feat(gatsby): Allow specifying type on link extension (#16680)

gatsbyjs · Aug 19, 2019 · f9bbb55 · f9bbb55
1 parent a4c97e3
commit f9bbb55
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Showing 4 changed files with 99 additions and 4 deletions.
diff --git a/packages/gatsby/src/schema/extensions/__tests__/field-extensions.js b/packages/gatsby/src/schema/extensions/__tests__/field-extensions.js
@@ -38,6 +38,9 @@ describe(`GraphQL field extensions`, () => {
         internal: { type: `Test` },
         somedate: `2019-09-13`,
         otherdate: `2019-09-13`,
+        nested: {
+          onemoredate: `2019-09-26`,
+        },
       },
       {
         id: `test3`,
@@ -1564,6 +1567,95 @@ describe(`GraphQL field extensions`, () => {
       it.todo(`proxies to nested field on linked in node`)
     })
   })
+
+  it(`link extension accepts return type argument`, async () => {
+    dispatch(
+      createFieldExtension({
+        name: `reduce`,
+        args: {
+          to: `String!`,
+        },
+        extend(options, fieldConfig) {
+          return {
+            async resolve(source, args, context, info) {
+              const { getValueAt } = require(`../../../utils/get-value-at`)
+              const resolver =
+                fieldConfig.resolve || context.defaultFieldResolver
+              const fieldValue = await resolver(source, args, context, info)
+              if (fieldValue == null) return null
+              return getValueAt(fieldValue, options.to)
+            },
+          }
+        },
+      })
+    )
+    dispatch(
+      createTypes(`
+        type Test implements Node @dontInfer {
+          fieldFromParent: Date @link(from: "parent", on: "AnotherTest") @reduce(to: "date") @dateformat(formatString: "MM/DD/YYYY")
+        }
+        type AnotherTest implements Node @dontInfer {
+          fieldsFromChildren: [Date] @link(from: "children", on: "[Test!]!") @reduce(to: "somedate") @dateformat(formatString: "DD/MM/YYYY")
+          nestedFieldsFromChildren: [Date] @link(from: "children", on: "[Test!]!") @reduce(to: "nested.onemoredate") @dateformat(formatString: "DD/MM/YYYY")
+        }
+      `)
+    )
+    const query = `
+      {
+        allTest {
+          nodes {
+            id
+            fieldFromParent
+          }
+        }
+        allAnotherTest {
+          nodes {
+            id
+            fieldsFromChildren
+            nestedFieldsFromChildren
+          }
+        }
+      }
+    `
+    const results = await runQuery(query)
+    const expected = {
+      allTest: {
+        nodes: [
+          {
+            id: `test1`,
+            fieldFromParent: `01/01/2019`,
+          },
+          {
+            id: `test2`,
+            fieldFromParent: `Invalid date`,
+          },
+          {
+            id: `test3`,
+            fieldFromParent: null,
+          },
+          {
+            id: `test4`,
+            fieldFromParent: null,
+          },
+        ],
+      },
+      allAnotherTest: {
+        nodes: [
+          {
+            id: `test5`,
+            fieldsFromChildren: [`01/09/2019`],
+            nestedFieldsFromChildren: [`30/07/2019`],
+          },
+          {
+            id: `test6`,
+            fieldsFromChildren: [`13/09/2019`],
+            nestedFieldsFromChildren: [`26/09/2019`],
+          },
+        ],
+      },
+    }
+    expect(results).toEqual(expected)
+  })
 })
 
 const buildSchema = async () => {

diff --git a/packages/gatsby/src/schema/extensions/index.js b/packages/gatsby/src/schema/extensions/index.js
@@ -110,10 +110,12 @@ const builtInFieldExtensions = {
         defaultValue: `id`,
       },
       from: `String`,
+      on: `String`,
     },
-    extend(args, fieldConfig) {
+    extend(args, fieldConfig, schemaComposer) {
+      const type = args.on && schemaComposer.typeMapper.getWrapped(args.on)
       return {
-        resolve: link(args, fieldConfig),
+        resolve: link({ ...args, type }, fieldConfig),
       }
     },
   },
@@ -225,7 +227,7 @@ const processFieldExtensions = ({
           const prevFieldConfig = typeComposer.getFieldConfig(fieldName)
           typeComposer.extendField(
             fieldName,
-            extend(extensions[name], prevFieldConfig)
+            extend(extensions[name], prevFieldConfig, schemaComposer)
           )
         }
       })

diff --git a/packages/gatsby/src/schema/resolvers.js b/packages/gatsby/src/schema/resolvers.js
@@ -132,7 +132,7 @@ const link = (options = {}, fieldConfig) => async (
     return fieldValue
   }
 
-  const returnType = getNullableType(info.returnType)
+  const returnType = getNullableType(options.type || info.returnType)
   const type = getNamedType(returnType)
 
   if (options.by === `id`) {

diff --git a/packages/gatsby/src/utils/get-value-at.js b/packages/gatsby/src/utils/get-value-at.js
@@ -5,6 +5,7 @@ const getValueAt = (obj, selector) => {
 }
 
 const get = (obj, selectors) => {
+  if (Array.isArray(obj)) return getArray(obj, selectors)
   const [key, ...rest] = selectors
   const value = obj[key]
   if (!rest.length) return value