From 52dd1146b59f17d6cc56ae90c58e5c0660e08806 Mon Sep 17 00:00:00 2001
From: DmitryScaletta <DmitryScaletta@users.noreply.github.com>
Date: Sun, 12 Nov 2023 16:21:52 +0300
Subject: [PATCH 1/4] Don't load submodules with not installed optional
 dependencies

See: https://github.com/metarhia/impress/issues/1937
---
 lib/deps.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/lib/deps.js b/lib/deps.js
index 81fa996a..1cccbef4 100644
--- a/lib/deps.js
+++ b/lib/deps.js
@@ -54,8 +54,16 @@ const loadModule = (name) => {
   const subKeys = Object.keys(pkg.exports).map((key) => key.substring(2));
   const subNames = subKeys.filter(validSubmodules);
   for (const subName of subNames) {
-    const sub = appRequire(name + '/' + subName);
-    lib[subName] = sub;
+    try {
+      const sub = appRequire(name + '/' + subName);
+      lib[subName] = sub;
+    } catch (e) {
+      if (e.message.startsWith("Cannot find module '")) {
+        const moduleName = e.message.substring(20, e.message.indexOf("'\n"));
+        const optional = pkg.peerDependenciesMeta?.[moduleName].optional;
+        if (optional) continue; else throw e;
+      }
+    }
   }
   return lib;
 };

From 095c9288f5fdc2911eaa082bfaf3c99d590e7062 Mon Sep 17 00:00:00 2001
From: DmitryScaletta <DmitryScaletta@users.noreply.github.com>
Date: Sun, 12 Nov 2023 16:26:31 +0300
Subject: [PATCH 2/4] Skip submodules if they have already been loaded as a
 part of main module

See: https://github.com/metarhia/impress/issues/1938
---
 lib/deps.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/deps.js b/lib/deps.js
index 1cccbef4..b343ebd4 100644
--- a/lib/deps.js
+++ b/lib/deps.js
@@ -56,12 +56,14 @@ const loadModule = (name) => {
   for (const subName of subNames) {
     try {
       const sub = appRequire(name + '/' + subName);
+      if (lib[subName] && lib[subName] === sub[subName]) continue;
       lib[subName] = sub;
     } catch (e) {
       if (e.message.startsWith("Cannot find module '")) {
         const moduleName = e.message.substring(20, e.message.indexOf("'\n"));
         const optional = pkg.peerDependenciesMeta?.[moduleName].optional;
-        if (optional) continue; else throw e;
+        if (optional) continue;
+        else throw e;
       }
     }
   }

From 3377c945d16643278257d7f2bd5f6e905676c4dc Mon Sep 17 00:00:00 2001
From: DmitryScaletta <DmitryScaletta@users.noreply.github.com>
Date: Sun, 12 Nov 2023 17:04:41 +0300
Subject: [PATCH 3/4] Fix checking whether a module is optional

---
 lib/deps.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/deps.js b/lib/deps.js
index b343ebd4..94865097 100644
--- a/lib/deps.js
+++ b/lib/deps.js
@@ -61,7 +61,7 @@ const loadModule = (name) => {
     } catch (e) {
       if (e.message.startsWith("Cannot find module '")) {
         const moduleName = e.message.substring(20, e.message.indexOf("'\n"));
-        const optional = pkg.peerDependenciesMeta?.[moduleName].optional;
+        const optional = pkg.peerDependenciesMeta?.[moduleName]?.optional;
         if (optional) continue;
         else throw e;
       }

From 056f2b9d8be9fc62a452166e73b882647b4a8b30 Mon Sep 17 00:00:00 2001
From: DmitryScaletta <dmitryscaletta@mail.ru>
Date: Wed, 15 Nov 2023 17:17:23 +0300
Subject: [PATCH 4/4] Check 'module not found' error by error code

---
 lib/deps.js | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/deps.js b/lib/deps.js
index 94865097..7dfc1203 100644
--- a/lib/deps.js
+++ b/lib/deps.js
@@ -58,13 +58,13 @@ const loadModule = (name) => {
       const sub = appRequire(name + '/' + subName);
       if (lib[subName] && lib[subName] === sub[subName]) continue;
       lib[subName] = sub;
-    } catch (e) {
-      if (e.message.startsWith("Cannot find module '")) {
-        const moduleName = e.message.substring(20, e.message.indexOf("'\n"));
-        const optional = pkg.peerDependenciesMeta?.[moduleName]?.optional;
+    } catch (err) {
+      if (err.code === 'MODULE_NOT_FOUND' && pkg.peerDependenciesMeta) {
+        const moduleName = metautil.between(err.message, "'", "'");
+        const optional = pkg.peerDependenciesMeta[moduleName]?.optional;
         if (optional) continue;
-        else throw e;
       }
+      throw err;
     }
   }
   return lib;