From 37c7a5216f8903629c20cfa4bdfa0203541c12a9 Mon Sep 17 00:00:00 2001
From: Gonzalo Othacehe <gonza.otc@gmail.com>
Date: Thu, 10 Jul 2025 16:53:03 -0300
Subject: [PATCH 01/18] up rules

---
 scripts/solhint-custom/index.js | 64 +++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 22 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 9625027eefe..28d5ebf4fef 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -23,11 +23,11 @@ class Base {
 
 module.exports = [
   class extends Base {
-    static ruleId = 'interface-names';
+    static ruleId = 'interface-only-external-functions';
 
-    ContractDefinition(node) {
-      if (node.kind === 'interface' && !/^I[A-Z]/.test(node.name)) {
-        this.error(node, 'Interface names should have a capital I prefix');
+    FunctionDefinition(node) {
+      if (node.parent.kind === 'interface' && node.visibility !== 'external') {
+        this.error(node, 'Interface functions must be external');
       }
     }
   },
@@ -47,20 +47,36 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-      if (node.isDeclaredConst) {
-        // TODO: expand visibility and fix
-        if (node.visibility === 'private' && /^_/.test(node.name)) {
-          this.error(node, 'Constant variables should not have leading underscore');
+        if (node.isDeclaredConst || node.isImmutable) {
+            if (/^_/.test(node.name)) {
+              this.error(node, 'Constant and immutable variables should not have leading underscore');
+            }
+        }
+        else {
+          if (node.isStateVar) {
+            if (node.visibility === 'private' || node.visibility === 'internal') {
+              if (!/^_/.test(node.name)) {
+                this.error(node, 'Private and internal state variables must have leading underscore');
+              }
+            }
+            else {
+                if (/^_/.test(node.name)) {
+                  this.error(node, 'Public state variables should not have leading underscore');
+                }
+            }
         }
-      } else if (node.visibility === 'private' && !/^_/.test(node.name)) {
-        this.error(node, 'Non-constant private variables must have leading underscore');
       }
     }
 
     FunctionDefinition(node) {
-      if (node.visibility === 'private' || (node.visibility === 'internal' && node.parent.kind !== 'library')) {
+      if (node.visibility === 'private') {
         if (!/^_/.test(node.name)) {
-          this.error(node, 'Private and internal functions must have leading underscore');
+          this.error(node, 'Private functions must have leading underscore');
+        }
+      }
+      if (node.visibility === 'internal' && node.parent.kind !== 'library') {
+        if (!/^_/.test(node.name)) {
+          this.error(node, 'Non-library internal functions must have leading underscore');
         }
       }
       if (node.visibility === 'internal' && node.parent.kind === 'library') {
@@ -68,17 +84,21 @@ module.exports = [
           this.error(node, 'Library internal functions should not have leading underscore');
         }
       }
+      if (node.visibility === 'public' || node.visibility === 'external') {
+        if (/^_/.test(node.name)) {
+          this.error(node, 'Public and external functions should not have leading underscore');
+        }
+      }
     }
   },
 
-  // TODO: re-enable and fix
-  // class extends Base {
-  //   static ruleId = 'no-external-virtual';
-  //
-  //   FunctionDefinition(node) {
-  //     if (node.visibility == 'external' && node.isVirtual) {
-  //       this.error(node, 'Functions should not be external and virtual');
-  //     }
-  //   }
-  // },
+  class extends Base {
+    static ruleId = 'no-external-virtual';
+  
+    FunctionDefinition(node) {
+      if (node.visibility == 'external' && node.isVirtual) {
+        this.error(node, 'Functions should not be external and virtual');
+      }
+    }
+  },
 ];

From 6e13ca783a60367f7d23b93b719a548b96586c41 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 10 Jul 2025 23:38:29 +0200
Subject: [PATCH 02/18] Update index.js

---
 scripts/solhint-custom/index.js | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 28d5ebf4fef..7f6cb5d5b9a 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -47,23 +47,19 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-        if (node.isDeclaredConst || node.isImmutable) {
-            if (/^_/.test(node.name)) {
-              this.error(node, 'Constant and immutable variables should not have leading underscore');
-            }
+      if (node.isDeclaredConst || node.isImmutable) {
+        if (/^_/.test(node.name)) {
+          this.error(node, 'Constant and immutable variables should not have leading underscore');
         }
-        else {
-          if (node.isStateVar) {
-            if (node.visibility === 'private' || node.visibility === 'internal') {
-              if (!/^_/.test(node.name)) {
-                this.error(node, 'Private and internal state variables must have leading underscore');
-              }
-            }
-            else {
-                if (/^_/.test(node.name)) {
-                  this.error(node, 'Public state variables should not have leading underscore');
-                }
-            }
+      } else if (node.isStateVar) {
+        if (node.visibility === 'private' || node.visibility === 'internal') {
+          if (!/^_/.test(node.name)) {
+            this.error(node, 'Private and internal state variables must have leading underscore');
+          }
+        } else {
+          if (/^_/.test(node.name)) {
+            this.error(node, 'Public state variables should not have leading underscore');
+          }
         }
       }
     }

From 56b120f607f79a30afa37091e83edf527f724fe3 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 10 Jul 2025 23:40:26 +0200
Subject: [PATCH 03/18] Update index.js

---
 scripts/solhint-custom/index.js | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 7f6cb5d5b9a..03a33779e8e 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -65,25 +65,17 @@ module.exports = [
     }
 
     FunctionDefinition(node) {
-      if (node.visibility === 'private') {
-        if (!/^_/.test(node.name)) {
-          this.error(node, 'Private functions must have leading underscore');
-        }
+      if (node.visibility === 'private' && !/^_/.test(node.name)) {
+        this.error(node, 'Private functions must have leading underscore');
       }
-      if (node.visibility === 'internal' && node.parent.kind !== 'library') {
-        if (!/^_/.test(node.name)) {
-          this.error(node, 'Non-library internal functions must have leading underscore');
-        }
+      if (node.visibility === 'internal' && node.parent.kind !== 'library' && !/^_/.test(node.name)) {
+        this.error(node, 'Non-library internal functions must have leading underscore');
       }
-      if (node.visibility === 'internal' && node.parent.kind === 'library') {
-        if (/^_/.test(node.name)) {
-          this.error(node, 'Library internal functions should not have leading underscore');
-        }
+      if (node.visibility === 'internal' && node.parent.kind === 'library' && /^_/.test(node.name)) {
+        this.error(node, 'Library internal functions should not have leading underscore');
       }
-      if (node.visibility === 'public' || node.visibility === 'external') {
-        if (/^_/.test(node.name)) {
-          this.error(node, 'Public and external functions should not have leading underscore');
-        }
+      if (node.visibility === 'public' || node.visibility === 'external' && /^_/.test(node.name)) {
+        this.error(node, 'Public and external functions should not have leading underscore');
       }
     }
   },

