Add support for Graphql file upload

packages/openapi-to-graphql/README.md

@@ -131,6 +131,10 @@ For example, let's say that there was a library API that would allow you to get
 
 Notice that the slashes in the path `/favoriteBooks/{name}` must be escaped with `~1` and that you can compose parameter values with different [runtime expressions](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#runtimeExpression) using brackets.
 
+### File Uploads
+
+Support for file uploads through GraphQL is implemented based on the spec defined [here](https://github.com/jaydenseric/graphql-multipart-request-spec), through the module [`graphql-upload`](https://github.com/jaydenseric/graphql-upload). This requires that to opt-in for file uploads, it is required that a GraphQL client that provides support for the spec is used, additionally, on the Graphql Server the util method `processRequest` provided by the module `graphql-upload` is integrated to format the received request body to match the expectations for the spec.
+
 ### Options
 
 The `createGraphQLSchema` function takes an optional `options` object as a second argument:
@@ -183,6 +187,8 @@ Resolver options:
 
 - `customSubscriptionResolvers` (type: `object`, default: `{}`): If the `createSubscriptionsFromCallbacks` is enabled, OpenAPI-to-GraphQL will generate Subscription fields. This option allows users to provide custom resolver and subscribe functions to be used in place of said ones created by OpenAPI-to-GraphQL. The field that the custom resolver and subscribe functions will affect is identifed first by the [title](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#infoObject) of the OAS, then the [path](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#paths-object) of the operation, and lastly the [method](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#path-item-object) of the operation. The resolver is provided via the `resolver` field and the publish function is provided via the `publish` field. The `customSubscriptionResolvers` object is thus a quadruply nested object where the outer key is the title, followed by the path, then the method, and lastly either `resolver` or `publish` which points to the [resolver function](https://graphql.org/learn/execution/#root-fields-resolvers) itself or publish function. See the [Subscriptions tutorial](./docs/subscriptions.md) for more information. _Note: Because the arguments are provided by the GraphQL interface, they may look different from the [parameters](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#parameterObject) defined by the OAS. For example, they will have [sanitized](https://github.com/IBM/openapi-to-graphql#characteristics) names. The [request body](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#requestBodyObject) will also be contained in the arguments as an [input object type](https://graphql.org/graphql-js/mutations-and-input-types/)._
 
+- `fileUploadOptions` (type: `object`, default: `{}`): This options allows users to provide custom options for the form data object that will be used to process requests to endpoints that require a multipart request body, provided through the [`form-data` module](https://github.com/form-data/form-data)
+
 ***
 
 Authentication options:

packages/openapi-to-graphql/package.json

@@ -84,9 +84,11 @@
     "cross-fetch": "^3.1.4",
     "debug": "^4.2.0",
     "deep-equal": "^2.0.5",
+    "form-data": "^4.0.0",
     "form-urlencoded": "^6.0.4",
     "graphql-scalars": "^1.10.0",
     "graphql-subscriptions": "^1.1.0",
+    "graphql-upload": "^13.0.0",
     "json-ptr": "^2.2.0",
     "jsonpath-plus": "^6.0.1",
     "oas-validator": "^5.0.2",
@@ -102,6 +104,7 @@
   "devDependencies": {
     "@types/deep-equal": "^1.0.1",
     "@types/graphql": "^14.0.3",
+    "@types/graphql-upload": "^8.0.7",
     "@types/jest": "^26.0.14",
     "@types/node": "^16.3.3",
     "@types/url-join": "^4.0.1",
@@ -119,6 +122,7 @@
     "isomorphic-git": "^1.9.2",
     "jest": "^27.0.6",
     "js-yaml": "^4.1.0",
+    "memfs": "^3.4.0",
     "mqemitter": "^4.4.0",
     "mqtt": "^4.2.1",
     "nodemon": "^2.0.12",

packages/openapi-to-graphql/src/index.ts

@@ -36,7 +36,8 @@ import {
   InternalOptions,
   Report,
   ConnectOptions,
-  RequestOptions
+  RequestOptions,
+  FileUploadOptions
 } from './types/options'
 import { Oas3 } from './types/oas3'
 import { Oas2 } from './types/oas2'
@@ -112,6 +113,7 @@ const DEFAULT_OPTIONS: InternalOptions<any, any, any> = {
   requestOptions: {},
   customResolvers: {},
   customSubscriptionResolvers: {},
+  fileUploadOptions: {},
 
