From b0bdc45966b8846a4103a5624fc37f427aa42339 Mon Sep 17 00:00:00 2001
From: lonyele <skyrabbits1@gmail.com>
Date: Sat, 12 Feb 2022 21:00:03 +0900
Subject: [PATCH 1/2] feat: find if ancestor namespace is declared

---
 .../src/rules/init-declarations.ts            | 25 +++++++++++++++----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/init-declarations.ts b/packages/eslint-plugin/src/rules/init-declarations.ts
index 611687b0e9f..a10035c0691 100644
--- a/packages/eslint-plugin/src/rules/init-declarations.ts
+++ b/packages/eslint-plugin/src/rules/init-declarations.ts
@@ -35,11 +35,7 @@ export default createRule<Options, MessageIds>({
           if (node.declare) {
             return;
           }
-          if (
-            node.parent?.type === AST_NODE_TYPES.TSModuleBlock &&
-            node.parent.parent?.type === AST_NODE_TYPES.TSModuleDeclaration &&
-            node.parent.parent?.declare
-          ) {
+          if (isAncestorNamespaceDeclared(node)) {
             return;
           }
         }
@@ -47,5 +43,24 @@ export default createRule<Options, MessageIds>({
         rules['VariableDeclaration:exit'](node);
       },
     };
+
+    function isAncestorNamespaceDeclared(
+      node: TSESTree.VariableDeclaration,
+    ): boolean {
+      let ancestor = node.parent;
+
+      while (ancestor) {
+        if (
+          ancestor.type === AST_NODE_TYPES.TSModuleDeclaration &&
+          ancestor.declare
+        ) {
+          return true;
+        }
+
+        ancestor = ancestor.parent;
+      }
+
+      return false;
+    }
   },
 });

From 7c2b112f0f527dc37f5d315cf2cbb54a670851e0 Mon Sep 17 00:00:00 2001
From: lonyele <skyrabbits1@gmail.com>
Date: Sat, 12 Feb 2022 21:00:28 +0900
Subject: [PATCH 2/2] test: add nested namespace cases

---
 .../tests/rules/init-declarations.test.ts     | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/packages/eslint-plugin/tests/rules/init-declarations.test.ts b/packages/eslint-plugin/tests/rules/init-declarations.test.ts
index 95d9a08799a..29e9025f734 100644
--- a/packages/eslint-plugin/tests/rules/init-declarations.test.ts
+++ b/packages/eslint-plugin/tests/rules/init-declarations.test.ts
@@ -341,6 +341,35 @@ namespace myLib {
       `,
       options: ['always'],
     },
+    {
+      code: `
+declare namespace myLib1 {
+  const foo: number;
+  namespace myLib2 {
+    let bar: string;
+    namespace myLib3 {
+      let baz: object;
+    }
+  }
+}
+      `,
+      options: ['always'],
+    },
+
+    {
+      code: `
+declare namespace myLib1 {
+  const foo: number;
+  namespace myLib2 {
+    let bar: string;
+    namespace myLib3 {
+      let baz: object;
+    }
+  }
+}
+      `,
+      options: ['never'],
+    },
   ],
   invalid: [
     // checking compatibility with base rule
@@ -724,5 +753,36 @@ namespace myLib {
         },
       ],
     },
+    {
+      code: `
+namespace myLib1 {
+  const foo: number;
+  namespace myLib2 {
+    let bar: string;
+    namespace myLib3 {
+      let baz: object;
+    }
+  }
+}
+      `,
+      options: ['always'],
+      errors: [
+        {
+          messageId: 'initialized',
+          data: { idName: 'foo' },
+          type: AST_NODE_TYPES.VariableDeclarator,
+        },
+        {
+          messageId: 'initialized',
+          data: { idName: 'bar' },
+          type: AST_NODE_TYPES.VariableDeclarator,
+        },
+        {
+          messageId: 'initialized',
+          data: { idName: 'baz' },
+          type: AST_NODE_TYPES.VariableDeclarator,
+        },
+      ],
+    },
   ],
 });