Optional list should not require the field to be set in the frontmatter #95

Author: schickling

packages/@contentlayer/source-files/src/__test__/fetchData/makeCacheItemFromFilePath.spec.ts

@@ -27,7 +27,7 @@ t.test('makeCacheItemFromFilePath', async (t) => {
     }
   })
 
-  t.test('b.md: missing required field', async (t) => {
+  t.test('b.md: missing required field: list of strings', async (t) => {
     const TestPost = defineDocumentType(() => ({
       name: 'TestPost',
       filePathPattern: `**/*.md`,
@@ -44,6 +44,23 @@ t.test('makeCacheItemFromFilePath', async (t) => {
     }
   })
 
+  t.test('b.md: missing optional field: list of strings', async (t) => {
+    const TestPost = defineDocumentType(() => ({
+      name: 'TestPost',
+      filePathPattern: `**/*.md`,
+      fields: {
+        tags: { type: 'list', of: { type: 'string' }, required: false },
+      },
+    }))
+
+    const { result } = await runTest({ documentTypes: [TestPost], contentDirPath, relativeFilePath: 'b.md' })
+
+    t.equal(result._tag, 'Right')
+    if (E.isRight(result)) {
+      t.ok(result.right.document)
+    }
+  })
+
   t.test('c.md: invalid frontmatter', async (t) => {
     const TestPost = defineDocumentType(() => ({
       name: 'TestPost',

packages/@contentlayer/source-files/src/fetchData/validateDocumentData.ts

@@ -185,9 +185,13 @@ const validateFieldData = ({
   O.Option<FetchDataError.IncompatibleFieldDataError | FetchDataError.ReferencedFileDoesNotExistError>
 > =>
   T.gen(function* ($) {
+    const dataIsNil = rawFieldData === undefined || rawFieldData === null
+    if (dataIsNil && fieldDef.isRequired === false) {
+      return O.none
+    }
+
     switch (fieldDef.type) {
       case 'list':
-        // TODO fix if optional
         return Array.isArray(rawFieldData)
           ? O.none
           : O.some(
@@ -197,7 +201,7 @@ const validateFieldData = ({
                 documentTypeName,
               }),
             )
-      // TODO also check for lists
+      // TODO also check for references in lists
       case 'reference':
         if (typeof rawFieldData === 'string') {
           const fullFilePath = filePathJoin(contentDirPath, rawFieldData)

packages/next-contentlayer/src/index.ts

@@ -4,7 +4,7 @@ import { runContentlayerBuild, runContentlayerDev } from './plugin.js'
 
 export type { NextConfig }
 
-type PluginOptions = {}
+export type PluginOptions = {}
 
 let devServerStarted = false