Merge branch 'python-sample-test-generation-optimization' of https://github.com/microsoft/typespec into python-sample-test-generation-optimization

Author: msyyc

.chronus/changes/fix-unknown-scalar-constructors-2026-0-27-17-36-5-2.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+  - "@typespec/openapi3"
+---
+
+Handle use of `.now()` constructor on date time types in examples and default.

.chronus/changes/fix-unknown-scalar-constructors-2026-0-27-17-36-5.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: feature
+packages:
+  - "@typespec/compiler"
+---
+
+[API] `serializeValueAsJson` throws a `UnsupportedScalarConstructorError` for unsupported scalar constructor instead of crashing

.chronus/changes/python-enumMemberTypesMap-2026-0-29-16-11-6.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/http-client-python"
+---
+
+Properly cache enum values

eng/common/config/area.ts

@@ -55,6 +55,7 @@ export const CIRules = {
     "!.prettierrc.json",
     "!cspell.yaml", // CSpell is already run as its dedicated CI(via github action)
     "!eslint.config.json", // Eslint is already run as its dedicated CI(via github action)
+    "!.chronus/**/*", // Used across emitters
     ...ignore(isolatedEmitters),
     ...ignore(AreaPaths["emitter:client:csharp"]),
     ...ignore(AreaPaths["emitter:client:java"]),

website/src/components/editor-tabs.astro …o-utils/src/components/editor-tabs.astrowebsite/src/components/editor-tabs.astro renamed to packages/astro-utils/src/components/editor-tabs.astro website/src/components/editor-tabs.astro renamed to packages/astro-utils/src/components/editor-tabs.astro

@@ -43,6 +43,12 @@ export default function (playgroundUrl: string) {
         display: flex;
         align-items: center;
         padding: 0 0.5rem;
+        text-decoration: none;
+        color: var(--colorPaletteGreenBackground3);
+
+        &:hover {
+          color: var(--colorPaletteGreenBackground4);
+        }
       }
 
       .tryit-link.with-title {
@@ -59,12 +65,7 @@ export default function (playgroundUrl: string) {
         right: 0px;
         height: 34px;
       }
-        
 
-      .tryit-link {
-        text-decoration: none;
-        color: var(--colorPaletteGreenBackground3);
-      }
 
       .play {
         height: 20px;
@@ -85,7 +86,7 @@ export default function (playgroundUrl: string) {
 
         const compilerOptions = JSON.parse(tryitStr);
         const extraElements = [];
-        const hasTitle = metaOptions.getString("title");
+        const hasTitle = codeBlock.props.title || metaOptions.getString("title");
         extraElements.push(
           h(
             "a",

packages/astro-utils/src/expressive-code/plugins/tsp-tryit-code.ts

@@ -4,6 +4,7 @@
     "allowImportingTsExtensions": false,
     "noEmit": false,
     "declaration": true,
+    "sourceMap": true,
     "rootDir": "src",
     "outDir": "dist"
   },

packages/astro-utils/tsconfig.build.json

@@ -12,6 +12,38 @@ import {
 } from "../core/types.js";
 import { getEncode, resolveEncodedName, type EncodeData } from "./decorators.js";
 