   // Authentication options
   viewer: true,
@@ -193,6 +195,7 @@ export function translateOpenAPIToGraphQL<TSource, TContext, TArgs>(
     headers,
     qs,
     requestOptions,
+    fileUploadOptions,
     connectOptions,
     baseUrl,
     customResolvers,
@@ -234,6 +237,7 @@ export function translateOpenAPIToGraphQL<TSource, TContext, TArgs>(
     headers,
     qs,
     requestOptions,
+    fileUploadOptions,
     connectOptions,
     baseUrl,
     customResolvers,
@@ -477,6 +481,7 @@ function addQueryFields<TSource, TContext, TArgs>({
     singularNames,
     baseUrl,
     requestOptions,
+      fileUploadOptions,
     connectOptions,
     fetch
   } = options
@@ -486,6 +491,7 @@ function addQueryFields<TSource, TContext, TArgs>({
     baseUrl,
     data,
     requestOptions,
+    fileUploadOptions,
     connectOptions,
     fetch
   )
@@ -654,6 +660,7 @@ function addMutationFields<TSource, TContext, TArgs>({
     singularNames,
     baseUrl,
     requestOptions,
+      fileUploadOptions,
     connectOptions,
     fetch
   } = options
@@ -663,6 +670,7 @@ function addMutationFields<TSource, TContext, TArgs>({
     baseUrl,
     data,
     requestOptions,
+    fileUploadOptions,
     connectOptions,
     fetch
   )
@@ -802,13 +810,14 @@ function addSubscriptionFields<TSource, TContext, TArgs>({
   options: InternalOptions<TSource, TContext, TArgs>
   data: PreprocessingData<TSource, TContext, TArgs>
 }) {
-  const { baseUrl, requestOptions, connectOptions, fetch } = options
+  const { baseUrl, requestOptions, connectOptions, fetch, fileUploadOptions } = options
 
   const field = getFieldForOperation(
     operation,
     baseUrl,
     data,
     requestOptions,
+    fileUploadOptions,
     connectOptions,
     fetch
   )
@@ -912,6 +921,7 @@ function getFieldForOperation<TSource, TContext, TArgs>(
   baseUrl: string,
   data: PreprocessingData<TSource, TContext, TArgs>,
   requestOptions: Partial<RequestOptions<TSource, TContext, TArgs>>,
+  fileUploadOptions: FileUploadOptions,
   connectOptions: ConnectOptions,
   fetch: typeof crossFetch
 ): GraphQLFieldConfig<TSource, TContext | SubscriptionContext, TArgs> {
@@ -978,6 +988,7 @@ function getFieldForOperation<TSource, TContext, TArgs>(
       data,
       baseUrl,
       requestOptions,
+      fileUploadOptions,
       fetch
     })
 

packages/openapi-to-graphql/src/oas_3_tools.ts

@@ -473,7 +473,9 @@ export function getSchemaTargetGraphQLType<TSource, TContext, TArgs>(
   if (typeof schema.format === 'string') {
     if (schema.type === 'integer' && schema.format === 'int64') {
       return TargetGraphQLType.bigint
-
+      // CASE: file upload
+    } else if (schema.type === 'string' && schema.format === 'binary') {
+      return TargetGraphQLType.upload
       // CASE: id
     } else if (
       schema.type === 'string' &&
@@ -840,7 +842,8 @@ export function getRequestSchemaAndNames(
         if (
           payloadContentType === 'application/json' ||
           payloadContentType === '*/*' ||
-          payloadContentType === 'application/x-www-form-urlencoded'
+          payloadContentType === 'application/x-www-form-urlencoded' ||
+            payloadContentType === 'multipart/form-data'
         ) {
           // Name extracted from a reference, if applicable
           let fromRef: string

packages/openapi-to-graphql/src/resolver_builder.ts

@@ -13,23 +13,27 @@ import { ConnectOptions } from './types/options'
 import { TargetGraphQLType, Operation } from './types/operation'
 import { SubscriptionContext } from './types/graphql'
 import { PreprocessingData } from './types/preprocessing_data'
-import { RequestOptions } from './types/options'
+import { RequestOptions, FileUploadOptions } from './types/options'
 import crossFetch from 'cross-fetch'
+import { FileUpload } from 'graphql-upload'
 
