From f58485edfc4e64347aeb2b828ab82e2f92e9580a Mon Sep 17 00:00:00 2001
From: Mark Probst <mark.probst@gmail.com>
Date: Mon, 20 Jul 2026 18:00:18 -0400
Subject: [PATCH] fix(core): preserve JSON Schema enum case order (#1289)

ConvenienceRenderer.forEachEnumCase always alphabetized enum cases by
their rendered name before handing them to every language renderer's
emitEnum, so C++ (and other languages) generated enums in alphabetical
order instead of the order declared in the source JSON Schema/JSON.
Stop sorting and let the existing insertion order (already preserved
by the underlying case-names map) flow through unchanged.

Co-Authored-By: gpt-5.6-sol via pi <noreply@openai.com>
---
 .../quicktype-core/src/ConvenienceRenderer.ts |  5 +--
 test/unit/enum-order.test.ts                  | 32 +++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 test/unit/enum-order.test.ts

diff --git a/packages/quicktype-core/src/ConvenienceRenderer.ts b/packages/quicktype-core/src/ConvenienceRenderer.ts
index de5901e6e2..af8ff16031 100644
--- a/packages/quicktype-core/src/ConvenienceRenderer.ts
+++ b/packages/quicktype-core/src/ConvenienceRenderer.ts
@@ -995,10 +995,7 @@ export abstract class ConvenienceRenderer extends Renderer {
         f: (name: Name, jsonName: string, position: ForEachPosition) => void,
     ): void {
         const caseNames = defined(this._caseNamesStoreView).get(e);
-        const sortedCaseNames = mapSortBy(caseNames, (n) =>
-            defined(this.names.get(n)),
-        );
-        this.forEachWithBlankLines(sortedCaseNames, blankLocations, f);
+        this.forEachWithBlankLines(caseNames, blankLocations, f);
     }
 
     protected forEachTransformation(
diff --git a/test/unit/enum-order.test.ts b/test/unit/enum-order.test.ts
new file mode 100644
index 0000000000..da930ac15c
--- /dev/null
+++ b/test/unit/enum-order.test.ts
@@ -0,0 +1,32 @@
+import {
+    InputData,
+    JSONSchemaInput,
+    quicktype,
+} from "../../packages/quicktype-core/src/index.js";
+import { expect, test } from "vitest";
+
+const schema = JSON.stringify({
+    $schema: "http://json-schema.org/draft-04/schema#",
+    title: "Test",
+    type: "object",
+    properties: {
+        errorCode: {
+            type: "string",
+            enum: ["B", "A", "E"],
+        },
+    },
+});
+
+test("preserves JSON Schema enum case order", async () => {
+    const schemaInput = new JSONSchemaInput(undefined);
+    await schemaInput.addSource({ name: "Test", schema });
+
+    const inputData = new InputData();
+    inputData.addInput(schemaInput);
+
+    const result = await quicktype({ inputData, lang: "c++" });
+
+    expect(result.lines).toContain(
+        "    enum class ErrorCode : int { B, A, E };",
+    );
+});