+/**
+ * Error thrown when a scalar value cannot be serialized because it uses an unsupported constructor.
+ */
+export class UnsupportedScalarConstructorError extends Error {
+  constructor(
+    public readonly scalarName: string,
+    public readonly constructorName: string,
+    public readonly supportedConstructors: readonly string[],
+  ) {
+    super(
+      `Cannot serialize scalar '${scalarName}' with constructor '${constructorName}'. Supported constructors: ${supportedConstructors.join(", ")}`,
+    );
+    this.name = "UnsupportedScalarConstructorError";
+  }
+}
+
+export interface ValueJsonSerializers {
+  /** Custom handler to serialize a scalar value
+   * @param value The scalar value to serialize
+   * @param type The type of the scalar value in the current context
+   * @param encodeAs The encoding information for the scalar value, if any
+   * @param originalFn The original serialization function to fall back to. Throws `UnsupportedScalarConstructorError` if the scalar constructor is not supported.
+   * @returns The serialized value
+   */
+  serializeScalarValue?: (
+    value: ScalarValue,
+    type: Type,
+    encodeAs: EncodeData | undefined,
+    originalFn: (value: ScalarValue, type: Type, encodeAs: EncodeData | undefined) => unknown,
+  ) => unknown;
+}
+
 /**
  * Serialize the given TypeSpec value as a JSON object using the given type and its encoding annotations.
  * The Value MUST be assignable to the given type.
@@ -21,9 +53,16 @@ export function serializeValueAsJson(
   value: Value,
   type: Type,
   encodeAs?: EncodeData,
+  handlers?: ValueJsonSerializers,
 ): unknown {
   if (type.kind === "ModelProperty") {
-    return serializeValueAsJson(program, value, type.type, encodeAs ?? getEncode(program, type));
+    return serializeValueAsJson(
+      program,
+      value,
+      type.type,
+      encodeAs ?? getEncode(program, type),
+      handlers,
+    );
   }
   switch (value.valueKind) {
     case "NullValue":
@@ -48,7 +87,7 @@ export function serializeValueAsJson(
     case "ObjectValue":
       return serializeObjectValueAsJson(program, value, type);
     case "ScalarValue":
-      return serializeScalarValueAsJson(program, value, type, encodeAs);
+      return serializeScalarValueAsJson(program, value, type, encodeAs, handlers);
   }
 }
 
@@ -149,7 +188,17 @@ function serializeScalarValueAsJson(
   value: ScalarValue,
   type: Type,
   encodeAs: EncodeData | undefined,
+  handlers?: ValueJsonSerializers,
 ): unknown {
+  if (handlers?.serializeScalarValue) {
+    return handlers.serializeScalarValue(
+      value,
+      type,
+      encodeAs,
+      serializeScalarValueAsJson.bind(null, program, value, type, encodeAs, undefined),
+    );
+  }
+
   const result = resolveKnownScalar(program, value.scalar);
   if (result === undefined) {
     return serializeValueAsJson(program, value.value.args[0], value.value.args[0].type);
@@ -159,15 +208,30 @@ function serializeScalarValueAsJson(
 
   switch (result.scalar.name) {
     case "utcDateTime":
-      return ScalarSerializers.utcDateTime((value.value.args[0] as any as any).value, encodeAs);
+      if (value.value.name === "fromISO") {
+        return ScalarSerializers.utcDateTime((value.value.args[0] as any).value, encodeAs);
+      }
+      throw new UnsupportedScalarConstructorError("utcDateTime", value.value.name, ["fromISO"]);
     case "offsetDateTime":
-      return ScalarSerializers.offsetDateTime((value.value.args[0] as any).value, encodeAs);
+      if (value.value.name === "fromISO") {
+        return ScalarSerializers.offsetDateTime((value.value.args[0] as any).value, encodeAs);
+      }
+      throw new UnsupportedScalarConstructorError("offsetDateTime", value.value.name, ["fromISO"]);
     case "plainDate":
-      return ScalarSerializers.plainDate((value.value.args[0] as any).value);
+      if (value.value.name === "fromISO") {
+        return ScalarSerializers.plainDate((value.value.args[0] as any).value);
+      }
+      throw new UnsupportedScalarConstructorError("plainDate", value.value.name, ["fromISO"]);
     case "plainTime":
-      return ScalarSerializers.plainTime((value.value.args[0] as any).value);
+      if (value.value.name === "fromISO") {
+        return ScalarSerializers.plainTime((value.value.args[0] as any).value);
+      }
+      throw new UnsupportedScalarConstructorError("plainTime", value.value.name, ["fromISO"]);
     case "duration":
-      return ScalarSerializers.duration((value.value.args[0] as any).value, encodeAs);
+      if (value.value.name === "fromISO") {
+        return ScalarSerializers.duration((value.value.args[0] as any).value, encodeAs);
+      }
+      throw new UnsupportedScalarConstructorError("duration", value.value.name, ["fromISO"]);
   }
 }
 

