From 58c02009f3490797399ebef6ea1192b125838f1c Mon Sep 17 00:00:00 2001
From: Zoltan Kochan <z@kochan.io>
Date: Wed, 27 May 2020 00:37:17 +0300
Subject: [PATCH] fix: modules directory compatibility check

Always check the layout version first.
---
 .changeset/twelve-ladybugs-float.md                  |  5 +++++
 packages/get-context/src/checkCompatibility/index.ts | 12 ++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)
 create mode 100644 .changeset/twelve-ladybugs-float.md

diff --git a/.changeset/twelve-ladybugs-float.md b/.changeset/twelve-ladybugs-float.md
new file mode 100644
index 0000000000..9fe88cf938
--- /dev/null
+++ b/.changeset/twelve-ladybugs-float.md
@@ -0,0 +1,5 @@
+---
+"@pnpm/get-context": patch
+---
+
+When checking compatibility of the existing modules directory, start with the layout version. Otherwise, it may happen that some of the fields were renamed and other checks will fail.
diff --git a/packages/get-context/src/checkCompatibility/index.ts b/packages/get-context/src/checkCompatibility/index.ts
index 0d04d45274..8b2686d55e 100644
--- a/packages/get-context/src/checkCompatibility/index.ts
+++ b/packages/get-context/src/checkCompatibility/index.ts
@@ -13,11 +13,16 @@ export default function checkCompatibility (
     virtualStoreDir: string,
   }
 ) {
+  if (!modules.layoutVersion || modules.layoutVersion !== LAYOUT_VERSION) {
+    throw new ModulesBreakingChangeError({
+      modulesPath: opts.modulesDir,
+    })
+  }
   // Important: comparing paths with path.relative()
   // is the only way to compare paths correctly on Windows
   // as of Node.js 4-9
   // See related issue: https://github.com/pnpm/pnpm/issues/996
-  if (path.relative(modules.storeDir, opts.storeDir) !== '') {
+  if (!modules.storeDir || path.relative(modules.storeDir, opts.storeDir) !== '') {
     throw new UnexpectedStoreError({
       actualStorePath: opts.storeDir,
       expectedStorePath: modules.storeDir,
@@ -31,9 +36,4 @@ export default function checkCompatibility (
       modulesDir: opts.modulesDir,
     })
   }
-  if (!modules.layoutVersion || modules.layoutVersion !== LAYOUT_VERSION) {
-    throw new ModulesBreakingChangeError({
-      modulesPath: opts.modulesDir,
-    })
-  }
 }