Add multipart explicit part support in autorest (#902)

Add support for microsoft/typespec#3342 in
autorest emitter

.chronus/changes/uptake-multipartv2-2024-4-22-16-3-12.2.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: internal
+packages:
+  - "@azure-tools/typespec-azure-resource-manager"
+  - "@azure-tools/typespec-client-generator-core"
+  - "@azure-tools/typespec-azure-core"
+---

.chronus/changes/uptake-multipartv2-2024-4-22-16-3-12.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-autorest"
+---
+
+Add support for new multipart constructs in http library

eng/pipelines/templates/install.yml

@@ -9,7 +9,7 @@ parameters:
 steps:
   - task: UseDotNet@2
     inputs:
-      version: 6.0.x
+      version: 8.0.x
 
   - task: NodeTool@0
     inputs:

packages/typespec-autorest/src/openapi.ts

@@ -90,9 +90,10 @@ import {
   Authentication,
   HttpAuth,
   HttpOperation,
+  HttpOperationBody,
+  HttpOperationMultipartBody,
   HttpOperationParameters,
   HttpOperationResponse,
-  HttpOperationResponseBody,
   HttpStatusCodeRange,
   HttpStatusCodesEntry,
   MetadataInfo,
@@ -128,6 +129,7 @@ import { sortWithJsonSchema } from "./json-schema-sorter/sorter.js";
 import { createDiagnostic, reportDiagnostic } from "./lib.js";
 import {
   OpenAPI2Document,
+  OpenAPI2FileSchema,
   OpenAPI2FormDataParameter,
   OpenAPI2HeaderDefinition,
   OpenAPI2OAuth2FlowType,
@@ -717,7 +719,7 @@ export async function getOpenAPIForService(
       openapiResponse["x-ms-error-response"] = true;
     }
     const contentTypes: string[] = [];
-    let body: HttpOperationResponseBody | undefined;
+    let body: HttpOperationBody | HttpOperationMultipartBody | undefined;
     for (const data of response.responses) {
       if (data.headers && Object.keys(data.headers).length > 0) {
         openapiResponse.headers ??= {};
@@ -739,13 +741,7 @@ export async function getOpenAPIForService(
     }
 
     if (body) {
-      const isBinary = contentTypes.every((t) => isBinaryPayload(body!.type, t));
-      openapiResponse.schema = isBinary
-        ? { type: "file" }
-        : getSchemaOrRef(body.type, {
-            visibility: Visibility.Read,
-            ignoreMetadataAnnotations: body.isExplicit && body.containsMetadataAnnotations,
-          });
+      openapiResponse.schema = getSchemaForResponseBody(body, contentTypes);
     }
 
     for (const contentType of contentTypes) {
@@ -755,6 +751,24 @@ export async function getOpenAPIForService(
     currentEndpoint.responses![statusCode] = openapiResponse;
   }
 
+  function getSchemaForResponseBody(
+    body: HttpOperationBody | HttpOperationMultipartBody,
+    contentTypes: string[]
+  ): OpenAPI2Schema | OpenAPI2FileSchema {
+    const isBinary = contentTypes.every((t) => isBinaryPayload(body!.type, t));
+    if (isBinary) {
+      return { type: "file" };
+    }
+    if (body.bodyKind === "multipart") {
+      // OpenAPI2 doesn't support multipart responses, so we just return a string schema
+      return { type: "string" };
+    }
+    return getSchemaOrRef(body.type, {
+      visibility: Visibility.Read,
+      ignoreMetadataAnnotations: body.isExplicit && body.containsMetadataAnnotations,
+    });
+  }
+
   function getResponseHeader(prop: ModelProperty): OpenAPI2HeaderDefinition {
     const header: any = {};
     populateParameter(header, prop, "header", {
@@ -954,39 +968,81 @@ export async function getOpenAPIForService(
     }
 