 // Imports:
+import stream from 'stream'
 import * as Oas3Tools from './oas_3_tools'
 import { JSONPath } from 'jsonpath-plus'
 import { debug } from 'debug'
 import { GraphQLError, GraphQLFieldResolver } from 'graphql'
 import formurlencoded from 'form-urlencoded'
 import { PubSub } from 'graphql-subscriptions'
 import urljoin from 'url-join'
+import FormData from 'form-data'
 
 const pubsub = new PubSub()
 
 const translationLog = debug('translation')
 const httpLog = debug('http')
 const pubsubLog = debug('pubsub')
+const uploadLog = debug('fileUpload')
 
 // OAS runtime expression reference locations
 const RUNTIME_REFERENCES = ['header.', 'query.', 'path.', 'body']
@@ -57,6 +61,7 @@ type GetResolverParams<TSource, TContext, TArgs> = {
   data: PreprocessingData<TSource, TContext, TArgs>
   baseUrl?: string
   requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>>
+  fileUploadOptions?: FileUploadOptions
   fetch: typeof crossFetch
 }
 
@@ -323,13 +328,14 @@ export function getPublishResolver<TSource, TContext, TArgs>({
  * If the operation type is Query or Mutation, create and return a resolver
  * function that performs API requests for the given GraphQL query
  */
-export function getResolver<TSource, TContext, TArgs>({
+export function getResolver<TSource, TContext, TArgs> ({
   operation,
   argsFromLink = {},
   payloadName,
   data,
   baseUrl,
   requestOptions,
+    fileUploadOptions,
   fetch
 }: GetResolverParams<TSource, TContext, TArgs>): GraphQLFieldResolver<
   TSource & OpenAPIToGraphQLSource<TSource, TContext, TArgs>,
@@ -554,6 +560,7 @@ export function getResolver<TSource, TContext, TArgs>({
      * GraphQL produces sanitized payload names, so we have to sanitize before
      * lookup here
      */
+    let form
     resolveData.usedPayload = undefined
     if (typeof payloadName === 'string') {
       // The option genericPayloadArgName will change the payload name to "requestBody"
@@ -572,6 +579,56 @@ export function getResolver<TSource, TContext, TArgs>({
         rawPayload = formurlencoded(
           Oas3Tools.desanitizeObjectKeys(args[sanePayloadName], data.saneMap)
         )
+      } else if (operation.payloadContentType === 'multipart/form-data') {
+        form = new FormData(fileUploadOptions)
+
+        const formFieldsPayloadEntries = Object.entries(args[sanePayloadName]);
+
+        (await Promise.all(formFieldsPayloadEntries.map(([_, v]) => v)))
+            .forEach((fieldValue, idx) => {
+              const fieldName = formFieldsPayloadEntries[idx][0]
+
+              if (typeof fieldValue === 'object' && Boolean((fieldValue as Partial<FileUpload>).createReadStream)) {
+                const uploadingFile = fieldValue as FileUpload
+                const originalFileStream = uploadingFile.createReadStream()
+                const filePassThrough = new stream.PassThrough()
+
+                originalFileStream.on('readable', function () {
+                  let data
+                  // tslint:disable-next-line:no-conditional-assignment
+                  while (data = this.read()) {
+                    const canReadNext = filePassThrough.write(data)
+                    if (!canReadNext) {
+                      this.pause()
+                      filePassThrough.once('drain', () => this.resume())
+                    }
+                  }
+                })
+
+                originalFileStream.on('error', () => {
+                  uploadLog('Encountered an error while uploading the file %s', uploadingFile.filename)
+                })
+
+                originalFileStream.on('end', () => {
+                  uploadLog('Upload for received file %s completed', uploadingFile.filename)
+                  filePassThrough.end()
+                })
+
+                uploadLog('Queuing upload for received file %s', uploadingFile.filename)
+
+                form.append(fieldName, filePassThrough, {
+                  filename: uploadingFile.filename,
+                  contentType: uploadingFile.mimetype
+                })
+              } else if (typeof fieldValue !== 'string') {
+                // handle all other primitives that aren't strings as strings the way the web server would expect it
+                form.append(fieldName, JSON.stringify(fieldValue))
+              } else {
+                form.append(fieldName, fieldValue)
+              }
+            })
+
+        rawPayload = form
       } else {
         // Payload is not an object
         rawPayload = args[sanePayloadName]
@@ -598,6 +655,13 @@ export function getResolver<TSource, TContext, TArgs>({
         if (typeof headers === 'object') {
           Object.assign(options.headers, headers)
         }
+
+        if (form) {
+          Object.assign(options.headers, form.getHeaders())
+          // when is form, remove default content type and leave computation of content-type header to fetch
+          // see https://github.com/github/fetch/issues/505#issuecomment-293064470
+          delete options.headers['content-type']
+        }
       }
 
