From f0ebcb15f9e720bee5a71cb170123f1a9cb9ec76 Mon Sep 17 00:00:00 2001
From: MichaelMitchell-at <=>
Date: Thu, 15 Aug 2024 05:31:35 -0400
Subject: [PATCH] fix(isolated_declarations): Always emit module declarations
 that perform augmentation

---
 crates/oxc_isolated_declarations/src/lib.rs   |  5 +++++
 .../tests/fixtures/module-declaration.ts      | 21 +++++++++++++++++++
 .../tests/snapshots/module-declaration.snap   | 15 +++++++++++++
 3 files changed, 41 insertions(+)
 create mode 100644 crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
 create mode 100644 crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap

diff --git a/crates/oxc_isolated_declarations/src/lib.rs b/crates/oxc_isolated_declarations/src/lib.rs
index 8485e01d03833b..c1813b03e53bff 100644
--- a/crates/oxc_isolated_declarations/src/lib.rs
+++ b/crates/oxc_isolated_declarations/src/lib.rs
@@ -314,6 +314,11 @@ impl<'a> IsolatedDeclarations<'a> {
                         new_ast_stmts.push(Statement::ImportDeclaration(decl));
                     }
                 }
+                Statement::TSModuleDeclaration(decl) => {
+                    if decl.kind.is_global() || decl.id.is_string_literal() {
+                        new_ast_stmts.push(Statement::TSModuleDeclaration(decl));
+                    }
+                }
                 _ => {}
             }
         }
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts b/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
new file mode 100644
index 00000000000000..f88da9d55f95c1
--- /dev/null
+++ b/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
@@ -0,0 +1,21 @@
+import 'foo';
+declare module 'foo' {
+    interface Foo {}
+    const foo = 42;
+}
+
+declare global {
+    interface Bar {}
+    const bar = 42 ;
+}
+
+// should not be emitted
+module baz {
+    interface Baz {}
+    const baz = 42;
+}
+
+declare module x {
+    interface Qux {}
+    const qux = 42;
+}
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap b/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap
new file mode 100644
index 00000000000000..2c3ddd956960fb
--- /dev/null
+++ b/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap
@@ -0,0 +1,15 @@
+---
+source: crates/oxc_isolated_declarations/tests/mod.rs
+input_file: crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
+---
+==================== .D.TS ====================
+
+import "foo";
+declare module "foo" {
+	interface Foo {}
+	const foo = 42;
+}
+declare global {
+	interface Bar {}
+	const bar = 42;
+}