packages/compiler/src/lib/examples.ts

@@ -107,8 +107,18 @@ export function fromSdkType<T extends SdkType>(
       retVar = fromSdkArrayType(sdkContext, sdkType);
       break;
     case "constant":
+      // Don't transform optional Content-Type headers into enums - keep them as constants
+      const isContentTypeHeader =
+        sdkProperty &&
+        "kind" in sdkProperty &&
+        sdkProperty.kind === "header" &&
+        "serializedName" in sdkProperty &&
+        typeof sdkProperty.serializedName === "string" &&
+        sdkProperty.serializedName.toLocaleLowerCase() === "content-type";
+
       if (
         sdkProperty &&
+        !isContentTypeHeader &&
         (sdkProperty.optional || sdkProperty?.type.kind === "nullable") &&
         sdkProperty?.type.kind !== "boolean" &&
         sdkType.valueType.kind !== "boolean"

packages/http-client-csharp/emitter/src/lib/type-converter.ts

@@ -366,5 +366,95 @@ describe("Operation Converter", () => {
         strictEqual(response.bodyType, undefined);
       });
     });
+
+    describe("Optional Content-Type header", () => {
+      it("Optional body should have Content-Type remain as Constant (not transformed to enum)", async () => {
+        const program = await typeSpecCompile(
+          `
+          model BodyModel {
+            name: string;
+          }
+          
+          @post
+          op withOptionalBody(@body body?: BodyModel): void;
+          `,
+          runner,
+        );
+        const context = createEmitterContext(program);
+        const sdkContext = await createCSharpSdkContext(context);
+        const root = createModel(sdkContext);
+
+        strictEqual(root.clients.length, 1);
+        strictEqual(root.clients[0].methods.length, 1);
+
+        const method = root.clients[0].methods[0];
+        ok(method);
+
+        // validate operation
+        const operation = method.operation;
+        ok(operation);
+
+        // Find Content-Type parameter
+        const contentTypeParam = operation.parameters.find((p) => p.name === "contentType");
+        ok(contentTypeParam, "Content-Type parameter should exist");
+        strictEqual(contentTypeParam.kind, "header");
+        strictEqual(contentTypeParam.serializedName, "Content-Type");
+        strictEqual(contentTypeParam.optional, true, "Content-Type should be optional");
+        strictEqual(
+          contentTypeParam.scope,
+          "Constant",
+          "Content-Type should remain Constant scope",
+        );
+        strictEqual(
+          contentTypeParam.type.kind,
+          "constant",
+          "Content-Type should remain a constant type, not transformed to enum",
+        );
+      });
+
+      it("Required body should have Content-Type with Constant scope", async () => {
+        const program = await typeSpecCompile(
+          `
+          model BodyModel {
+            name: string;
+          }
+          
+          @post
+          op withRequiredBody(@body body: BodyModel): void;
+          `,
+          runner,
+        );
+        const context = createEmitterContext(program);
+        const sdkContext = await createCSharpSdkContext(context);
+        const root = createModel(sdkContext);
+
+        strictEqual(root.clients.length, 1);
+        strictEqual(root.clients[0].methods.length, 1);
+
+        const method = root.clients[0].methods[0];
+        ok(method);
+
+        // validate operation
+        const operation = method.operation;
+        ok(operation);
+
+        // Find Content-Type parameter
+        const contentTypeParam = operation.parameters.find((p) => p.name === "contentType");
+        ok(contentTypeParam, "Content-Type parameter should exist");
+        strictEqual(contentTypeParam.kind, "header");
+        strictEqual(contentTypeParam.serializedName, "Content-Type");
+        strictEqual(contentTypeParam.optional, false, "Content-Type should be required");
+        strictEqual(
+          contentTypeParam.scope,
+          "Constant",
+          "Content-Type should have Constant scope for required body",
+        );
+        strictEqual(
+          contentTypeParam.type.kind,
+          "constant",
+          "Content-Type should be a constant type",
+        );
+      });
+    });
   });
 });