       // Query string:

packages/openapi-to-graphql/src/schema_builder.ts

@@ -36,6 +36,7 @@ import {
   GraphQLInputType,
   GraphQLInputFieldConfigMap
 } from 'graphql'
+import { GraphQLUpload } from 'graphql-upload'
 
 // Imports:
 import { GraphQLBigInt, GraphQLJSON } from 'graphql-scalars'
@@ -222,6 +223,10 @@ export function getGraphQLType<TSource, TContext, TArgs>({
     case TargetGraphQLType.bigint:
       def.graphQLType = GraphQLBigInt
       return def.graphQLType
+
+    case TargetGraphQLType.upload:
+      def.graphQLType = GraphQLUpload
+      return def.graphQLType
   }
 }
 
@@ -780,6 +785,7 @@ function createFields<TSource, TContext, TArgs>({
             data,
             baseUrl: data.options.baseUrl,
             requestOptions: data.options.requestOptions,
+            fileUploadOptions: data.options.fileUploadOptions,
             fetch
           })
 

packages/openapi-to-graphql/src/types/operation.ts

@@ -38,6 +38,7 @@ export enum TargetGraphQLType {
   boolean = 'boolean',
   id = 'id',
   bigint = 'bigint',
+  upload = 'upload',
 
   // JSON
   json = 'json',

packages/openapi-to-graphql/src/types/options.ts

@@ -7,6 +7,7 @@
 import { GraphQLOperationType, SubscriptionContext } from './graphql'
 import { GraphQLFieldResolver, GraphQLResolveInfo } from 'graphql'
 import crossFetch from 'cross-fetch'
+import FormData from 'form-data'
 
 /**
  * Type definition of the options that users can pass to OpenAPI-to-GraphQL.
@@ -76,6 +77,17 @@ export type RequestOptions<TSource, TContext, TArgs> = Omit<
   qs?: Record<string, string>
 }
 
+/**
+ * We use the form-data library to prepare multipart requests within the resolver API calls,
+ * also it provides support for handling file as streams this way the file upload has a minimal memory footprint,
+ * unlike the situation where the entire file in memory initially.
+ *
+ * Provides accommodation to allow overrides or add options for how the form data representation for multipart requests is generated
+ *
+ * Based on: https://github.com/form-data/form-data#custom-options
+ */
+export type FileUploadOptions = ConstructorParameters<typeof FormData>[0]
+
 export type Options<TSource, TContext, TArgs> = Partial<
   InternalOptions<TSource, TContext, TArgs>
 >
@@ -275,6 +287,14 @@ export type InternalOptions<TSource, TContext, TArgs> = {
     resolve: GraphQLFieldResolver<TSource, TContext, TArgs>
   }>
 
+  /**
+   * Allows one to define config for the form data that will be used in streaming
+   * the uploaded file from the client to the intending endpoint
+   *
+   * Based on https://github.com/form-data/form-data#custom-options
+   */
+  fileUploadOptions?: FileUploadOptions
+
   // Authentication options
 
   /**