feat(graphql): initial GraphQL source plugin (gridsome#482)

Closes gridsome#80

Author: jakedohm

packages/source-graphql/CHANGELOG.md

@@ -0,0 +1,68 @@
+# @gridsome/source-graphql
+
+> Pull a remote GraphQL schema in locally
+
+## Install
+
+- `yarn add @gridsome/source-graphql`
+- `npm install @gridsome/source-graphql`
+
+## Usage
+
+```js
+module.exports = {
+  plugins: [
+    {
+      use: '@gridsome/source-graphql',
+      options: {
+        url: 'https://example.com/api',
+        fieldName: 'puppies',
+        typeName: 'puppyTypes',
+
+        headers: {
+          Authorization: `Bearer ${process.env.AUTH_TOKEN}`,
+        },
+      },
+    },
+  ],
+}
+```
+
+## Options
+
+#### url
+
+- Type: `string` _required_
+
+The URL of a GraphQL API endpoint to request your schema from.
+
+#### fieldName
+
+- Type: `string` _required_
+
+The name that should be used to namespace your remote schema when it's merged in, so that it doesn't conflict with any local data.
+
+For instance, if you put "puppies" your remote schema's data will be available by querying like so:
+
+```
+query {
+  puppies {
+    helloWorld
+  }
+}
+```
+
+#### typeName
+
+- Type: `string`
+- Defaults: `fieldName`
+
+The prefix to be used for your imported schema's field types.
+
+#### headers
+
+- Type: `object`
+
+An object of headers to be passed along with your request to the API endpoint. This will generally be used to authenticate your request.
+
+**Note**: For safety, you should pass any sensitive tokens/passwords as environmental variables. To learn more, see the [Gridsome Docs on Environmental Variables](https://gridsome.org/docs/environment-variables/).

packages/source-graphql/README.md

@@ -0,0 +1,93 @@
+const { setContext } = require('apollo-link-context')
+const { HttpLink } = require('apollo-link-http')
+const {
+  introspectSchema,
+  makeRemoteExecutableSchema,
+  transformSchema,
+  RenameTypes
+} = require('graphql-tools')
+const fetch = require('node-fetch')
+
+const {
+  NamespaceUnderFieldTransform,
+  StripNonQueryTransform
+} = require(`./transforms`)
+
+class GraphQLSource {
+  static defaultOptions () {
+    return {
+      url: undefined,
+      fieldName: undefined,
+      typeName: undefined,
+      headers: {}
+    }
+  }
+
+  constructor (api, options) {
+    this.api = api
+    const { url, fieldName, headers } = options
+    let typeName = options.typeName
+
+    // Make sure all required props are passed
+
+    if (!url) {
+      throw new Error(`Missing url option.`)
+    }
+
+    if (!fieldName) {
+      throw new Error(`Missing fieldName option.`)
+    }
+
+    // If typeName isn't defined, default to fieldName
+
+    if (!typeName) {
+      typeName = fieldName
+    }
+
+    // Fetch schema, namespace it, and merge it into local schema
+    api.createSchema(async ({ addSchema, graphql }) => {
+      const remoteSchema = await this.getRemoteExecutableSchema(url, headers)
+      const namespacedSchema = await this.namespaceSchema(
+        remoteSchema,
+        fieldName,
+        typeName,
+        graphql
+      )
+
+      return namespacedSchema
+    })
+  }
+
+  async getRemoteExecutableSchema (url, headers) {
+    const http = new HttpLink({
+      uri: url,
+      fetch
+    })
+    const link = setContext((request, previousContext) => ({ headers })).concat(
+      http
+    )
+    const remoteSchema = await introspectSchema(link)
+    const remoteExecutableSchema = await makeRemoteExecutableSchema({
+      schema: remoteSchema,
+      link
+    })
+
+    return remoteExecutableSchema
+  }
+
+  async namespaceSchema (schema, fieldName, typeName, graphql) {
+    const namespacedSchema = transformSchema(schema, [
+      new StripNonQueryTransform(),
+      new RenameTypes(name => `${typeName}_${name}`),
+      new NamespaceUnderFieldTransform({
+        typeName,
+        fieldName,
+        graphql
+      })
+    ])
+
+    return namespacedSchema
+  }
+}
+
+module.exports = GraphQLSource

packages/source-graphql/index.js

@@ -0,0 +1,26 @@
+{
+  "version": "0.0.0",
+  "name": "@gridsome/source-graphql",
+  "description": "GraphQL source for Gridsome",
+  "homepage": "https://github.com/gridsome/gridsome/tree/master/packages/source-graphql#readme",
+  "repository": "https://github.com/gridsome/gridsome/tree/master/packages/source-graphql",
+  "main": "index.js",
+  "keywords": [
+    "gridsome",
+    "gridsome-plugin",
+    "gridsome-source"
+  ],
+  "dependencies": {
+    "apollo-link-context": "^1.0.17",
+    "apollo-link-http": "^1.5.14",
+    "graphql-tools": "^4.0.4",
+    "node-fetch": "^2.6.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "engines": {
+    "node": ">=8"
+  },
+  "devDependencies": {}
+}

