From 84e53e4b570d10e6f57877cb979f29a397063b9b Mon Sep 17 00:00:00 2001
From: Fela Maslen <felamaslen@gmail.com>
Date: Fri, 5 Jul 2024 11:34:51 +0100
Subject: [PATCH] fix: deduplicate fragments when generating persisted document
 hash (#342)

---
 .changeset/stale-plums-prove.md     |  5 +++++
 packages/graphqlsp/src/persisted.ts | 13 ++++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/stale-plums-prove.md

diff --git a/.changeset/stale-plums-prove.md b/.changeset/stale-plums-prove.md
new file mode 100644
index 00000000..c4a94f1f
--- /dev/null
+++ b/.changeset/stale-plums-prove.md
@@ -0,0 +1,5 @@
+---
+'@0no-co/graphqlsp': patch
+---
+
+Fixed duplicate fragments in persisted document hash generator
diff --git a/packages/graphqlsp/src/persisted.ts b/packages/graphqlsp/src/persisted.ts
index c9ba706f..e2629185 100644
--- a/packages/graphqlsp/src/persisted.ts
+++ b/packages/graphqlsp/src/persisted.ts
@@ -183,12 +183,15 @@ export const generateHashForDocument = (
       foundFilename,
       info
     ).combinedText;
-    fragments.forEach(fragmentDefinition => {
-      text = `${text}\n\n${print(fragmentDefinition)}`;
+    const deduplicatedFragments = fragments
+      .map(fragment => print(fragment))
+      .filter((fragment, index, array) => array.indexOf(fragment) === index);
+
+    deduplicatedFragments.forEach(fragmentDefinition => {
+      text = `${text}\n\n${fragmentDefinition}`;
     });
-    return createHash('sha256')
-      .update(print(parse(text)))
-      .digest('hex');
+    const fullText = print(parse(text));
+    return createHash('sha256').update(fullText).digest('hex');
   } else {
     const externalSource = getSource(info, foundFilename)!;
     const { fragments } = findAllCallExpressions(externalSource, info);