From ba351f3211ed3d990aa1c822426966c41d13c7bd Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 10 Jul 2025 23:41:44 +0200
Subject: [PATCH 04/18] Update index.js

---
 scripts/solhint-custom/index.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 03a33779e8e..a586790aadd 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -74,8 +74,11 @@ module.exports = [
       if (node.visibility === 'internal' && node.parent.kind === 'library' && /^_/.test(node.name)) {
         this.error(node, 'Library internal functions should not have leading underscore');
       }
-      if (node.visibility === 'public' || node.visibility === 'external' && /^_/.test(node.name)) {
-        this.error(node, 'Public and external functions should not have leading underscore');
+      if (node.visibility === 'public' && /^_/.test(node.name)) {
+        this.error(node, 'Public functions should not have leading underscore');
+      }
+      if (node.visibility === 'external' && /^_/.test(node.name)) {
+        this.error(node, 'External functions should not have leading underscore');
       }
     }
   },

From bee7bc3b497857e2a182b379900c8b396b8d80bc Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 16 Jul 2025 22:31:26 +0200
Subject: [PATCH 05/18] Update index.js

---
 scripts/solhint-custom/index.js | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index a586790aadd..6718ab7b858 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -52,14 +52,14 @@ module.exports = [
           this.error(node, 'Constant and immutable variables should not have leading underscore');
         }
       } else if (node.isStateVar) {
-        if (node.visibility === 'private' || node.visibility === 'internal') {
-          if (!/^_/.test(node.name)) {
-            this.error(node, 'Private and internal state variables must have leading underscore');
-          }
-        } else {
-          if (/^_/.test(node.name)) {
-            this.error(node, 'Public state variables should not have leading underscore');
-          }
+        if (node.visibility === 'private' && !/^_/.test(node.name))
+          this.error(node, 'Private state variables must have leading underscore');
+        }
+        if (node.visibility === 'internal' && !/^_/.test(node.name)) {
+          this.error(node, 'Internal state variables must have leading underscore');
+        }
+        if (node.visibility === 'public' && /^_/.test(node.name)) {
+          this.error(node, 'Public state variables should not have leading underscore');
         }
       }
     }

From f859dd7933f7a1e6fc18ac6c7c129e24ef2497b2 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 16 Jul 2025 22:33:10 +0200
Subject: [PATCH 06/18] Update index.js

---
 scripts/solhint-custom/index.js | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 6718ab7b858..060ee81d6a3 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -47,20 +47,20 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-      if (node.isDeclaredConst || node.isImmutable) {
-        if (/^_/.test(node.name)) {
-          this.error(node, 'Constant and immutable variables should not have leading underscore');
-        }
-      } else if (node.isStateVar) {
-        if (node.visibility === 'private' && !/^_/.test(node.name))
-          this.error(node, 'Private state variables must have leading underscore');
-        }
-        if (node.visibility === 'internal' && !/^_/.test(node.name)) {
-          this.error(node, 'Internal state variables must have leading underscore');
-        }
-        if (node.visibility === 'public' && /^_/.test(node.name)) {
-          this.error(node, 'Public state variables should not have leading underscore');
-        }
+      if (node.isDeclaredConst && /^_/.test(node.name)) {
+        this.error(node, 'Constant variables should not have leading underscore');
+      }
+      if (node.isImmutable && /^_/.test(node.name)) {
+        this.error(node, 'Immutable variables should not have leading underscore');
+      }
+      if (node.isStateVar && node.visibility === 'private' && !/^_/.test(node.name)) {
+        this.error(node, 'Private state variables must have leading underscore');
+      }
+      if (node.isStateVar && node.visibility === 'internal' && !/^_/.test(node.name)) {
+        this.error(node, 'Internal state variables must have leading underscore');
+      }
+      if (node.isStateVar && node.visibility === 'public' && /^_/.test(node.name)) {
+        this.error(node, 'Public state variables should not have leading underscore');
       }
     }
 

From d807d85c14ea35ac533bfc46d5453d65c9ee9d79 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 16 Jul 2025 22:36:28 +0200
Subject: [PATCH 07/18] Update index.js

---
 scripts/solhint-custom/index.js | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 060ee81d6a3..5fe96ee1b3b 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -36,8 +36,7 @@ module.exports = [
     static ruleId = 'private-variables';
 
     VariableDeclaration(node) {
-      const constantOrImmutable = node.isDeclaredConst || node.isImmutable;
-      if (node.isStateVar && !constantOrImmutable && node.visibility !== 'private') {
+      if (node.isStateVar && !node.isDeclaredConst && !node.isImmutable && node.visibility !== 'private') {
         this.error(node, 'State variables must be private');
       }
     }
@@ -47,37 +46,37 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-      if (node.isDeclaredConst && /^_/.test(node.name)) {
+      if (node.isDeclaredConst && node.name.startsWith('_')) {
         this.error(node, 'Constant variables should not have leading underscore');
       }
-      if (node.isImmutable && /^_/.test(node.name)) {
+      if (node.isImmutable && node.name.startsWith('_')) {
         this.error(node, 'Immutable variables should not have leading underscore');
       }
-      if (node.isStateVar && node.visibility === 'private' && !/^_/.test(node.name)) {
+      if (node.isStateVar && node.visibility === 'private' && !node.name.startsWith('_')) {
         this.error(node, 'Private state variables must have leading underscore');
       }
-      if (node.isStateVar && node.visibility === 'internal' && !/^_/.test(node.name)) {
+      if (node.isStateVar && node.visibility === 'internal' && !node.name.startsWith('_')) {
         this.error(node, 'Internal state variables must have leading underscore');
       }
-      if (node.isStateVar && node.visibility === 'public' && /^_/.test(node.name)) {
+      if (node.isStateVar && node.visibility === 'public' && node.name.startsWith('_')) {
         this.error(node, 'Public state variables should not have leading underscore');
       }
     }
 
