Default values supporting scalar and object

.chronus/changes/almend-DefaultValueScalarObject-2024-8-16-12-2-59.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-autorest"
+---
+
+Added support to use Scalar and Object as default types

packages/typespec-autorest/src/lib.ts

@@ -285,12 +285,6 @@ export const $lib = createTypeSpecLibrary({
           "Empty unions are not supported for OpenAPI v2 - enums must have at least one value.",
       },
     },
-    "invalid-default": {
-      severity: "error",
-      messages: {
-        default: paramMessage`Invalid type '${"type"}' for a default value`,
-      },
-    },
     "invalid-multi-collection-format": {
       severity: "error",
       messages: {

packages/typespec-autorest/src/openapi.ts

@@ -91,6 +91,7 @@ import {
   reportDeprecated,
   resolveEncodedName,
   resolvePath,
+  serializeValueAsJson,
 } from "@typespec/compiler";
 import { TwoLevelMap } from "@typespec/compiler/utils";
 import {
@@ -1316,7 +1317,7 @@ export async function getOpenAPIForService(
       in: "formData",
       ...base,
       ...(getFormDataSchema(param.type, schemaContext, base.name) as any),
-      default: param.defaultValue && getDefaultValue(param.defaultValue),
+      default: param.defaultValue && getDefaultValue(param.defaultValue, param),
     };
 
     Object.assign(
@@ -1376,7 +1377,7 @@ export async function getOpenAPIForService(
         collectionFormat === "csv" && schema.items === undefined // If csv
           ? undefined
           : (collectionFormat as any),
-      default: param.param.defaultValue && getDefaultValue(param.param.defaultValue),
+      default: param.param.defaultValue && getDefaultValue(param.param.defaultValue, param.param),
       ...base,
       ...schema,
     };
@@ -1390,7 +1391,7 @@ export async function getOpenAPIForService(
 
     const result: OpenAPI2PathParameter = {
       in: "path",
-      default: param.param.defaultValue && getDefaultValue(param.param.defaultValue),
+      default: param.param.defaultValue && getDefaultValue(param.param.defaultValue, param.param),
       ...base,
       ...getSimpleParameterSchema(param.param, schemaContext, base.name),
     };
@@ -1415,7 +1416,7 @@ export async function getOpenAPIForService(
     }
     return {
       in: "header",
-      default: param.defaultValue && getDefaultValue(param.defaultValue),
+      default: param.defaultValue && getDefaultValue(param.defaultValue, param),
       ...base,
       collectionFormat: collectionFormat as any,
       ...getSimpleParameterSchema(param, schemaContext, base.name),
@@ -1801,27 +1802,8 @@ export async function getOpenAPIForService(
     return getSchemaForType(variant.type, schemaContext)!;
   }
 
-  function getDefaultValue(defaultType: Value): any {
-    switch (defaultType.valueKind) {
-      case "StringValue":
-        return defaultType.value;
-      case "NumericValue":
-        return defaultType.value.asNumber() ?? undefined;
-      case "BooleanValue":
-        return defaultType.value;
-      case "ArrayValue":
-        return defaultType.values.map((x) => getDefaultValue(x));
-      case "NullValue":
-        return null;
-      case "EnumValue":
-        return defaultType.value.value ?? defaultType.value.name;
-      default:
-        reportDiagnostic(program, {
-          code: "invalid-default",
-          format: { type: defaultType.valueKind },
-          target: defaultType,
-        });
-    }
+  function getDefaultValue(defaultType: Value, modelProperty: ModelProperty): any {
+    return serializeValueAsJson(program, defaultType, modelProperty);
   }
 
   function includeDerivedModel(model: Model): boolean {
@@ -1960,7 +1942,7 @@ export async function getOpenAPIForService(
       applySummary(prop, property);
 
       if (prop.defaultValue && !("$ref" in property)) {
-        property.default = getDefaultValue(prop.defaultValue);
+        property.default = getDefaultValue(prop.defaultValue, prop);
       }
 
       if (isReadonlyProperty(program, prop)) {

packages/typespec-autorest/test/models.test.ts

@@ -912,4 +912,27 @@ describe("typespec-autorest: model definitions", () => {
       });
     });
   });
+
+  it("encode know scalar as a default value", async () => {
+    const res = await oapiForModel(
+      "Test",
+      `
+        model Test { @encode("rfc7231") minDate: utcDateTime = utcDateTime.fromISO("2024-01-01T11:32:00Z"); }
+      `,
+    );
+
+    expect(res.defs.Test.properties.minDate.default).toEqual("Mon, 01 Jan 2024 11:32:00 GMT");
+  });
+
+  it("object value used as a default value", async () => {
+    const res = await oapiForModel(
+      "Test",
+      `
+        model Test { Pet: {name: string;  @encode("rfc7231")birthday: utcDateTime} = #{ name: "Dog", birthday:utcDateTime.fromISO("2024-01-01T11:32:00Z")}}
+      `,
+    );
+
+    expect(res.defs.Test.properties.Pet.default.name).toEqual("Dog");
+    expect(res.defs.Test.properties.Pet.default.birthday).toEqual("Mon, 01 Jan 2024 11:32:00 GMT");
+  });
 });