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https://github.com/sunesimonsen/graphql-fakester
Create stub data from a GraphQL schema
https://github.com/sunesimonsen/graphql-fakester
Last synced: 19 days ago
JSON representation
Create stub data from a GraphQL schema
- Host: GitHub
- URL: https://github.com/sunesimonsen/graphql-fakester
- Owner: sunesimonsen
- Created: 2022-03-01T19:28:27.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-17T06:57:07.000Z (5 months ago)
- Last Synced: 2024-10-19T03:24:47.567Z (about 1 month ago)
- Language: JavaScript
- Size: 377 KB
- Stars: 4
- Watchers: 3
- Forks: 0
- Open Issues: 8
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
Awesome Lists containing this project
README
# graphql-fakester
Create stub data by querying a GraphQL schema.
This might be useful together with something like the [Apollo](https://www.apollographql.com/) [MockProvider](https://www.apollographql.com/docs/react/development-testing/testing/).
## Installation
```sh
npm install graphql-fakester
```
## Usage
```js
import { GraphQLMock } from "graphql-fakester";
const typeDefs = `
type Author {
id: ID!
firstName: String
lastName: String
email: String
posts: [Post]
}
type Comment {
id: ID!
text: String!
}
type CommentConnectionEdge {
cursor: String!
node: Comment
}
type PageInfo {
hasNextPage: Boolean!
hasPreviousPage: Boolean!
startCursor: String
endCursor: String
}
type CommentConnection {
edges: [CommentConnectionEdge!]!
total: Int!
pageInfo: PageInfo!
}
type Post {
id: ID!
title: String
text: String
author: Author
votes: Int
comments(
first: Int
last: Int
after: String
before: String
): CommentConnection!
}
type Query {
posts: [Post]
author(id: ID!): Author
}
type Mutation {
upvotePost(postId: ID!): Post
}
`;
let mock = new GraphQLMock({ typeDefs });
const authorQuery = `
query authorFirstName($id: ID!) {
author(id: $id) {
firstName
lastName
email
posts {
id
title
}
}
}
`;
let result = await mock.execute(authorQuery, { id: "42" });
expect(result, "to satisfy", {
data: {
author: {
id: "4945079106011136",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "jeminode" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
You can also provide the query and the variables as an option object:
```js
result = await mock.execute({ query: authorQuery, variables: { id: "42" } });
expect(result, "to satisfy", {
data: {
author: {
id: "4945079106011136",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "jeminode" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
## Overriding the default mocks
This project uses [@graphql-tools/mock](https://www.graphql-tools.com/docs/mocking) as its basis and can be used in a very similar way.
If you just want to hardcode an override, you can do that the following way:
```js
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: {
id: "author-0",
firstName: "Jane",
lastName: "Doe",
posts: [{ title: "First post" }, {}],
},
},
});
result = await mock.execute(authorQuery, { id: "42" });
expect(result, "to satisfy", {
data: {
author: {
id: "4945079106011136",
firstName: "Jane",
lastName: "Doe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "First post" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
In case you need to seeded generate random data from a override, you can provide a function.
The each of the top-level override function will be given a [chancejs](https://www.chancejs.com) instance that can be used to generate random seeded data, a root object containing the resolved parent data, an args object containing the arguments for the query, a context and an info object containing information about the query.
See the [mocking documentation](https://www.graphql-tools.com/docs/mocking) for more details.
## Mocking a list resolver
```js
import { list } from "graphql-fakester";
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: {
id: "author-0",
firstName: "Jane",
lastName: "Doe",
posts: list(3),
},
},
});
result = await mock.execute(authorQuery, { id: "42" });
expect(result, "to satisfy", {
data: {
author: {
id: "4945079106011136",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "jeminode" },
{ id: "4158848130613248", title: "orimipon" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
You can use [chance](https://chancejs.com/) to create a variable length list this way.
```js
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: chance => ({
id: "author-0",
posts: list(chance.integer{ min: 1, max: 5 }),
}),
},
});
result = await mock.execute(authorQuery, { id: "42" });
expect(result, "to satisfy", {
data: {
author: {
id: j4945079106011136j,
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "jeminode" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
Notice `min` defaults to 0 and `max` defaults to 10, so can just call the list function without any arguments, or only send in either `min` or `max`.