packages/source-graphql/package.json

@@ -0,0 +1,77 @@
+const {
+  visitSchema,
+  VisitSchemaKind
+} = require(`graphql-tools/dist/transforms/visitSchema`)
+const {
+  createResolveType,
+  fieldMapToFieldConfigMap
+} = require(`graphql-tools/dist/stitching/schemaRecreation`)
+
+class NamespaceUnderFieldTransform {
+  constructor ({ typeName, fieldName, graphql }) {
+    this.typeName = typeName
+    this.fieldName = fieldName
+    this.graphql = graphql
+  }
+
+  transformSchema (schema) {
+    const { GraphQLObjectType, GraphQLSchema } = this.graphql
+
+    const query = schema.getQueryType()
+
+    let newQuery // eslint-disable-line
+    const nestedType = new GraphQLObjectType({
+      name: this.typeName,
+      fields: () =>
+        fieldMapToFieldConfigMap(
+          query.getFields(),
+          createResolveType(typeName => {
+            if (typeName === query.name) {
+              return newQuery
+            } else {
+              return schema.getType(typeName)
+            }
+          }),
+          true
+        )
+    })
+    newQuery = new GraphQLObjectType({
+      name: query.name,
+      fields: {
+        [this.fieldName]: {
+          type: nestedType,
+          resolve: (parent, args, context, info) => {
+            return {}
+          }
+        }
+      }
+    })
+    const typeMap = schema.getTypeMap()
+    const allTypes = Object.keys(typeMap)
+      .filter(name => name !== query.name)
+      .map(key => typeMap[key])
+
+    return new GraphQLSchema({
+      query: newQuery,
+      types: allTypes
+    })
+  }
+}
+
+class StripNonQueryTransform {
+  transformSchema (schema) {
+    return visitSchema(schema, {
+      [VisitSchemaKind.MUTATION] () {
+        return null
+      },
+      [VisitSchemaKind.SUBSCRIPTION] () {
+        return null
+      }
+    })
+  }
+}
+
+module.exports = {
+  NamespaceUnderFieldTransform,
+  StripNonQueryTransform
+}

packages/source-graphql/transforms.js

@@ -2206,7 +2206,33 @@ anymatch@^2.0.0:
     micromatch "^3.1.4"
     normalize-path "^2.1.1"
 
-apollo-link@^1.2.3:
+apollo-link-context@^1.0.17:
+  version "1.0.17"
+  resolved "https://registry.yarnpkg.com/apollo-link-context/-/apollo-link-context-1.0.17.tgz#439272cfb43ec1891506dd175ed907845b7de36c"
+  integrity sha512-W5UUfHcrrlP5uqJs5X1zbf84AMXhPZGAqX/7AQDgR6wY/7//sMGfJvm36KDkpIeSOElztGtM9z6zdPN1NbT41Q==
+  dependencies:
+    apollo-link "^1.2.11"
+    tslib "^1.9.3"
+
+apollo-link-http-common@^0.2.13:
+  version "0.2.13"
+  resolved "https://registry.yarnpkg.com/apollo-link-http-common/-/apollo-link-http-common-0.2.13.tgz#c688f6baaffdc7b269b2db7ae89dae7c58b5b350"
+  integrity sha512-Uyg1ECQpTTA691Fwx5e6Rc/6CPSu4TB4pQRTGIpwZ4l5JDOQ+812Wvi/e3IInmzOZpwx5YrrOfXrtN8BrsDXoA==
+  dependencies:
+    apollo-link "^1.2.11"
+    ts-invariant "^0.3.2"
+    tslib "^1.9.3"
+
+apollo-link-http@^1.5.14:
+  version "1.5.14"
+  resolved "https://registry.yarnpkg.com/apollo-link-http/-/apollo-link-http-1.5.14.tgz#ed6292248d1819ccd16523e346d35203a1b31109"
+  integrity sha512-XEoPXmGpxFG3wioovgAlPXIarWaW4oWzt8YzjTYZ87R4R7d1A3wKR/KcvkdMV1m5G7YSAHcNkDLe/8hF2nH6cg==
+  dependencies:
+    apollo-link "^1.2.11"
+    apollo-link-http-common "^0.2.13"
+    tslib "^1.9.3"
+
+apollo-link@^1.2.11, apollo-link@^1.2.3:
   version "1.2.11"
   resolved "https://registry.yarnpkg.com/apollo-link/-/apollo-link-1.2.11.tgz#493293b747ad3237114ccd22e9f559e5e24a194d"
   integrity sha512-PQvRCg13VduLy3X/0L79M6uOpTh5iHdxnxYuo8yL7sJlWybKRJwsv4IcRBJpMFbChOOaHY7Og9wgPo6DLKDKDA==
@@ -9283,6 +9309,11 @@ node-fetch@^2.3.0:
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.5.0.tgz#8028c49fc1191bba56a07adc6e2a954644a48501"
   integrity sha512-YuZKluhWGJwCcUu4RlZstdAxr8bFfOVHakc1mplwHkk8J+tqM1Y5yraYvIUpeX8aY7+crCwiELJq7Vl0o0LWXw==
 
+node-fetch@^2.6.0:
+  version "2.6.0"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.6.0.tgz#e633456386d4aa55863f676a7ab0daa8fdecb0fd"
+  integrity sha512-8dG4H5ujfvFiqDmVu9fQ5bOHUC15JMjMY/Zumv26oOvvVJjM67KF8koCWIabKQ1GJIa9r2mMZscBq/TbdOcmNA==
+
 node-gyp@^3.8.0:
   version "3.8.0"
   resolved "https://registry.yarnpkg.com/node-gyp/-/node-gyp-3.8.0.tgz#540304261c330e80d0d5edce253a68cb3964218c"