Fix invalid enum output when x-enum-descriptions contains a line break

.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).

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 */

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
 }`);
   });
 });