     FunctionDefinition(node) {
-      if (node.visibility === 'private' && !/^_/.test(node.name)) {
+      if (node.visibility === 'private' && !node.name.startsWith('_')) {
         this.error(node, 'Private functions must have leading underscore');
       }
-      if (node.visibility === 'internal' && node.parent.kind !== 'library' && !/^_/.test(node.name)) {
+      if (node.visibility === 'internal' && node.parent.kind !== 'library' && !node.name.startsWith('_')) {
         this.error(node, 'Non-library internal functions must have leading underscore');
       }
-      if (node.visibility === 'internal' && node.parent.kind === 'library' && /^_/.test(node.name)) {
+      if (node.visibility === 'internal' && node.parent.kind === 'library' && node.name.startsWith('_')) {
         this.error(node, 'Library internal functions should not have leading underscore');
       }
-      if (node.visibility === 'public' && /^_/.test(node.name)) {
+      if (node.visibility === 'public' && node.name.startsWith('_')) {
         this.error(node, 'Public functions should not have leading underscore');
       }
-      if (node.visibility === 'external' && /^_/.test(node.name)) {
+      if (node.visibility === 'external' && node.name.startsWith('_')) {
         this.error(node, 'External functions should not have leading underscore');
       }
     }

From add0ff0fbd91a087855f5ff1d84cf11b21faf6e1 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 17 Jul 2025 21:37:05 +0200
Subject: [PATCH 08/18] fix lint

---
 scripts/solhint-custom/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 5fe96ee1b3b..cfd6dc994a1 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -84,7 +84,7 @@ module.exports = [
 
   class extends Base {
     static ruleId = 'no-external-virtual';
-  
+
     FunctionDefinition(node) {
       if (node.visibility == 'external' && node.isVirtual) {
         this.error(node, 'Functions should not be external and virtual');

From 101f119aa4e6a6c4258c09a9f78653ea41d0e21b Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 24 Jul 2025 16:08:52 +0200
Subject: [PATCH 09/18] improve

---
 scripts/solhint-custom/index.js | 87 +++++++++++++++++++--------------
 1 file changed, 51 insertions(+), 36 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index cfd6dc994a1..39b99be5086 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -14,8 +14,8 @@ class Base {
     }
   }
 
-  error(node, message) {
-    if (!this.ignored) {
+  require(condition, node, message) {
+    if (!condition && !this.ignored) {
       this.reporter.error(node, this.ruleId, message);
     }
   }
@@ -26,8 +26,8 @@ module.exports = [
     static ruleId = 'interface-only-external-functions';
 
     FunctionDefinition(node) {
-      if (node.parent.kind === 'interface' && node.visibility !== 'external') {
-        this.error(node, 'Interface functions must be external');
+      if (node.parent.kind === 'interface') {
+        this.require(node.visibility === 'external', node, 'Interface functions must be external');
       }
     }
   },
@@ -36,8 +36,12 @@ module.exports = [
     static ruleId = 'private-variables';
 
     VariableDeclaration(node) {
-      if (node.isStateVar && !node.isDeclaredConst && !node.isImmutable && node.visibility !== 'private') {
-        this.error(node, 'State variables must be private');
+      if (node.isStateVar) {
+        this.require(
+          node.isDeclaredConst || node.isImmutable || node.visibility === 'private',
+          node,
+          'State variables must be private',
+        );
       }
     }
   },
@@ -46,38 +50,45 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-      if (node.isDeclaredConst && node.name.startsWith('_')) {
-        this.error(node, 'Constant variables should not have leading underscore');
-      }
-      if (node.isImmutable && node.name.startsWith('_')) {
-        this.error(node, 'Immutable variables should not have leading underscore');
-      }
-      if (node.isStateVar && node.visibility === 'private' && !node.name.startsWith('_')) {
-        this.error(node, 'Private state variables must have leading underscore');
-      }
-      if (node.isStateVar && node.visibility === 'internal' && !node.name.startsWith('_')) {
-        this.error(node, 'Internal state variables must have leading underscore');
-      }
-      if (node.isStateVar && node.visibility === 'public' && node.name.startsWith('_')) {
-        this.error(node, 'Public state variables should not have leading underscore');
+      if (node.isDeclaredConst) {
+        this.require(!node.name.startsWith('_'), node, 'Constant variables should not have leading underscore');
+      } else if (node.isImmutable) {
+        this.require(!node.name.startsWith('_'), node, 'Immutable variables should not have leading underscore');
+      } else if (node.isStateVar) {
+        switch (node.visibility) {
+          case 'private':
+            this.require(node.name.startsWith('_'), node, 'Private state variables must have leading underscore');
+            break;
+          case 'internal':
+            this.require(node.name.startsWith('_'), node, 'Internal state variables must have leading underscore');
+            break;
+          case 'public':
+            this.require(!node.name.startsWith('_'), node, 'Public state variables should not have leading underscore');
+            break;
+        }
       }
     }
 
     FunctionDefinition(node) {
-      if (node.visibility === 'private' && !node.name.startsWith('_')) {
-        this.error(node, 'Private functions must have leading underscore');
-      }
-      if (node.visibility === 'internal' && node.parent.kind !== 'library' && !node.name.startsWith('_')) {
-        this.error(node, 'Non-library internal functions must have leading underscore');
-      }
-      if (node.visibility === 'internal' && node.parent.kind === 'library' && node.name.startsWith('_')) {
-        this.error(node, 'Library internal functions should not have leading underscore');
-      }
-      if (node.visibility === 'public' && node.name.startsWith('_')) {
-        this.error(node, 'Public functions should not have leading underscore');
-      }
-      if (node.visibility === 'external' && node.name.startsWith('_')) {
-        this.error(node, 'External functions should not have leading underscore');
+      switch (node.visibility) {
+        case 'external':
+          this.require(!node.name.startsWith('_'), node, 'External functions should not have leading underscore');
+          break;
+        case 'public':
+          this.require(!node.name.startsWith('_'), node, 'Public functions should not have leading underscore');
+          break;
+        case 'internal':
+          this.require(
+            node.name.startsWith('_') !== (node.parent.kind === 'library'),
+            node,
+            node.parent.kind === 'library'
+              ? 'Library internal functions should not have leading underscore'
+              : 'Non-library internal functions must have leading underscore',
+          );
+          break;
+        case 'private':
+          this.require(node.name.startsWith('_'), node, 'Private functions must have leading underscore');
+          break;
       }
     }
   },
@@ -86,8 +97,12 @@ module.exports = [
     static ruleId = 'no-external-virtual';
 
