From 97106f6b8f79a8ae26aefc5ec601b5918cdf5777 Mon Sep 17 00:00:00 2001
From: Vladimir <sheremet.va@icloud.com>
Date: Fri, 10 Jun 2022 10:10:02 +0300
Subject: [PATCH] fix: skip writing snap file, if content didn't change (#1456)

* fix: skip writing snap file, if content didn't change

* chore: cleanup
---
 packages/vitest/src/integrations/snapshot/port/utils.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/packages/vitest/src/integrations/snapshot/port/utils.ts b/packages/vitest/src/integrations/snapshot/port/utils.ts
index f05e0398adbb..a2fc5b2e5a1b 100644
--- a/packages/vitest/src/integrations/snapshot/port/utils.ts
+++ b/packages/vitest/src/integrations/snapshot/port/utils.ts
@@ -151,10 +151,16 @@ export async function saveSnapshotFile(
       key => `exports[${printBacktickString(key)}] = ${printBacktickString(normalizeNewlines(snapshotData[key]))};`,
     )
 
+  const content = `${writeSnapshotVersion()}\n\n${snapshots.join('\n\n')}\n`
+  const skipWriting = fs.existsSync(snapshotPath) && (await fsp.readFile(snapshotPath, 'utf8')) === content
+
+  if (skipWriting)
+    return
+
   ensureDirectoryExists(snapshotPath)
   await fsp.writeFile(
     snapshotPath,
-    `${writeSnapshotVersion()}\n\n${snapshots.join('\n\n')}\n`,
+    content,
     'utf-8',
   )
 }