fix(gatsby-plugin-page-creator): Find nested files for knownCollections (#37762)

Author: rogermparent

packages/gatsby-plugin-page-creator/src/__tests__/fixtures/page-utils/collection-routes/index.tsx

@@ -0,0 +1,20 @@
+import { findCollectionPageFiles } from "../path-utils"
+import path from "path"
+
+describe(`findCollectionPageFiles`, () => {
+  it(`will find all and only the collection routes in a fixture`, async () => {
+    expect(
+      await findCollectionPageFiles(
+        path.join(__dirname, `fixtures`, `page-utils`, `collection-routes`)
+      )
+    ).toMatchInlineSnapshot(`
+      Array [
+        "{Other.extension}.js",
+        "{RootItem.name}.tsx",
+        "nested/{NestedItem.name}.tsx",
+        "nested/{NestedDirectoryOnlyItem}/edit.tsx",
+        "nested/{NestedDirectoryOnlyItem}/index.tsx",
+      ]
+    `)
+  })
+})

packages/gatsby-plugin-page-creator/src/__tests__/fixtures/page-utils/collection-routes/nested/{NestedDirectoryOnlyItem}/edit.tsx

@@ -28,6 +28,7 @@ import {
   getPluginInstance,
   ICreateAPageFromNodeArgs,
 } from "./tracked-nodes-state"
+import { findCollectionPageFiles } from "./path-utils"
 import { getCollectionRouteParams } from "./get-collection-route-params"
 import { reverseLookupParams } from "./extract-query"
 import { getMatchPath } from "gatsby-core-utils/match-path"
@@ -421,9 +422,7 @@ export async function onPluginInit(
   }
 
   try {
-    const pagesGlob = `**/**\\{*\\}**`
-
-    const files = await glob(pagesGlob, { cwd: pagesPath })
+    const files = await findCollectionPageFiles(pagesPath)
 
     if (files.length > 0) {
       trackFeatureIsUsed(`UnifiedRoutes:collection-page-builder`)

packages/gatsby-plugin-page-creator/src/__tests__/fixtures/page-utils/collection-routes/nested/{NestedDirectoryOnlyItem}/index.tsx

@@ -1,3 +1,5 @@
+import glob from "globby"
+
 // Regex created with: https://spec.graphql.org/draft/#sec-Names
 // First char only letter, underscore; rest letter, underscore, digit
 const extractModelRegex = /\{([a-zA-Z_][\w]*)\./
@@ -121,3 +123,11 @@ export function compose(
   return (filePart: string): string =>
     functions.reduce((value, fn) => fn(value), filePart)
 }
+
+// Use globby to find all page files with collection routes
+// We want to find all files in a given path where any segment includes text wrapped in curly braces
+// e.g. "{Collection.field}.tsx" and "{Collection.field}/nestedpage.tsx"
+export const pagesGlob = `**/**\\{*\\}**(/**)`
+export const findCollectionPageFiles = (
+  pagesPath: string
+): Promise<Array<string>> => glob(pagesGlob, { cwd: pagesPath })