     FunctionDefinition(node) {
-      if (node.visibility == 'external' && node.isVirtual) {
-        this.error(node, 'Functions should not be external and virtual');
+      if (node.visibility == 'external') {
+        this.require(
+          node.isReceiveEther || node.isFallback || !node.isVirtual,
+          node,
+          'Functions should not be external and virtual',
+        );
       }
     }
   },

From ca766d7a161ddabdeaa07eda67d1aa57657d7eab Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 24 Jul 2025 16:18:47 +0200
Subject: [PATCH 10/18] fix code to match new rules

---
 contracts/governance/Governor.sol                         | 2 +-
 contracts/governance/TimelockController.sol               | 8 ++++----
 .../governance/extensions/GovernorTimelockCompound.sol    | 4 ++--
 .../governance/extensions/GovernorTimelockControl.sol     | 2 +-
 .../governance/extensions/GovernorVotesQuorumFraction.sol | 2 +-
 contracts/metatx/ERC2771Forwarder.sol                     | 4 ++--
 contracts/mocks/proxy/UUPSUpgradeableMock.sol             | 2 +-
 contracts/proxy/utils/UUPSUpgradeable.sol                 | 2 +-
 contracts/token/ERC20/extensions/ERC20Permit.sol          | 2 +-
 contracts/utils/Base64.sol                                | 8 ++++----
 contracts/utils/Multicall.sol                             | 2 +-
 scripts/solhint-custom/index.js                           | 7 +++++--
 test/metatx/ERC2771Forwarder.t.sol                        | 2 +-
 13 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 5a7b1617041..c80a82f5b0b 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -653,7 +653,7 @@ abstract contract Governor is Context, ERC165, EIP712, Nonces, IGovernor, IERC72
      * in a governance proposal to recover tokens or Ether that was sent to the governor contract by mistake.
      * Note that if the executor is simply the governor itself, use of `relay` is redundant.
      */
-    function relay(address target, uint256 value, bytes calldata data) external payable virtual onlyGovernance {
+    function relay(address target, uint256 value, bytes calldata data) public payable virtual onlyGovernance {
         (bool success, bytes memory returndata) = target.call{value: value}(data);
         Address.verifyCallResult(success, returndata);
     }
diff --git a/contracts/governance/TimelockController.sol b/contracts/governance/TimelockController.sol
index e608d393d98..93996cc9735 100644
--- a/contracts/governance/TimelockController.sol
+++ b/contracts/governance/TimelockController.sol
@@ -26,7 +26,7 @@ contract TimelockController is AccessControl, ERC721Holder, ERC1155Holder {
     bytes32 public constant PROPOSER_ROLE = keccak256("PROPOSER_ROLE");
     bytes32 public constant EXECUTOR_ROLE = keccak256("EXECUTOR_ROLE");
     bytes32 public constant CANCELLER_ROLE = keccak256("CANCELLER_ROLE");
-    uint256 internal constant _DONE_TIMESTAMP = uint256(1);
+    uint256 internal constant DONE_TIMESTAMP = uint256(1);
 
     mapping(bytes32 id => uint256) private _timestamps;
     uint256 private _minDelay;
@@ -207,7 +207,7 @@ contract TimelockController is AccessControl, ERC721Holder, ERC1155Holder {
         uint256 timestamp = getTimestamp(id);
         if (timestamp == 0) {
             return OperationState.Unset;
-        } else if (timestamp == _DONE_TIMESTAMP) {
+        } else if (timestamp == DONE_TIMESTAMP) {
             return OperationState.Done;
         } else if (timestamp > block.timestamp) {
             return OperationState.Waiting;
@@ -432,7 +432,7 @@ contract TimelockController is AccessControl, ERC721Holder, ERC1155Holder {
         if (!isOperationReady(id)) {
             revert TimelockUnexpectedOperationState(id, _encodeStateBitmap(OperationState.Ready));
         }
-        _timestamps[id] = _DONE_TIMESTAMP;
+        _timestamps[id] = DONE_TIMESTAMP;
     }
 
     /**
@@ -445,7 +445,7 @@ contract TimelockController is AccessControl, ERC721Holder, ERC1155Holder {
      * - the caller must be the timelock itself. This can only be achieved by scheduling and later executing
      * an operation where the timelock is the target and the data is the ABI-encoded call to this function.
      */
-    function updateDelay(uint256 newDelay) external virtual {
+    function updateDelay(uint256 newDelay) public virtual {
         address sender = _msgSender();
         if (sender != address(this)) {
             revert TimelockUnauthorizedCaller(sender);
diff --git a/contracts/governance/extensions/GovernorTimelockCompound.sol b/contracts/governance/extensions/GovernorTimelockCompound.sol
index ea705a76e43..e8572e219b6 100644
--- a/contracts/governance/extensions/GovernorTimelockCompound.sol
+++ b/contracts/governance/extensions/GovernorTimelockCompound.sol
@@ -136,7 +136,7 @@ abstract contract GovernorTimelockCompound is Governor {
     /**
      * @dev Accept admin right over the timelock.
      */
-    // solhint-disable-next-line private-vars-leading-underscore
+    // solhint-disable-next-line openzeppelin/leading-underscore
     function __acceptAdmin() public {
         _timelock.acceptAdmin();
     }
@@ -154,7 +154,7 @@ abstract contract GovernorTimelockCompound is Governor {
 