## Mock a Relay connection resolver
```js
import { connection } from "graphql-fakester";
mock = new GraphQLMock({
typeDefs,
mocks: {
posts: list(1),
CommentConnection: connection(1, { includeTotal: true }),
},
});
const postsQuery = `
query postsQuery {
posts {
id
title
comments(first: 1) {
edges {
cursor
node {
id
text
}
}
pageInfo {
hasNextPage
hasPreviousPage
hasNextPage
endCursor
}
total
}
}
}
`;
result = await mock.execute(postsQuery);
expect(result, "to satisfy", {
data: {
posts: [
{
id: "4945079106011136",
title: "herubju",
comments: {
edges: [
{
cursor: "cursor-0",
node: { id: "6325555974635520", text: "nocpebe" },
},
],
pageInfo: {
hasNextPage: true,
hasPreviousPage: false,
endCursor: "cursor-0",
},
total: 1,
},
},
],
},
});
```
Options:
- includeTotal (false): If a total field should be included
- hasNextPage (true): sets the pageInfo.hasNextPage value
- hasPreviousPage (false): sets the pageInfo.hasPreviousPage value
## Overriding a special list entry
You can get a sequence number corresponding to the number of time a mock has been resolved. This can be used to respond specially for a certain index in a list:
```js
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: {
id: "author-0",
posts: list(5),
},
Post: (chance, seq) =>
seq === 3 ? { id: "post-0", title: "My very special title" } : {},
},
});
result = await mock.execute(authorQuery, { id: authorId });
expect(result, "to satisfy", {
data: {
author: {
id: "4945079106011136",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "6325555974635520", title: "jeminode" },
{ id: "308014672248832", title: "orimipon" },
{ id: "1702188611010560", title: "rurzilru" },
{ id: "1828976169320448", title: "My very special title" },
{ id: "4158848130613248", title: "lufzipav" },
],
},
},
});
```
## Cycling through mocks
Sometimes it is useful to provide a cycle through a finite list of mocks. You can use the `cycle` utility for this purpose.
```js
import { cycle } from "graphql-fakester";
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: {
id: "author-0",
posts: list(5),
},
Post: cycle(
{ id: "post-0", title: "foo" },
(chance) => ({
id: String(chance.natural()),
title: `bar-${chance.word()}`,
}),
{ id: "post-2", title: "baz" }
),
},
});
result = await mock.execute(authorQuery, { id: authorId });
expect(result, "to satisfy", {
data: {
author: {
id: "author-0",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "post-0", title: "foo" },
{ id: "308014672248832", title: "bar-ketis" },
{ id: "post-1", title: "baz" },
{ id: "post-0", title: "foo" },
{ id: "4158848130613248", title: "bar-ziluwi" },
],
},
},
});
```
## Using a specific list of mocks
In other cases you might want to specify the first `n` mocks and just repeat the last one, you can do that with the `values` utility.
Notice that the last mock will be repeated when all the initial mocks has been used, so it is a good idea to put some randomness into the final mock.
```js
import { values } from "graphql-fakester";
mock = new GraphQLMock({
typeDefs,
mocks: {
Author: {
id: "author-0",
posts: list(5),
},
Post: values(
{ id: "post-0", title: "foo" },
{ id: "post-1", title: "bar" },
(chance) => ({
id: String(chance.natural()),
title: `baz-${chance.word()}`,
})
),
},
});
result = await mock.execute(authorQuery, { id: authorId });
expect(result, "to satisfy", {
data: {
author: {
id: "author-0",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "post-0", title: "foo" },
{ id: "post-1", title: "bar" },
{ id: "1702188611010560", title: "baz-ketis" },
{ id: "1828976169320448", title: "baz-ziluwi" },
{ id: "4158848130613248", title: "baz-zev" },
],
},
},
});
```
## Providing custom resolvers
It is possible to create a custom resolver that can use the mock store to retrieve or update the stored mocks.
This can be useful for mocking resolvers where the arguments are important.
Here we want to make sure that when we resolve an author, we get the id we asked for:
```js
mock = new GraphQLMock({
typeDefs,
resolvers: (store) => ({
Query: {
author: (root, { id }) => store.get("Author", id),
},
}),
});
result = await mock.execute(authorQuery, { id: "42" });
expect(result, "to satisfy", {
data: {
author: {
id: "42",
firstName: "herubju",
lastName: "nocpebe",
email: "kelecse",
posts: [
{ id: "1828976169320448", title: "jeminode" },
{ id: "4158848130613248", title: "orimipon" },
],
},
},
});
```
See [Handling \*byId fields](https://www.graphql-tools.com/docs/mocking#handling-byid-fields) for more information.
## Creating a preconfigured mock
```js
class MyMock extends GraphQLMock {
constructor(mocks) {
super({
typeDefs,
mocks: [
{
Author: (chance) => ({
id: String(chance.natural()),
email: chance.email(),
posts: list(3),
}),
Post: (chance) => ({
id: String(chance.natural()),
title: `title-${chance.word()}`,
}),
},
mocks,
],
});
}
}
mock = new MyMock({
Author: (chance) => ({
id: "author-0",
firstName: "Jane",
lastName: "Doe",
}),
});
result = await mock.execute(authorQuery, { id: authorId });
expect(result, "to satisfy", {
data: {
author: {
firstName: "Jane",
lastName: "Doe",
email: "[email protected]",
posts: [
{ id: "6325555974635520", title: "title-ha" },
{ id: "308014672248832", title: "title-felsuh" },
],
},
},
});
```