Omit missing initializer calls error for initializers named *_unchained

.changeset/strong-guests-push.md

@@ -0,0 +1,5 @@
+---
+'@openzeppelin/upgrades-core': patch
+---
+
+Fix `Missing initializer calls` error when initializer name ends with `_unchained`

packages/core/contracts/test/ValidationsInitializer.sol

@@ -629,6 +629,80 @@ contract Recursive_Ok is Parent {
   }
 }
 
+// ==== Omitting validations of *_unchained for non-parent contracts ====
+
+contract Parent_With_Unchained is Initializable {
+  uint64 x;
+  function __Parent_init() onlyInitializing internal {
+    __Parent_init_unchained();
+  }
+
+  function __Parent_init_unchained() onlyInitializing internal {
+    x = 1;
+  }
+}
+
+contract Child_With_Unchained_Ok is Initializable, Parent_With_Unchained {
+  uint64 y;
+  function __Child_init() onlyInitializing internal {
+    __Parent_init_unchained();
+    __Child_init_unchained();
+  }
+
+  function __Child_init_unchained() onlyInitializing internal {
+    y = 1;
+  }
+}
+
+contract Child_Missing_Parent_Unchained_Call_Bad is Initializable, Parent_With_Unchained {
+  uint64 y;
+  function __Child_init() onlyInitializing internal {
+    // missing call to __Parent_init_unchained
+    __Child_init_unchained();
+  }
+
+  function __Child_init_unchained() onlyInitializing internal {
+    y = 1;
+  }
+}
+
+contract Child_Duplicate_Parent_Unchained_Call_Bad is Initializable, Parent_With_Unchained {
+  uint64 y;
+  function __Child_init() onlyInitializing internal {
+    __Parent_init_unchained();
+    __Parent_init_unchained();
+    __Child_init_unchained();
+  }
+
+  function __Child_init_unchained() onlyInitializing internal {
+    y = 1;
+  }
+}
+
+contract Parent2_With_Unchained is Initializable {
+  uint64 x2;
+  function __Parent2_init() onlyInitializing internal {
+    __Parent2_init_unchained();
+  }
+
+  function __Parent2_init_unchained() onlyInitializing internal {
+    x2 = 1;
+  }
+}
+
+contract Child_Wrong_Order_Parent_Unchained_Call_Warning is Initializable, Parent_With_Unchained, Parent2_With_Unchained {
+  uint64 y;
+  function __Child_init() onlyInitializing internal {
+    __Child_init_unchained();
+    __Parent2_init_unchained();
+    __Parent_init_unchained();
+  }
+
+  function __Child_init_unchained() onlyInitializing internal {
+    y = 1;
+  }
+}
+
 // ==== Complex ERC20 examples ====
 
 contract ERC20_Ok is Initializable, ERC20Upgradeable, ERC20BurnableUpgradeable, ERC20PausableUpgradeable, OwnableUpgradeable, ERC20PermitUpgradeable, ERC20FlashMintUpgradeable, UUPSUpgradeable {

packages/core/src/validate-initializers.test.ts

@@ -237,6 +237,17 @@ testRejects('Recursive_Bad', 'transparent', {
 });
 testAccepts('Recursive_Ok', 'transparent');
 
+testAccepts('Child_With_Unchained_Ok', 'transparent');
+testRejects('Child_Missing_Parent_Unchained_Call_Bad', 'transparent', {
+  contains: ['Missing initializer calls for one or more parent contracts: `Parent_With_Unchained`'],
+  count: 1,
+});
+testRejects('Child_Duplicate_Parent_Unchained_Call_Bad', 'transparent', {
+  contains: ['Duplicate calls found to initializer `__Parent_init_unchained` for contract `Parent_With_Unchained`'],
+  count: 1,
+});
+testAccepts('Child_Wrong_Order_Parent_Unchained_Call_Warning', 'transparent'); // warn 'Expected: Parent_With_Unchained, Parent2_With_Unchained'
+
 testAccepts('ERC20_Ok', 'uups');
 testRejects('ERC20_Bad', 'uups', {
   contains: [

packages/core/src/validate/run/initializer.ts

@@ -264,8 +264,11 @@ function* getInitializerCallExceptions(
     }
   }
 
-  // Report any remaining parents that were not directly initialized
+  // Report any remaining parents that were not directly initialized,
+  // unless this initializer is named `*_unchained` since by design it doesn't need to call parent initializers
+  const unchained = contractInitializer.name.endsWith('_unchained');
   if (
+    !unchained &&
     remainingDirectCalls.length > 0 &&
     !skipCheck('missing-initializer-call', contractDef) &&
     !skipCheck('missing-initializer-call', contractInitializer)