      * CAUTION: It is not recommended to change the timelock while there are other queued governance proposals.
      */
-    function updateTimelock(ICompoundTimelock newTimelock) external virtual onlyGovernance {
+    function updateTimelock(ICompoundTimelock newTimelock) public virtual onlyGovernance {
         _updateTimelock(newTimelock);
     }
 
diff --git a/contracts/governance/extensions/GovernorTimelockControl.sol b/contracts/governance/extensions/GovernorTimelockControl.sol
index 6aab59c9470..ff963adffaa 100644
--- a/contracts/governance/extensions/GovernorTimelockControl.sol
+++ b/contracts/governance/extensions/GovernorTimelockControl.sol
@@ -146,7 +146,7 @@ abstract contract GovernorTimelockControl is Governor {
      *
      * CAUTION: It is not recommended to change the timelock while there are other queued governance proposals.
      */
-    function updateTimelock(TimelockController newTimelock) external virtual onlyGovernance {
+    function updateTimelock(TimelockController newTimelock) public virtual onlyGovernance {
         _updateTimelock(newTimelock);
     }
 
diff --git a/contracts/governance/extensions/GovernorVotesQuorumFraction.sol b/contracts/governance/extensions/GovernorVotesQuorumFraction.sol
index 5abd7c129b0..c225fe85fa9 100644
--- a/contracts/governance/extensions/GovernorVotesQuorumFraction.sol
+++ b/contracts/governance/extensions/GovernorVotesQuorumFraction.sol
@@ -73,7 +73,7 @@ abstract contract GovernorVotesQuorumFraction is GovernorVotes {
      * - Must be called through a governance proposal.
      * - New numerator must be smaller or equal to the denominator.
      */
-    function updateQuorumNumerator(uint256 newQuorumNumerator) external virtual onlyGovernance {
+    function updateQuorumNumerator(uint256 newQuorumNumerator) public virtual onlyGovernance {
         _updateQuorumNumerator(newQuorumNumerator);
     }
 
diff --git a/contracts/metatx/ERC2771Forwarder.sol b/contracts/metatx/ERC2771Forwarder.sol
index a463e70e019..b1448acf084 100644
--- a/contracts/metatx/ERC2771Forwarder.sol
+++ b/contracts/metatx/ERC2771Forwarder.sol
@@ -61,7 +61,7 @@ contract ERC2771Forwarder is EIP712, Nonces {
         bytes signature;
     }
 
-    bytes32 internal constant _FORWARD_REQUEST_TYPEHASH =
+    bytes32 internal constant FORWARD_REQUEST_TYPEHASH =
         keccak256(
             "ForwardRequest(address from,address to,uint256 value,uint256 gas,uint256 nonce,uint48 deadline,bytes data)"
         );
@@ -222,7 +222,7 @@ contract ERC2771Forwarder is EIP712, Nonces {
         (address recovered, ECDSA.RecoverError err, ) = _hashTypedDataV4(
             keccak256(
                 abi.encode(
-                    _FORWARD_REQUEST_TYPEHASH,
+                    FORWARD_REQUEST_TYPEHASH,
                     request.from,
                     request.to,
                     request.value,
diff --git a/contracts/mocks/proxy/UUPSUpgradeableMock.sol b/contracts/mocks/proxy/UUPSUpgradeableMock.sol
index 8c5641e6ca3..b5e8f506ce4 100644
--- a/contracts/mocks/proxy/UUPSUpgradeableMock.sol
+++ b/contracts/mocks/proxy/UUPSUpgradeableMock.sol
@@ -29,7 +29,7 @@ contract UUPSUpgradeableUnsafeMock is UUPSUpgradeableMock {
 }
 
 contract UUPSUnsupportedProxiableUUID is UUPSUpgradeableMock {
-    function proxiableUUID() external pure override returns (bytes32) {
+    function proxiableUUID() public pure override returns (bytes32) {
         return keccak256("invalid UUID");
     }
 }
diff --git a/contracts/proxy/utils/UUPSUpgradeable.sol b/contracts/proxy/utils/UUPSUpgradeable.sol
index d0f58427f9b..7717637fd1b 100644
--- a/contracts/proxy/utils/UUPSUpgradeable.sol
+++ b/contracts/proxy/utils/UUPSUpgradeable.sol
@@ -69,7 +69,7 @@ abstract contract UUPSUpgradeable is IERC1822Proxiable {
      * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
      * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
      */
-    function proxiableUUID() external view virtual notDelegated returns (bytes32) {
+    function proxiableUUID() public view virtual notDelegated returns (bytes32) {
         return ERC1967Utils.IMPLEMENTATION_SLOT;
     }
 
diff --git a/contracts/token/ERC20/extensions/ERC20Permit.sol b/contracts/token/ERC20/extensions/ERC20Permit.sol
index d593191966a..fc213415112 100644
--- a/contracts/token/ERC20/extensions/ERC20Permit.sol
+++ b/contracts/token/ERC20/extensions/ERC20Permit.sol
@@ -71,7 +71,7 @@ abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712, Nonces {
 
     /// @inheritdoc IERC20Permit
     // solhint-disable-next-line func-name-mixedcase
-    function DOMAIN_SEPARATOR() external view virtual returns (bytes32) {
+    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
         return _domainSeparatorV4();
     }
 }
diff --git a/contracts/utils/Base64.sol b/contracts/utils/Base64.sol
index c6ee6a524aa..4f3e493859e 100644
--- a/contracts/utils/Base64.sol
+++ b/contracts/utils/Base64.sol
@@ -11,14 +11,14 @@ library Base64 {
      * @dev Base64 Encoding/Decoding Table
      * See sections 4 and 5 of https://datatracker.ietf.org/doc/html/rfc4648
      */
-    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-    string internal constant _TABLE_URL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+    string internal constant TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+    string internal constant TABLE_URL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
 
     /**
      * @dev Converts a `bytes` to its Bytes64 `string` representation.
      */
     function encode(bytes memory data) internal pure returns (string memory) {
-        return _encode(data, _TABLE, true);
+        return _encode(data, TABLE, true);
     }
 
     /**
@@ -26,7 +26,7 @@ library Base64 {
      * Output is not padded with `=` as specified in https://www.rfc-editor.org/rfc/rfc4648[rfc4648].
      */
     function encodeURL(bytes memory data) internal pure returns (string memory) {
-        return _encode(data, _TABLE_URL, false);
+        return _encode(data, TABLE_URL, false);
     }
 
