From 84ef4b5422557fac193134b5a7cd648579f04c7f Mon Sep 17 00:00:00 2001
From: Alex Moon <alex.jared.moon@gmail.com>
Date: Sun, 2 May 2021 12:44:51 -0700
Subject: [PATCH] fix: correctly prefix sitemaps with pathPrefix

---
 .../src/__tests__/gatsby-node.js              | 38 +++++++++++++++++++
 .../gatsby-plugin-sitemap/src/gatsby-node.js  |  3 +-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/packages/gatsby-plugin-sitemap/src/__tests__/gatsby-node.js b/packages/gatsby-plugin-sitemap/src/__tests__/gatsby-node.js
index f2d68df47ffdf..d1138f26eb60c 100644
--- a/packages/gatsby-plugin-sitemap/src/__tests__/gatsby-node.js
+++ b/packages/gatsby-plugin-sitemap/src/__tests__/gatsby-node.js
@@ -155,4 +155,42 @@ describe(`gatsby-plugin-sitemap Node API`, () => {
       expect(page.url).toEqual(expect.stringContaining(prefix))
     })
   })
+
+  it(`should output modified paths to sitemap`, async () => {
+    const graphql = jest.fn()
+    graphql.mockResolvedValue({
+      data: {
+        site: {
+          siteMetadata: {
+            siteUrl: `http://dummy.url`,
+          },
+        },
+        allSitePage: {
+          nodes: [
+            {
+              path: `/page-1`,
+            },
+            {
+              path: `/page-2`,
+            },
+          ],
+        },
+      },
+    })
+    const prefix = `/test`
+    const subdir = `/subdir`
+    const options = {
+      output: subdir,
+    }
+    await onPostBuild(
+      { graphql, pathPrefix: prefix, reporter },
+      await schema.validateAsync(options)
+    )
+    expect(sitemap.simpleSitemapAndIndex.mock.calls[0][0].publicBasePath).toBe(
+      path.posix.join(prefix, subdir)
+    )
+    expect(sitemap.simpleSitemapAndIndex.mock.calls[0][0].destinationDir).toBe(
+      path.join(`public`, subdir)
+    )
+  })
 })
diff --git a/packages/gatsby-plugin-sitemap/src/gatsby-node.js b/packages/gatsby-plugin-sitemap/src/gatsby-node.js
index 3aeb81674b150..b295ecca12bad 100644
--- a/packages/gatsby-plugin-sitemap/src/gatsby-node.js
+++ b/packages/gatsby-plugin-sitemap/src/gatsby-node.js
@@ -84,10 +84,11 @@ exports.onPostBuild = async (
   }
 
   const sitemapWritePath = path.join(`public`, output)
+  const sitemapPublicPath = path.posix.join(pathPrefix, output)
 
   return simpleSitemapAndIndex({
     hostname: siteUrl,
-    publicBasePath: output,
+    publicBasePath: sitemapPublicPath,
     destinationDir: sitemapWritePath,
     sourceData: serializedPages,
     limit: entryLimit,