Add ability to resolve references within raw fields (#10)

README.md

@@ -232,6 +232,20 @@ Remember to use the GraphiQL interface to help write the queries you need - it's
 
 Arrays and object types at the root of documents will get an additional "raw JSON" representation in a field called `_raw<FieldName>`. For instance, a field named `body` will be mapped to `_rawBody`. It's important to note that this is only done for top-level nodes (documents).
 
+Quite often, you'll want to replace reference fields (eg `_ref: '<documentId>'`, or `someField___NODE: '<documentId>'`), with the actual document that is referenced. This is done automatically for regular fields, but within raw fields, you have to explicitly enable this behavior, by using the field-level `resolveReferences` argument:
+
+```graphql
+{
+  allSanityProject {
+    edges {
+      node {
+        _rawTasks(resolveReferences: {maxDepth: 5})
+      }
+    }
+  }
+}
+```
+
 ## Portable Text / Block Content
 
 Rich text in Sanity is usually represented as [Portable Text](https://www.portabletext.org/) (previously known as "Block Content").

src/gatsby-node.ts

@@ -4,13 +4,19 @@ import * as through from 'through2'
 import {copy} from 'fs-extra'
 import {camelCase} from 'lodash'
 import {filter} from 'rxjs/operators'
-import {GraphQLJSON, GraphQLFieldConfig} from 'gatsby/graphql'
+import {
+  GraphQLJSON,
+  GraphQLFieldConfig,
+  GraphQLInt,
+  GraphQLInputObjectType,
+  GraphQLNonNull
+} from 'gatsby/graphql'
 import SanityClient = require('@sanity/client')
 import {GatsbyContext, GatsbyReporter, GatsbyNode, GatsbyOnNodeTypeContext} from './types/gatsby'
 import {SanityDocument} from './types/sanity'
 import {pump} from './util/pump'
 import {rejectOnApiError} from './util/rejectOnApiError'
-import {processDocument} from './util/normalize'
+import {processDocument, unprefixDraftId} from './util/normalize'
 import {getDocumentStream} from './util/getDocumentStream'
 import {getCacheKey, CACHE_KEYS} from './util/cache'
 import {removeSystemDocuments} from './util/removeSystemDocuments'
@@ -164,6 +170,16 @@ export const onPreExtractQueries = async (context: GatsbyContext, pluginConfig:
   await createTemporaryMockNodes(context, pluginConfig, stateCache)
 }
 
+const resolveReferencesConfig = new GraphQLInputObjectType({
+  name: 'SanityResolveReferencesConfiguration',
+  fields: {
+    maxDepth: {
+      type: new GraphQLNonNull(GraphQLInt),
+      description: 'Max depth to resolve references to'
+    }
+  }
+})
+
 export const setFieldsOnGraphQLNodeType = async (
   context: GatsbyContext & GatsbyOnNodeTypeContext,
   pluginConfig: PluginConfig
@@ -191,9 +207,15 @@ export const setFieldsOnGraphQLNodeType = async (
       const aliasName = '_' + camelCase(`raw ${field.aliasFor}`)
       acc[aliasName] = {
         type: GraphQLJSON,
-        resolve: (obj: {[key: string]: {}}) => {
-          const raw = `_${camelCase(`raw_data_${field.aliasFor}`)}`
-          return obj[raw] || obj[fieldName] || obj[aliasFor]
+        args: {
+          resolveReferences: {type: resolveReferencesConfig}
+        },
+        resolve: (obj: {[key: string]: {}}, args) => {
+          const raw = `_${camelCase(`raw_data_${field.aliasFor || fieldName}`)}`
+          const value = obj[raw] || obj[fieldName] || obj[aliasFor]
+          return args.resolveReferences
+            ? resolveReferences(value, 0, args.resolveReferences.maxDepth, context, pluginConfig)
+            : value
         }
       }
       return acc
@@ -204,15 +226,82 @@ export const setFieldsOnGraphQLNodeType = async (
     const aliasName = '_' + camelCase(`raw ${fieldName}`)
     acc[aliasName] = {
       type: GraphQLJSON,
-      resolve: (obj: {[key: string]: {}}) => {
-        const raw = `_${camelCase(`raw_data_${field.aliasFor}`)}`
-        return obj[raw] || obj[aliasName] || obj[fieldName]
+      args: {
+        resolveReferences: {type: resolveReferencesConfig}
+      },
+      resolve: (obj: {[key: string]: {}}, args) => {
+        const raw = `_${camelCase(`raw_data_${field.aliasFor || fieldName}`)}`
+        const value = obj[raw] || obj[aliasName] || obj[fieldName]
+        return args.resolveReferences
+          ? resolveReferences(value, 0, args.resolveReferences.maxDepth, context, pluginConfig)
+          : value
       }
     }
     return acc
   }, fields)
 }
 
+function resolveReferences(
+  obj: any,
+  depth: number,
+  maxDepth: number,
+  context: GatsbyContext,
+  pluginConfig: PluginConfig
+): any {
+  const {createNodeId, getNode} = context
+  const {overlayDrafts} = pluginConfig
+
+  if (Array.isArray(obj)) {
+    return depth <= maxDepth
+      ? obj.map(item => resolveReferences(item, depth + 1, maxDepth, context, pluginConfig))
+      : obj
+  }
+
+  if (obj === null || typeof obj !== 'object') {
+    return obj
+  }
+
+  if (typeof obj._ref === 'string') {
+    const id = obj._ref
+    const node = getNode(createNodeId(overlayDrafts ? unprefixDraftId(id) : id))
+    return node && depth <= maxDepth
+      ? resolveReferences(node, depth + 1, maxDepth, context, pluginConfig)
+      : obj
+  }
+
+  const initial: {[key: string]: any} = {}
+  return Object.keys(obj).reduce((acc, key) => {
+    const isGatsbyRef = key.endsWith('___NODE')
+    const isRawDataField = key.startsWith('_rawData')
+    let targetKey = isGatsbyRef && depth <= maxDepth ? key.slice(0, -7) : key
+
+    let value = obj[key]
+    if (isGatsbyRef && depth <= maxDepth) {
+      value = resolveGatsbyReference(obj[key], context)
+    }
+
+    value = resolveReferences(value, depth + 1, maxDepth, context, pluginConfig)
+
+    if (isRawDataField) {
+      targetKey = `_raw${key.slice(8)}`
+    }
+
+    acc[targetKey] = value
+    return acc
+  }, initial)
+}
+
+function resolveGatsbyReference(value: string | string[], context: GatsbyContext) {
+  const {getNode} = context
+  if (typeof value === 'string') {
+    return getNode(value)
+  } else if (Array.isArray(value)) {
+    return value.map(id => getNode(id))
+  } else {
+    throw new Error(`Unknown Gatsby node reference: ${value}`)
+  }
+}
+
 function validateConfig(config: PluginConfig, reporter: GatsbyReporter) {
   if (!config.projectId) {
     throw new Error('[sanity] `projectId` must be specified')

src/util/normalize.ts

@@ -77,7 +77,7 @@ export function processDocument(doc: SanityDocument, options: ProcessingOptions)
 }
 
 // `drafts.foo-bar` => `foo.bar`
-function unprefixDraftId(id: string) {
+export function unprefixDraftId(id: string) {
   return id.replace(/^drafts\./, '')
 }