     /**
diff --git a/contracts/utils/Multicall.sol b/contracts/utils/Multicall.sol
index 94222feb0f4..c986c3c7cde 100644
--- a/contracts/utils/Multicall.sol
+++ b/contracts/utils/Multicall.sol
@@ -23,7 +23,7 @@ abstract contract Multicall is Context {
      * @dev Receives and executes a batch of function calls on this contract.
      * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
      */
-    function multicall(bytes[] calldata data) external virtual returns (bytes[] memory results) {
+    function multicall(bytes[] calldata data) public virtual returns (bytes[] memory results) {
         bytes memory context = msg.sender == _msgSender()
             ? new bytes(0)
             : msg.data[msg.data.length - _contextSuffixLength():];
diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 39b99be5086..8a86f9aa320 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -50,10 +50,13 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
+      // TODO: do we want that rule ? Should no immutable variable have a prefix regardless of visibility ?
+      //
+      // else if (node.isImmutable) {
+      //   this.require(!node.name.startsWith('_'), node, 'Immutable variables should not have leading underscore');
+      // }
       if (node.isDeclaredConst) {
         this.require(!node.name.startsWith('_'), node, 'Constant variables should not have leading underscore');
-      } else if (node.isImmutable) {
-        this.require(!node.name.startsWith('_'), node, 'Immutable variables should not have leading underscore');
       } else if (node.isStateVar) {
         switch (node.visibility) {
           case 'private':
diff --git a/test/metatx/ERC2771Forwarder.t.sol b/test/metatx/ERC2771Forwarder.t.sol
index 605ae62097e..224367377ff 100644
--- a/test/metatx/ERC2771Forwarder.t.sol
+++ b/test/metatx/ERC2771Forwarder.t.sol
@@ -27,7 +27,7 @@ contract ERC2771ForwarderMock is ERC2771Forwarder {
             _hashTypedDataV4(
                 keccak256(
                     abi.encode(
-                        _FORWARD_REQUEST_TYPEHASH,
+                        FORWARD_REQUEST_TYPEHASH,
                         request.from,
                         request.to,
                         request.value,

From 1525a7b15af7398aa7cd8acc3a8a1cc822747830 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 16:52:50 +0200
Subject: [PATCH 11/18] Remove interface-only-external-functions that is
 already enforced by the compiler

---
 scripts/solhint-custom/index.js | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 8a86f9aa320..3a0e01bfa40 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -22,16 +22,6 @@ class Base {
 }
 
 module.exports = [
-  class extends Base {
-    static ruleId = 'interface-only-external-functions';
-
-    FunctionDefinition(node) {
-      if (node.parent.kind === 'interface') {
-        this.require(node.visibility === 'external', node, 'Interface functions must be external');
-      }
-    }
-  },
-
   class extends Base {
     static ruleId = 'private-variables';
 

From 34e6f7d2c61efe6a8ba878b5b1187ef3afbd9635 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 17:04:42 +0200
Subject: [PATCH 12/18] Update scripts/solhint-custom/index.js

---
 scripts/solhint-custom/index.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 3a0e01bfa40..b18c13b4405 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -90,9 +90,9 @@ module.exports = [
     static ruleId = 'no-external-virtual';
 
     FunctionDefinition(node) {
-      if (node.visibility == 'external') {
+      if (node.visibility == 'external' && node.isVirtual) {
         this.require(
-          node.isReceiveEther || node.isFallback || !node.isVirtual,
+          node.isReceiveEther || node.isFallback,
           node,
           'Functions should not be external and virtual',
         );

From 1c5046b5d0e5253889397ade4cc42e0aac5a53fa Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 17:07:32 +0200
Subject: [PATCH 13/18] js lint

---
 scripts/solhint-custom/index.js | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index b18c13b4405..8191388accc 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -91,11 +91,7 @@ module.exports = [
 
     FunctionDefinition(node) {
       if (node.visibility == 'external' && node.isVirtual) {
-        this.require(
-          node.isReceiveEther || node.isFallback,
-          node,
-          'Functions should not be external and virtual',
-        );
+        this.require(node.isReceiveEther || node.isFallback, node, 'Functions should not be external and virtual');
       }
     }
   },

From 01d53b16c8c8f50eea92eb1ed0e4499c4280291a Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 17:40:12 +0200
Subject: [PATCH 14/18] add no-public-library rule

---
 scripts/solhint-custom/index.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 8191388accc..0306c98ef01 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -95,4 +95,18 @@ module.exports = [
       }
     }
   },
+
+  class extends Base {
+    static ruleId = 'no-public-library';
+
+    FunctionDefinition(node) {
+      if (node.parent.kind === 'library') {
+        this.require(
+          node.visibility === 'internal' || node.visibility === 'private',
+          node,
+          'Library functions should not be internal or private',
+        );
+      }
+    }
+  },
 ];

From 00550a7df76cfd4db17074627152e32fbabf412a Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 17:40:50 +0200
Subject: [PATCH 15/18] update solhint

