From 843259e3ef06c1444f9f88919a3625800004f5e0 Mon Sep 17 00:00:00 2001
From: Peter van der Zee <209817+pvdz@users.noreply.github.com>
Date: Thu, 8 Oct 2020 13:34:44 +0200
Subject: [PATCH] perf(gatsby-plugin-page-creator): use set for tracking
 existing files (#27336)

* perf(gatsby-plugin-page-creator): use set for tracking existing files

* Also drop the now unused lodash dep
---
 .../gatsby-plugin-page-creator/src/gatsby-node.ts     | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/gatsby-plugin-page-creator/src/gatsby-node.ts b/packages/gatsby-plugin-page-creator/src/gatsby-node.ts
index d82bfa1f2460f..e4fb02b3db9ea 100644
--- a/packages/gatsby-plugin-page-creator/src/gatsby-node.ts
+++ b/packages/gatsby-plugin-page-creator/src/gatsby-node.ts
@@ -1,5 +1,4 @@
 import glob from "globby"
-import _ from "lodash"
 import systemPath from "path"
 import { sync as existsSync } from "fs-exists-cached"
 import {
@@ -67,17 +66,19 @@ Please pick a path to an existing directory.`)
     const pagesGlob = `**/*.{${exts}}`
 
     // Get initial list of files.
-    let files = await glob(pagesGlob, { cwd: pagesPath })
+    const files = await glob(pagesGlob, { cwd: pagesPath })
     files.forEach(file => {
       createPage(file, pagesDirectory, actions, ignore, graphql, reporter)
     })
 
+    const knownFiles = new Set(files)
+
     watchDirectory(
       pagesPath,
       pagesGlob,
       addedPath => {
         try {
-          if (!_.includes(files, addedPath)) {
+          if (!knownFiles.has(addedPath)) {
             createPage(
               addedPath,
               pagesDirectory,
@@ -86,7 +87,7 @@ Please pick a path to an existing directory.`)
               graphql,
               reporter
             )
-            files.push(addedPath)
+            knownFiles.add(addedPath)
           }
         } catch (e) {
           reporter.panic(
@@ -108,7 +109,7 @@ Please pick a path to an existing directory.`)
               })
             }
           })
-          files = files.filter(f => f !== removedPath)
+          knownFiles.delete(removedPath)
         } catch (e) {
           reporter.panic(
             e.message.startsWith(`PageCreator`)