From f20de2e04fb5873058865c220ff2590c1057a368 Mon Sep 17 00:00:00 2001
From: Evan Barger <epbarger@gmail.com>
Date: Mon, 8 Mar 2021 18:27:18 -0500
Subject: [PATCH 1/2] Remove post-build.sh - instead use onPostBuild to clean
 up _redirects

Former-commit-id: ed4e09dd09f31540b7530603ca2f6c04b1f68e6d
---
 gatsby-node.js                     | 17 +++++++++++++++++
 package.json                       |  2 +-
 scripts/post-build.sh              |  8 --------
 src/constants/gatsby-node-utils.js | 18 ++++++++++++++++++
 4 files changed, 36 insertions(+), 9 deletions(-)
 delete mode 100644 scripts/post-build.sh

diff --git a/gatsby-node.js b/gatsby-node.js
index 2e1ff8415df..57624d88202 100644
--- a/gatsby-node.js
+++ b/gatsby-node.js
@@ -23,6 +23,8 @@ const {
   findPrevNextNavNodes,
   configureRedirects,
   configureLegacyRedirects,
+  readFile,
+  writeFile,
 } = require('./src/constants/gatsby-node-utils.js');
 
 const isBuild = process.env.NODE_ENV === 'production';
@@ -412,3 +414,18 @@ exports.onPreBootstrap = () => {
                                                                                                                    
   `);
 };
+
+exports.onPostBuild = async ({ reporter, pathPrefix }) => {
+  const originalRedirects = await readFile('public/_redirects');
+
+  // filter out legacyRedirects that are loaded via nginx, not netlify
+  let filteredRedirects = originalRedirects
+    .split('\n')
+    .filter((line) => !line.startsWith(`${pathPrefix}/edb-docs/`))
+    .join('\n');
+
+  await writeFile(
+    'public/_redirects',
+    `${filteredRedirects}\n\n# Netlify pathPrefix path rewrite\n${pathPrefix}/*  /:splat  200`,
+  );
+};
diff --git a/package.json b/package.json
index 701dd8d676f..5bfb9fb440a 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "develop": "gatsby develop",
     "config-sources": "python3 scripts/source/config_sources.py",
     "format": "prettier --write src/**/*.js gatsby-*.js",
-    "build": "gatsby build --prefix-paths && bash scripts/post-build.sh",
+    "build": "gatsby build --prefix-paths",
     "serve-build": "gatsby serve --prefix-paths",
     "update-icons": "git submodule update --init --remote && node scripts/createIconTypes.js && node scripts/createIconNames.js",
     "build-pdf": "python3 scripts/pdf/generate_pdf.py",
diff --git a/scripts/post-build.sh b/scripts/post-build.sh
deleted file mode 100644
index d903e459964..00000000000
--- a/scripts/post-build.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/bin/sh
-
-echo "post-build script starting"
-if test -f "public/_redirects"; then
-  echo "writing path prefix to public/_redirects"
-  printf "\n\n/docs/*  /:splat  200" >> public/_redirects
-fi
-echo "post-build script complete"
diff --git a/src/constants/gatsby-node-utils.js b/src/constants/gatsby-node-utils.js
index 17b1386c69a..ef6d0950181 100644
--- a/src/constants/gatsby-node-utils.js
+++ b/src/constants/gatsby-node-utils.js
@@ -1,3 +1,5 @@
+const fs = require('fs');
+
 const sortVersionArray = (versions) => {
   return versions
     .map((version) => version.replace(/\d+/g, (n) => +n + 100000))
@@ -308,6 +310,20 @@ const configureLegacyRedirects = ({
   });
 };
 
+const readFile = (filePath) =>
+  new Promise(function (resolve, reject) {
+    fs.readFile(filePath, 'utf8', function (err, data) {
+      err ? reject(err) : resolve(data);
+    });
+  });
+
+const writeFile = (filePath, data) =>
+  new Promise(function (resolve, reject) {
+    fs.writeFile(filePath, data, function (err) {
+      err ? reject(err) : resolve();
+    });
+  });
+
 module.exports = {
   sortVersionArray,
   replacePathVersion,
@@ -325,4 +341,6 @@ module.exports = {
   findPrevNextNavNodes,
   configureRedirects,
   configureLegacyRedirects,
+  readFile,
+  writeFile,
 };

From be48fcc5876950086205d8592d79f929fb322ff3 Mon Sep 17 00:00:00 2001
From: Evan Barger <epbarger@gmail.com>
Date: Tue, 9 Mar 2021 12:40:34 -0500
Subject: [PATCH 2/2] Add warning if no filtering happens

Former-commit-id: 335ba169dfe39e8ee73d5da194febca2a96a9b50
---
 gatsby-node.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gatsby-node.js b/gatsby-node.js
index 57624d88202..d77f483bffd 100644
--- a/gatsby-node.js
+++ b/gatsby-node.js
@@ -424,6 +424,10 @@ exports.onPostBuild = async ({ reporter, pathPrefix }) => {
     .filter((line) => !line.startsWith(`${pathPrefix}/edb-docs/`))
     .join('\n');
 
+  if (filteredRedirects.length === originalRedirects.length) {
+    reporter.warn('no redirects were filtered out, did something change?');
+  }
+
   await writeFile(
     'public/_redirects',
     `${filteredRedirects}\n\n# Netlify pathPrefix path rewrite\n${pathPrefix}/*  /:splat  200`,