---
 package-lock.json | 56 +++++++----------------------------------------
 package.json      |  2 +-
 2 files changed, 9 insertions(+), 49 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 8e6df71f0d1..ac6c165a06b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -43,7 +43,7 @@
         "prettier-plugin-solidity": "^2.0.0",
         "rimraf": "^6.0.0",
         "semver": "^7.3.5",
-        "solhint": "^6.0.0",
+        "solhint": "^6.0.1",
         "solhint-plugin-openzeppelin": "file:scripts/solhint-custom",
         "solidity-ast": "^0.4.50",
         "solidity-coverage": "^0.8.14",
@@ -9408,13 +9408,13 @@
       }
     },
     "node_modules/solhint": {
-      "version": "6.0.0",
-      "resolved": "https://registry.npmjs.org/solhint/-/solhint-6.0.0.tgz",
-      "integrity": "sha512-PQGfwFqfeYdebi2tEG1fhVfMjqSzbW3Noz+LYf8UusKe5nkikCghdgEjYQPcGfFZj4snlVyJQt//AaxkubOtVQ==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/solhint/-/solhint-6.0.1.tgz",
+      "integrity": "sha512-Lew5nhmkXqHPybzBzkMzvvWkpOJSSLTkfTZwRriWvfR2naS4YW2PsjVGaoX9tZFmHh7SuS+e2GEGo5FPYYmJ8g==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "@solidity-parser/parser": "^0.20.0",
+        "@solidity-parser/parser": "^0.20.2",
         "ajv": "^6.12.6",
         "ajv-errors": "^1.0.1",
         "antlr4": "^4.13.1-patch-1",
@@ -9424,7 +9424,6 @@
         "commander": "^10.0.0",
         "cosmiconfig": "^8.0.0",
         "fast-diff": "^1.2.0",
-        "fs-extra": "^11.1.0",
         "glob": "^8.0.3",
         "ignore": "^5.2.4",
         "js-yaml": "^4.1.0",
@@ -9432,7 +9431,6 @@
         "lodash": "^4.17.21",
         "pluralize": "^8.0.0",
         "semver": "^7.5.2",
-        "strip-ansi": "^6.0.1",
         "table": "^6.8.1",
         "text-table": "^0.2.0"
       },
@@ -9448,9 +9446,9 @@
       "link": true
     },
     "node_modules/solhint/node_modules/@solidity-parser/parser": {
-      "version": "0.20.1",
-      "resolved": "https://registry.npmjs.org/@solidity-parser/parser/-/parser-0.20.1.tgz",
-      "integrity": "sha512-58I2sRpzaQUN+jJmWbHfbWf9AKfzqCI8JAdFB0vbyY+u8tBRcuTt9LxzasvR0LGQpcRv97eyV7l61FQ3Ib7zVw==",
+      "version": "0.20.2",
+      "resolved": "https://registry.npmjs.org/@solidity-parser/parser/-/parser-0.20.2.tgz",
+      "integrity": "sha512-rbu0bzwNvMcwAjH86hiEAcOeRI2EeK8zCkHDrFykh/Al8mvJeFmjy3UrE7GYQjNwOgbGUUtCn5/k8CB8zIu7QA==",
       "dev": true,
       "license": "MIT"
     },
@@ -9505,21 +9503,6 @@
         "node": ">=14"
       }
     },
-    "node_modules/solhint/node_modules/fs-extra": {
-      "version": "11.3.0",
-      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-11.3.0.tgz",
-      "integrity": "sha512-Z4XaCL6dUDHfP/jT25jJKMmtxvuwbkrD1vNSMFlo9lNLY2c5FHYSQgHPRZUjAB26TpDEoW9HCOgplrdbaPV/ew==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "graceful-fs": "^4.2.0",
-        "jsonfile": "^6.0.1",
-        "universalify": "^2.0.0"
-      },
-      "engines": {
-        "node": ">=14.14"
-      }
-    },
     "node_modules/solhint/node_modules/glob": {
       "version": "8.1.0",
       "resolved": "https://registry.npmjs.org/glob/-/glob-8.1.0.tgz",
@@ -9561,19 +9544,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/solhint/node_modules/jsonfile": {
-      "version": "6.1.0",
-      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-6.1.0.tgz",
-      "integrity": "sha512-5dgndWOriYSm5cnYaJNhalLNDKOqFwyDB/rr1E9ZsGciGvKPs8R2xYGCacuf3z6K1YKDz182fd+fY3cn3pMqXQ==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "universalify": "^2.0.0"
-      },
-      "optionalDependencies": {
-        "graceful-fs": "^4.1.6"
-      }
-    },
     "node_modules/solhint/node_modules/minimatch": {
       "version": "5.1.6",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-5.1.6.tgz",
@@ -9604,16 +9574,6 @@
         "url": "https://github.com/prettier/prettier?sponsor=1"
       }
     },
-    "node_modules/solhint/node_modules/universalify": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/universalify/-/universalify-2.0.1.tgz",
-      "integrity": "sha512-gptHNQghINnc/vTGIk0SOFGFNXw7JVrlRUtConJRlvaw6DuX0wO5Jeko9sWrMBhh+PsYAZ7oXAiOnf/UKogyiw==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">= 10.0.0"
-      }
-    },
     "node_modules/solidity-ast": {
       "version": "0.4.60",
       "resolved": "https://registry.npmjs.org/solidity-ast/-/solidity-ast-0.4.60.tgz",
diff --git a/package.json b/package.json
index f6960972ad5..c01775bd963 100644
--- a/package.json
+++ b/package.json
@@ -86,7 +86,7 @@
     "prettier-plugin-solidity": "^2.0.0",
     "rimraf": "^6.0.0",
     "semver": "^7.3.5",
-    "solhint": "^6.0.0",
+    "solhint": "^6.0.1",
     "solhint-plugin-openzeppelin": "file:scripts/solhint-custom",
     "solidity-ast": "^0.4.50",
     "solidity-coverage": "^0.8.14",

From 728bb002b5d744c28ec7e121f68bb4446508142e Mon Sep 17 00:00:00 2001
From: Arr00 <13561405+arr00@users.noreply.github.com>
Date: Fri, 19 Sep 2025 19:07:59 +0200
Subject: [PATCH 16/18] Update scripts/solhint-custom/index.js

---
 scripts/solhint-custom/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 0306c98ef01..f89052a75cd 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -104,7 +104,7 @@ module.exports = [
         this.require(
           node.visibility === 'internal' || node.visibility === 'private',
           node,
-          'Library functions should not be internal or private',
+          'Library functions should be internal or private',
         );
       }
     }

From 47b57c07c887c9bd75d6a7727baadb50c95f2f11 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Fri, 19 Sep 2025 21:47:20 +0200
Subject: [PATCH 17/18] use solhint commons

---
 scripts/solhint-custom/index.js | 34 +++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/scripts/solhint-custom/index.js b/scripts/solhint-custom/index.js
index 0306c98ef01..7acc20c1eb4 100644
--- a/scripts/solhint-custom/index.js
+++ b/scripts/solhint-custom/index.js
@@ -1,6 +1,9 @@
 const path = require('path');
 const minimatch = require('minimatch');
 
+const { isFallbackFunction } = require('solhint/lib/common/ast-types');
+const { hasLeadingUnderscore } = require('solhint/lib/common/identifier-naming');
+
 // Files matching these patterns will be ignored unless a rule has `static global = true`
 const ignore = ['contracts/mocks/**/*', 'test/**/*'];
 
@@ -40,23 +43,26 @@ module.exports = [
     static ruleId = 'leading-underscore';
 
