From ca0585eb23c62367c81f308b5d5efcd7bb2a571c Mon Sep 17 00:00:00 2001
From: Hasegawa-Yukihiro <y.h.baskeeee@icloud.com>
Date: Thu, 9 Apr 2026 21:49:50 +0900
Subject: [PATCH] fix: update ReadonlyArray type detection to use readonly
 modifier

---
 packages/openapi-typescript/src/lib/ts.ts         |  2 +-
 packages/openapi-typescript/test/node-api.test.ts | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/openapi-typescript/src/lib/ts.ts b/packages/openapi-typescript/src/lib/ts.ts
index d1f41eb88..9ffce3b5e 100644
--- a/packages/openapi-typescript/src/lib/ts.ts
+++ b/packages/openapi-typescript/src/lib/ts.ts
@@ -608,7 +608,7 @@ export function tsReadonlyArray(type: ts.TypeNode, injectFooter?: ts.Node[]): ts
     !injectFooter.some((node) => ts.isTypeAliasDeclaration(node) && node?.name?.escapedText === "ReadonlyArray")
   ) {
     const helper = stringToAST(
-      "type ReadonlyArray<T> = [Exclude<T, undefined>] extends [unknown[]] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;",
+      "type ReadonlyArray<T> = [Exclude<T, undefined>] extends [readonly unknown[]] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;",
     )[0] as any;
     injectFooter.push(helper);
   }
diff --git a/packages/openapi-typescript/test/node-api.test.ts b/packages/openapi-typescript/test/node-api.test.ts
index b22f8ad18..d28b88a71 100644
--- a/packages/openapi-typescript/test/node-api.test.ts
+++ b/packages/openapi-typescript/test/node-api.test.ts
@@ -996,7 +996,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const pathsUrlGetParametersQueryStatusValues: ReadonlyArray<FlattenedDeepRequired<paths>["/url"]["get"]["parameters"]["query"]["status"]> = ["active", "inactive"];
 export const statusValues: ReadonlyArray<FlattenedDeepRequired<components>["schemas"]["Status"]> = ["active", "inactive"];
@@ -1051,7 +1051,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const complexEditKeyDtoStatesValues: ReadonlyArray<FlattenedDeepRequired<components>["schemas"]["ComplexEditKeyDto"]["states"][string]> = ["TRANSLATED", "REVIEWED"];
 export type operations = Record<string, never>;`,
@@ -1230,7 +1230,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const pathsAnalyticsDataGetResponses400ContentApplicationJsonAnyOf0MessageValues: ReadonlyArray<Extract<FlattenedDeepRequired<paths>["/analytics/data"]["get"]["responses"]["400"]["content"]["application/json"], {
     message: unknown;
@@ -1462,7 +1462,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const pathsTestGetRequestBodyContentApplicationJsonStatusValues: ReadonlyArray<FlattenedDeepRequired<paths>["/test"]["get"]["requestBody"]["content"]["application/json"]["status"]> = ["active", "inactive"];
 export type operations = Record<string, never>;`,
@@ -1557,7 +1557,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const resourceItemsOneOf0TypeValues: ReadonlyArray<Extract<FlattenedDeepRequired<components>["schemas"]["Resource"]["items"], {
     type: unknown;
@@ -1658,7 +1658,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const resourceItemsOneOf0NestedTypeValues: ReadonlyArray<Extract<Extract<FlattenedDeepRequired<components>["schemas"]["Resource"]["items"], {
     nested: unknown;
@@ -1774,7 +1774,7 @@ type FlattenedDeepRequired<T> = {
 type ReadonlyArray<T> = [
     Exclude<T, undefined>
 ] extends [
-    unknown[]
+    readonly unknown[]
 ] ? Readonly<Exclude<T, undefined>> : Readonly<Exclude<T, undefined>[]>;
 export const resourceOuterOneOf0KindValues: ReadonlyArray<Extract<FlattenedDeepRequired<components>["schemas"]["Resource"]["outer"], {
     kind: unknown;