string: "string")
        variables(int: $int, float: $float, string: $string)
      }
    `;

    const variables = {
      int: 6,

      float: 6.28,

      string: 'varString',
    };

    const result = await graphql(resolver, query, null, null, variables);

    expect(result).toEqual({
      inline: {
        int: 5,

        float: 3.14,

        string: 'string',
      },

      variables: {
        int: 6,

        float: 6.28,

        string: 'varString',
      },
    });
  });

  it('will tolerate missing variables', async () => {
    const resolver = (fieldName, _, args) => r(args);

    const query = gql`
      {
        variables(int: $int, float: $float, string: $string, missing: $missing)
      }
    `;

    const variables = {
      int: 6,

      float: 6.28,

      string: 'varString',
    };

    const result = await graphql(resolver, query, null, null, variables);

    expect(result).toEqual({
      variables: {
        int: 6,

        float: 6.28,

        string: 'varString',

        missing: undefined,
      },
    });
  });

  it('can use skip and include', async () => {
    const resolver = fieldName => r(fieldName);

    const query = gql`
      {
        a {
          b @skip(if: true)
          c @include(if: true)
          d @skip(if: false)
          e @include(if: false)
        }
      }
    `;

    const result = await graphql(resolver, query, null, null);

    expect(result).toEqual({
      a: {
        c: 'c',

        d: 'd',
      },
    });
  });

  it('can use inline and named fragments', async () => {
    const resolver = fieldName => r(fieldName);

    const query = gql`
      {
        a {
          ... on Type {
            b
            c
          }
          ...deFrag
        }
      }

      fragment deFrag on Type {
        d
        e
      }
    `;

    const result = await graphql(resolver, query, null, null, null);

    expect(result).toEqual({
      a: {
        b: 'b',

        c: 'c',

        d: 'd',

        e: 'e',
      },
    });
  });

  it('can resolve deeply nested fragments', async () => {
    const resolver = (fieldName, root) => {
      return r(root[fieldName]);
    };

    const query = gql`
      {
        stringField
        numberField
        nullField
        ... on Item {
          nestedObj {
            stringField
            nullField
            deepNestedObj {
              stringField
              nullField
            }
          }
        }
        ... on Item {
          nestedObj {
            numberField
            nullField
            deepNestedObj {
              numberField
              nullField
            }
          }
        }
        ... on Item {
          nullObject
        }
        nestedObj {
          inlinedObjectStringField
        }
      }
    `;

    const result: any = {
      id: 'abcd',

      stringField: 'This is a string!',

      numberField: 5,

      nullField: null,

      nestedObj: {
        id: 'abcde',

        stringField: 'This is a string too!',

        numberField: 6,

        nullField: null,

        deepNestedObj: {
          stringField: 'This is a deep string',

          numberField: 7,

          nullField: null,
        },

        inlinedObjectStringField: 'This is a string of an inlined object',
      },

      nullObject: null,
    };

    const queryResult = await graphql(resolver, query, result);

    // The result of the query shouldn't contain __data_id fields

    expect(queryResult).toEqual({
      stringField: 'This is a string!',

      numberField: 5,

      nullField: null,

      nestedObj: {
        stringField: 'This is a string too!',

        numberField: 6,

        nullField: null,

        deepNestedObj: {
          stringField: 'This is a deep string',

          numberField: 7,

          nullField: null,
        },

        inlinedObjectStringField: 'This is a string of an inlined object',
      },

      nullObject: null,
    });
  });

  it('can resolve deeply nested fragments with arrays', async () => {
    const resolver = (fieldName, root) => {
      return r(root[fieldName]);
    };

    const query = gql`
      {
        ... on Item {
          array {
            id
            field1
          }
        }
        ... on Item {
          array {
            id
            field2
          }
        }
        ... on Item {
          array {
            id
            field3
          }
        }
      }
    `;

    const result: any = {
      array: [
        {
          id: 'abcde',

          field1: 1,

          field2: 2,

          field3: 3,
        },
      ],
    };

    const queryResult = await graphql(resolver, query, result);

    expect(queryResult).toEqual({
      array: [
        {
          id: 'abcde',

          field1: 1,

          field2: 2,

          field3: 3,
        },
      ],
    });
  });

  it('passes info including isLeaf, resultKey, directives, and field', async () => {
    const leafMap: { [s: string]: ExecInfo } = {};

    const resolver: Resolver = (fieldName, root, args, context, info) => {
      leafMap[fieldName] = info;

      return r('continue');
    };

    const query = gql`
      {
        alias: a {
          b
          hasDirective @skip(if: false) @otherDirective(arg: $x)
        }
      }
    `;

    await graphql(resolver, query, null, null, { x: 'argument' });

    expect(leafMap).toEqual({
      a: {
        directives: null,

        isLeaf: false,

        resultKey: 'alias',

        field: expect.any(Object),
      },

      b: {
        directives: null,

        isLeaf: true,

        resultKey: 'b',

        field: expect.any(Object),
      },

      hasDirective: {
        directives: {
          skip: { if: false },

          otherDirective: { arg: 'argument' },
        },

        isLeaf: true,

        resultKey: 'hasDirective',

        field: expect.any(Object),
      },
    });
  });

  it('can filter GraphQL results', async () => {
    const data = {
      alias: 'Bob',

      name: 'Wrong',

      height: 1.89,

      avatar: {
        square: 'abc',

        circle: 'def',

        triangle: 'qwe',
      },
    };

    const fragment = gql`
      fragment PersonDetails on Person {
        alias: name
        height(unit: METERS)
        avatar {
          square
          ... on Avatar {
            circle
          }
        }
      }
    `;

    const resolver: Resolver = (fieldName, root, args, context, info) => {
      return r(root[info.resultKey]);
    };

