Fix immutable arrays (#1643)

Author: drwpow

packages/openapi-fetch/package.json

@@ -74,6 +74,6 @@
     "openapi-typescript-fetch": "^1.1.3",
     "superagent": "^9.0.0",
     "typescript": "^5.4.5",
-    "vitest": "^1.5.0"
+    "vitest": "^1.5.2"
   }
 }

packages/openapi-typescript/examples/github-api-export-type-immutable.ts

@@ -60,7 +60,7 @@
     "typescript": "^5.x"
   },
   "dependencies": {
-    "@redocly/openapi-core": "^1.11.0",
+    "@redocly/openapi-core": "^1.12.0",
     "ansi-colors": "^4.1.3",
     "supports-color": "^9.4.0",
     "yargs-parser": "^21.1.1"
@@ -74,7 +74,7 @@
     "esbuild": "^0.20.2",
     "execa": "^7.2.0",
     "typescript": "^5.4.5",
-    "vite-node": "^1.5.0",
-    "vitest": "^1.5.0"
+    "vite-node": "^1.5.2",
+    "vitest": "^1.5.2"
   }
 }

packages/openapi-typescript/examples/github-api-immutable.ts

@@ -323,9 +323,14 @@ function transformSchemaObjectCore(schemaObject: SchemaObject, options: Transfor
         }
       }
 
-      return ts.isTupleTypeNode(itemType) || ts.isArrayTypeNode(itemType)
-        ? itemType
-        : ts.factory.createArrayTypeNode(itemType); // wrap itemType in array type, but only if not a tuple or array already
+      const finalType =
+        ts.isTupleTypeNode(itemType) || ts.isArrayTypeNode(itemType)
+          ? itemType
+          : ts.factory.createArrayTypeNode(itemType); // wrap itemType in array type, but only if not a tuple or array already
+
+      return options.ctx.immutable
+        ? ts.factory.createTypeOperatorNode(ts.SyntaxKind.ReadonlyKeyword, finalType)
+        : finalType;
     }
 
     // polymorphic, or 3.1 nullable

packages/openapi-typescript/package.json

@@ -151,9 +151,28 @@ describe("transformSchemaObject > array", () => {
       {
         given: {
           type: "array",
-          items: { type: "array", items: { type: "string" } },
+          items: { type: "string" },
         },
-        want: "string[][]",
+        want: "readonly string[]",
+        options: {
+          ...DEFAULT_OPTIONS,
+          ctx: { ...DEFAULT_OPTIONS.ctx, immutable: true },
+        },
+      },
+    ],
+    [
+      "options > immutable: true (tuple)",
+      {
+        given: {
+          type: "array",
+          items: { type: "number" },
+          prefixItems: [{ type: "number" }, { type: "number" }, { type: "number" }],
+        },
+        want: `readonly [
+    number,
+    number,
+    number
+]`,
         options: {
           ...DEFAULT_OPTIONS,
           ctx: { ...DEFAULT_OPTIONS.ctx, immutable: true },

packages/openapi-typescript/src/transform/schema-object.ts

@@ -308,7 +308,7 @@ describe("transformSchemaObject > object", () => {
           },
         },
         want: `{
-    readonly array?: {
+    readonly array?: readonly {
         readonly [key: string]: unknown;
     }[] | null;
 }`,