fix(gatsby): Allow "gatsby-node" directory for Parcel Compilation

packages/gatsby/src/utils/parcel/__tests__/compile-gatsby-files.ts

@@ -17,6 +17,7 @@ const dir = {
   tsOnlyInLocal: `${__dirname}/fixtures/ts-only-in-local-plugin`,
   misnamedJS: `${__dirname}/fixtures/misnamed-js`,
   misnamedTS: `${__dirname}/fixtures/misnamed-ts`,
+  gatsbyNodeAsDirectory: `${__dirname}/fixtures/gatsby-node-as-directory`,
 }
 
 jest.setTimeout(15000)
@@ -176,6 +177,30 @@ describe(`gatsby file compilation`, () => {
   })
 })
 
+describe(`gatsby-node directory is allowed`, () => {
+  beforeAll(async () => {
+    process.chdir(dir.gatsbyNodeAsDirectory)
+    await remove(`${dir.gatsbyNodeAsDirectory}/.cache`)
+  })
+  beforeEach(() => {
+    reporterPanicMock.mockClear()
+  })
+  it(`should not panic on gatsby-node dir`, async () => {
+    await compileGatsbyFiles(dir.gatsbyNodeAsDirectory)
+    expect(reporterPanicMock).not.toHaveBeenCalled()
+  })
+
+  it(`should compile gatsby-node file and its dir files`, async () => {
+    const compiledGatsbyNode = await readFile(
+      `${dir.gatsbyNodeAsDirectory}/.cache/compiled/gatsby-node.js`,
+      `utf-8`
+    )
+
+    expect(compiledGatsbyNode).toContain(`I am working!`)
+    expect(reporterPanicMock).not.toHaveBeenCalled()
+  })
+})
+
 describe(`misnamed gatsby-node files`, () => {
   beforeEach(() => {
     reporterPanicMock.mockClear()

packages/gatsby/src/utils/parcel/__tests__/fixtures/gatsby-node-as-directory/gatsby-node.ts

@@ -0,0 +1,2 @@
+import { onPreInit } from "./gatsby-node/on-pre-init"
+export { onPreInit }

packages/gatsby/src/utils/parcel/__tests__/fixtures/gatsby-node-as-directory/gatsby-node/on-pre-init.ts

@@ -0,0 +1,6 @@
+import { GatsbyNode } from "gatsby"
+import { working } from "../../utils/say-what-ts"
+
+export const onPreInit: GatsbyNode["onPreInit"] = ({ reporter }) => {
+  reporter.info(working)
+}

packages/gatsby/src/utils/parcel/compile-gatsby-files.ts

@@ -61,11 +61,17 @@ export async function compileGatsbyFiles(
   retry: number = 0
 ): Promise<void> {
   try {
+    const gatsbyNodeName = `gatsby-node`
+
     // Check for gatsby-node.jsx and gatsby-node.tsx (or other misnamed variations)
-    const files = await readdir(siteRoot)
+    // We want to filter out directory names so we can use "withFileTypes"
+    // With "withFileTypes" the array will contain <fs.Dirent> objects
+    const filesAndDirectories = await readdir(siteRoot, { withFileTypes: true })
+    const files = filesAndDirectories
+      .filter(i => !i.isDirectory())
+      .map(i => i.name)
 
     let nearMatch = ``
-    const configName = `gatsby-node`
 
     for (const file of files) {
       if (nearMatch) {
@@ -82,7 +88,8 @@ export async function compileGatsbyFiles(
         break
       }
 
-      if (isNearMatch(name, configName, 3)) {
+      // Check for likely misnamed files
+      if (isNearMatch(name, gatsbyNodeName, 3)) {
         nearMatch = file
       }
     }
@@ -93,7 +100,7 @@ export async function compileGatsbyFiles(
       reporter.panic({
         id: `10128`,
         context: {
-          configName,
+          configName: gatsbyNodeName,
           nearMatch,
           isTSX,
         },