    const filtered = await graphql(resolver, fragment, data);

    expect(filtered).toEqual({
      alias: 'Bob',

      height: 1.89,

      avatar: {
        square: 'abc',

        circle: 'def',
      },
    });
  });

  it('can handle mutations', async () => {
    const resolver = (fieldName, root, args) => {
      let value;

      if (fieldName === 'operateOnNumbers') {
        value = args;
      } else if (fieldName === 'add') {
        value = root.a + root.b;
      } else if (fieldName === 'subtract') {
        value = root.a - root.b;
      } else if (fieldName === 'multiply') {
        value = root.a * root.b;
      } else if (fieldName === 'divide') {
        value = root.a / root.b;
      }

      return r(value);
    };

    const query = gql`
      mutation {
        operateOnNumbers(a: 10, b: 2) {
          add
          subtract
          multiply
          divide
        }
      }
    `;

    const result = await graphql(resolver, query, '', null, null);

    expect(result).toEqual({
      operateOnNumbers: {
        add: 12,

        subtract: 8,

        multiply: 20,

        divide: 5,
      },
    });
  });

  it('does not error on subscriptions', async () => {
    const data = {
      user: {
        id: 1,

        name: 'Some User',

        height: 1.89,
      },
    };

    const resolver = (fieldName, root) => r(root[fieldName]);

    const query = gql`
      subscription {
        user {
          id
          name
          height
        }
      }
    `;

    const result = await graphql(resolver, query, data);

    expect(result).toEqual({
      user: {
        id: 1,

        name: 'Some User',

        height: 1.89,
      },
    });
  });

  it('can handle documents with multiple fragments', async () => {
    const data = {
      user: {
        id: 1,

        name: 'Some User',

        height: 1.89,
      },
    };

    const resolver = (fieldName, root) => r(root[fieldName]);

    const query = gql`
      fragment A on User {
        name
      }

      fragment B on User {
        height
      }

      query {
        user {
          id
          ...A
          ...B
        }
      }
    `;

    const result = await graphql(resolver, query, data);

    expect(result).toEqual({
      user: {
        id: 1,

        name: 'Some User',

        height: 1.89,
      },
    });
  });

  describe('examples', () => {
    it('readme example', async () => {
      // I don't need all this stuff!

      const gitHubAPIResponse = {
        url: 'https://api.github.com/repos/octocat/Hello-World/issues/1347',

        title: 'Found a bug',

        body: "I'm having a problem with this.",

        user: {
          login: 'octocat',

          avatar_url: 'https://github.com/images/error/octocat_happy.gif',

          url: 'https://api.github.com/users/octocat',
        },

        labels: [
          {
            url: 'https://api.github.com/repos/octocat/Hello-World/labels/bug',

            name: 'bug',

            color: 'f29513',
          },
        ],
      };

      // Write a query that gets just the fields we want

      const query = gql`
        {
          title
          user {
            login
          }
          labels {
            name
          }
        }
      `;

      // Define a resolver that just returns a property

      const resolver = (fieldName, root) => root[fieldName];

      // Filter the data!

      const result = await graphql(resolver, query, gitHubAPIResponse);

      expect(result).toEqual({
        title: 'Found a bug',

        user: { login: 'octocat' },

        labels: [{ name: 'bug' }],
      });
    });

    it('readme example 2', async () => {
      // Write a query where the fields are types, but we alias them

      const query = gql`
        {
          author {
            name: string
            age: int
            address {
              state: string
            }
          }
        }
      `;

      // Define a resolver that uses the field name to determine the type

      // Note that we get the actual name, not the alias, but the alias

      // is used to determine the location in the response

      const resolver = fieldName =>
        ({ string: 'This is a string', int: 5 }[fieldName] || 'continue');

      // Generate the object!

      const result = await graphql(resolver, query);

      expect(result).toEqual({
        author: {
          name: 'This is a string',

          age: 5,

          address: { state: 'This is a string' },
        },
      });
    });

    it('read from Redux normalized store', async () => {
      const data = {
        result: [1, 2],

        entities: {
          articles: {
            1: { id: 1, title: 'Some Article', author: 1 },

            2: { id: 2, title: 'Other Article', author: 1 },
          },

          users: { 1: { id: 1, name: 'Dan' } },
        },
      };

      const query = gql`
        {
          result {
            title
            author {
              name
            }
          }
        }
      `;

      const schema = { articles: { author: 'users' } };

      // This resolver is a bit more complex than others, since it has to

      // correctly handle the root object, values by ID, and scalar leafs.

      const resolver = (fieldName, rootValue, args, context): any => {
        if (!rootValue) {
          return context.result.map(id => {
            return {
              ...context.entities.articles[id],

              __typename: 'articles',
            };
          });
        }

        const typename = rootValue.__typename;

        // If this field is a reference according to the schema

        if (typename && schema[typename] && schema[typename][fieldName]) {
          // Get the target type, and get it from entities by ID

          const targetType: string = schema[typename][fieldName];

          return {
            ...context.entities[targetType][rootValue[fieldName]],

            __typename: targetType,
          };
        }

        // This field is just a scalar

        return rootValue[fieldName];
      };

      const result = await graphql(
        resolver,
        query,
        null,
        data, // pass data as context since we have to access it all the time
      );

      // This is the non-normalized data, with only the fields we asked for in our query!

      expect(result).toEqual({
        result: [
          {
            title: 'Some Article',

            author: { name: 'Dan' },
          },

          {
            title: 'Other Article',

            author: { name: 'Dan' },
          },
        ],
      });
    });
  });
};

describe('basic operations done sync', execute(require('../').default, x => x));

describe(
  'basic operations done async',
  execute(require('../async').graphql, x => Promise.resolve(x)),
);