     VariableDeclaration(node) {
-      // TODO: do we want that rule ? Should no immutable variable have a prefix regardless of visibility ?
-      //
-      // else if (node.isImmutable) {
-      //   this.require(!node.name.startsWith('_'), node, 'Immutable variables should not have leading underscore');
-      // }
       if (node.isDeclaredConst) {
-        this.require(!node.name.startsWith('_'), node, 'Constant variables should not have leading underscore');
+        this.require(!hasLeadingUnderscore(node.name), node, 'Constant variables should not have leading underscore');
       } else if (node.isStateVar) {
         switch (node.visibility) {
           case 'private':
-            this.require(node.name.startsWith('_'), node, 'Private state variables must have leading underscore');
+            this.require(hasLeadingUnderscore(node.name), node, 'Private state variables must have leading underscore');
             break;
           case 'internal':
-            this.require(node.name.startsWith('_'), node, 'Internal state variables must have leading underscore');
+            this.require(
+              hasLeadingUnderscore(node.name),
+              node,
+              'Internal state variables must have leading underscore',
+            );
             break;
           case 'public':
-            this.require(!node.name.startsWith('_'), node, 'Public state variables should not have leading underscore');
+            this.require(
+              !hasLeadingUnderscore(node.name),
+              node,
+              'Public state variables should not have leading underscore',
+            );
             break;
         }
       }
@@ -65,14 +71,14 @@ module.exports = [
     FunctionDefinition(node) {
       switch (node.visibility) {
         case 'external':
-          this.require(!node.name.startsWith('_'), node, 'External functions should not have leading underscore');
+          this.require(!hasLeadingUnderscore(node.name), node, 'External functions should not have leading underscore');
           break;
         case 'public':
-          this.require(!node.name.startsWith('_'), node, 'Public functions should not have leading underscore');
+          this.require(!hasLeadingUnderscore(node.name), node, 'Public functions should not have leading underscore');
           break;
         case 'internal':
           this.require(
-            node.name.startsWith('_') !== (node.parent.kind === 'library'),
+            hasLeadingUnderscore(node.name) !== (node.parent.kind === 'library'),
             node,
             node.parent.kind === 'library'
               ? 'Library internal functions should not have leading underscore'
@@ -80,7 +86,7 @@ module.exports = [
           );
           break;
         case 'private':
-          this.require(node.name.startsWith('_'), node, 'Private functions must have leading underscore');
+          this.require(hasLeadingUnderscore(node.name), node, 'Private functions must have leading underscore');
           break;
       }
     }
@@ -91,7 +97,7 @@ module.exports = [
 
     FunctionDefinition(node) {
       if (node.visibility == 'external' && node.isVirtual) {
-        this.require(node.isReceiveEther || node.isFallback, node, 'Functions should not be external and virtual');
+        this.require(isFallbackFunction(node), node, 'Functions should not be external and virtual');
       }
     }
   },

From eb66607930cb93376ca264ebaa45e06785eab4e1 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Mon, 22 Sep 2025 22:01:52 +0200
Subject: [PATCH 18/18] external non virtual

---
 contracts/mocks/proxy/UUPSUpgradeableMock.sol    | 4 ++--
 contracts/proxy/utils/UUPSUpgradeable.sol        | 2 +-
 contracts/token/ERC20/extensions/ERC20Permit.sol | 2 +-
 test/proxy/utils/UUPSUpgradeable.test.js         | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/contracts/mocks/proxy/UUPSUpgradeableMock.sol b/contracts/mocks/proxy/UUPSUpgradeableMock.sol
index b5e8f506ce4..b44c2be606d 100644
--- a/contracts/mocks/proxy/UUPSUpgradeableMock.sol
+++ b/contracts/mocks/proxy/UUPSUpgradeableMock.sol
@@ -28,8 +28,8 @@ contract UUPSUpgradeableUnsafeMock is UUPSUpgradeableMock {
     }
 }
 
-contract UUPSUnsupportedProxiableUUID is UUPSUpgradeableMock {
-    function proxiableUUID() public pure override returns (bytes32) {
+contract UUPSUnsupportedProxiableUUIDMock is NonUpgradeableMock {
+    function proxiableUUID() external pure returns (bytes32) {
         return keccak256("invalid UUID");
     }
 }
diff --git a/contracts/proxy/utils/UUPSUpgradeable.sol b/contracts/proxy/utils/UUPSUpgradeable.sol
index ce53745ca21..2a88b021156 100644
--- a/contracts/proxy/utils/UUPSUpgradeable.sol
+++ b/contracts/proxy/utils/UUPSUpgradeable.sol
@@ -71,7 +71,7 @@ abstract contract UUPSUpgradeable is IERC1822Proxiable {
      * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
      * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
      */
-    function proxiableUUID() public view virtual notDelegated returns (bytes32) {
+    function proxiableUUID() external view notDelegated returns (bytes32) {
         return ERC1967Utils.IMPLEMENTATION_SLOT;
     }
 
diff --git a/contracts/token/ERC20/extensions/ERC20Permit.sol b/contracts/token/ERC20/extensions/ERC20Permit.sol
index 17e16bdd94e..b89df28be9e 100644
--- a/contracts/token/ERC20/extensions/ERC20Permit.sol
+++ b/contracts/token/ERC20/extensions/ERC20Permit.sol
@@ -71,7 +71,7 @@ abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712, Nonces {
 
     /// @inheritdoc IERC20Permit
     // solhint-disable-next-line func-name-mixedcase
-    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
+    function DOMAIN_SEPARATOR() external view returns (bytes32) {
         return _domainSeparatorV4();
     }
 }
diff --git a/test/proxy/utils/UUPSUpgradeable.test.js b/test/proxy/utils/UUPSUpgradeable.test.js
index 17f86576168..476d1e67663 100644
--- a/test/proxy/utils/UUPSUpgradeable.test.js
+++ b/test/proxy/utils/UUPSUpgradeable.test.js
@@ -9,7 +9,7 @@ async function fixture() {
   const implUpgradeOk = await ethers.deployContract('UUPSUpgradeableMock');
   const implUpgradeUnsafe = await ethers.deployContract('UUPSUpgradeableUnsafeMock');
   const implUpgradeNonUUPS = await ethers.deployContract('NonUpgradeableMock');
-  const implUnsupportedUUID = await ethers.deployContract('UUPSUnsupportedProxiableUUID');
+  const implUnsupportedUUID = await ethers.deployContract('UUPSUnsupportedProxiableUUIDMock');
   // Used for testing non ERC1967 compliant proxies (clones are proxies that don't use the ERC1967 implementation slot)
   const cloneFactory = await ethers.deployContract('$Clones');