From 60f988a8fd1cf44fc04f3f42ea1f8060688ac28a Mon Sep 17 00:00:00 2001
From: greymoth-jp <246701683+greymoth-jp@users.noreply.github.com>
Date: Mon, 29 Jun 2026 21:24:45 +0900
Subject: [PATCH] fix: collapse line breaks in x-enum-descriptions so generated
 enums stay valid

---
 .changeset/enum-description-line-break.md       |  5 +++++
 packages/openapi-typescript/src/lib/ts.ts       |  7 ++++++-
 packages/openapi-typescript/test/lib/ts.test.ts | 17 +++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/enum-description-line-break.md

diff --git a/.changeset/enum-description-line-break.md b/.changeset/enum-description-line-break.md
new file mode 100644
index 000000000..6a7d0199e
--- /dev/null
+++ b/.changeset/enum-description-line-break.md
@@ -0,0 +1,5 @@
+---
+"openapi-typescript": patch
+---
+
+Keep multi-line `x-enum-descriptions` on a single comment line. A description containing a line break previously ended the `//` comment early and pushed the remaining text onto its own line as code, producing an invalid `enum` (only relevant with the `enum` option).
diff --git a/packages/openapi-typescript/src/lib/ts.ts b/packages/openapi-typescript/src/lib/ts.ts
index d1f41eb88..c3fef9d9f 100644
--- a/packages/openapi-typescript/src/lib/ts.ts
+++ b/packages/openapi-typescript/src/lib/ts.ts
@@ -446,7 +446,12 @@ export function tsEnumMember(value: string | number, metadata: { name?: string;
     return member;
   }
 
-  return ts.addSyntheticLeadingComment(member, ts.SyntaxKind.SingleLineCommentTrivia, ` ${trimmedDescription}`, true);
+  return ts.addSyntheticLeadingComment(
+    member,
+    ts.SyntaxKind.SingleLineCommentTrivia,
+    ` ${trimmedDescription.replace(LB_RE, " ")}`,
+    true,
+  );
 }
 
 /** Create an intersection type */
diff --git a/packages/openapi-typescript/test/lib/ts.test.ts b/packages/openapi-typescript/test/lib/ts.test.ts
index 79e5b4571..4e6731d30 100644
--- a/packages/openapi-typescript/test/lib/ts.test.ts
+++ b/packages/openapi-typescript/test/lib/ts.test.ts
@@ -324,6 +324,23 @@ describe("tsEnum", () => {
     Etc_GMTPlus0 = "Etc/GMT+0",
     Etc_GMTPlus1 = "Etc/GMT+1",
     Etc_GMT_1 = "Etc/GMT-1"
+}`);
+  });
+
+  test("multi-line x-enum-descriptions stay on a single comment line", () => {
+    expect(
+      astToString(
+        tsEnum(
+          ".Error.code.",
+          [100, 101],
+          [{ description: "Code 100\nspanning two lines" }, { description: "Code 101" }],
+        ),
+      ).trim(),
+    ).toBe(`enum ErrorCode {
+    // Code 100 spanning two lines
+    Value100 = 100,
+    // Code 101
+    Value101 = 101
 }`);
   });
 });