     if (methodParams.body && !isVoidType(methodParams.body.type)) {
-      const isBinary = isBinaryPayload(methodParams.body.type, consumes);
-      const schemaContext = {
-        visibility,
-        ignoreMetadataAnnotations:
-          methodParams.body.isExplicit && methodParams.body.containsMetadataAnnotations,
-      };
-      const schema = isBinary
-        ? { type: "string", format: "binary" }
-        : getSchemaOrRef(methodParams.body.type, schemaContext);
-
-      if (currentConsumes.has("multipart/form-data")) {
-        const bodyModelType = methodParams.body.type;
-        // Assert, this should never happen. Rest library guard against that.
-        compilerAssert(bodyModelType.kind === "Model", "Body should always be a Model.");
-        if (bodyModelType) {
-          for (const param of bodyModelType.properties.values()) {
-            emitParameter(param, "formData", schemaContext, getJsonName(param));
-          }
+      emitBodyParameters(methodParams.body, visibility);
+    }
+  }
+
+  function emitBodyParameters(
+    body: HttpOperationBody | HttpOperationMultipartBody,
+    visibility: Visibility
+  ) {
+    switch (body.bodyKind) {
+      case "single":
+        emitSingleBodyParameters(body, visibility);
+        break;
+      case "multipart":
+        emitMultipartBodyParameters(body, visibility);
+        break;
+    }
+  }
+
+  function emitSingleBodyParameters(body: HttpOperationBody, visibility: Visibility) {
+    const isBinary = isBinaryPayload(body.type, body.contentTypes);
+    const schemaContext = {
+      visibility,
+      ignoreMetadataAnnotations: body.isExplicit && body.containsMetadataAnnotations,
+    };
+    const schema = isBinary
+      ? { type: "string", format: "binary" }
+      : getSchemaOrRef(body.type, schemaContext);
+
+    if (currentConsumes.has("multipart/form-data")) {
+      const bodyModelType = body.type;
+      // Assert, this should never happen. Rest library guard against that.
+      compilerAssert(bodyModelType.kind === "Model", "Body should always be a Model.");
+      if (bodyModelType) {
+        for (const param of bodyModelType.properties.values()) {
+          emitParameter(param, "formData", schemaContext, getJsonName(param));
+        }
+      }
+    } else if (body.property) {
+      emitParameter(
+        body.property,
+        "body",
+        { visibility, ignoreMetadataAnnotations: false },
+        getJsonName(body.property),
+        schema
+      );
+    } else {
+      currentEndpoint.parameters.push({
+        name: "body",
+        in: "body",
+        schema,
+        required: true,
+      });
+    }
+  }
+
+  function emitMultipartBodyParameters(body: HttpOperationMultipartBody, visibility: Visibility) {
+    for (const [index, part] of body.parts.entries()) {
+      const partName = part.name ?? `part${index}`;
+      let schema = getFormDataSchema(
+        part.body.type,
+        { visibility, ignoreMetadataAnnotations: false },
+        partName
+      );
+      if (schema) {
+        if (part.multi) {
+          schema = {
+            type: "array",
+            items: schema.type === "file" ? { type: "string", format: "binary" } : schema,
+          };
         }
-      } else if (methodParams.body.parameter) {
-        emitParameter(
-          methodParams.body.parameter,
-          "body",
-          { visibility, ignoreMetadataAnnotations: false },
-          getJsonName(methodParams.body.parameter),
-          schema
-        );
-      } else {
         currentEndpoint.parameters.push({
-          name: "body",
-          in: "body",
-          schema,
-          required: true,
+          name: partName,
+          in: "formData",
+          required: !part.optional,
+          ...schema,
         });
       }
     }

packages/typespec-autorest/src/openapi2-document.ts

@@ -285,6 +285,18 @@ export type OpenAPI2Schema = Extensions & {
   "x-ms-mutability"?: string[];
 };
 
+export type OpenAPI2FileSchema = {
+  type: "file";
+  format?: string;
+  title?: string;
+  description?: string;
+  default?: unknown;
+  required?: string[];
+  readonly?: boolean;
+  externalDocs?: OpenAPI2ExternalDocs;
+  example?: unknown;
+};
+
 export type OpenAPI2ParameterType = OpenAPI2Parameter["in"];
 
 export interface OpenAPI2HeaderDefinition {
@@ -465,7 +477,7 @@ export interface OpenAPI2Response {
   /** A short description of the response. Commonmark syntax can be used for rich text representation */
   description: string;
   /** A definition of the response structure. It can be a primitive, an array or an object. If this field does not exist, it means no content is returned as part of the response. As an extension to the Schema Object, its root type value may also be "file". This SHOULD be accompanied by a relevant produces mime-type. */
-  schema?: OpenAPI2Schema;
+  schema?: OpenAPI2Schema | OpenAPI2FileSchema;
   /** A list of headers that are sent with the response. */
   headers?: Record<string, OpenAPI2HeaderDefinition>;
   /** An example of the response message. */

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

@@ -2,7 +2,105 @@ import { deepStrictEqual } from "assert";
 import { describe, it } from "vitest";
 import { openApiFor } from "./test-host.js";
 
-describe("typespec-autorest: multipart", () => {
+it("model properties are spread into individual parameters", async () => {
+  const res = await openApiFor(
+    `
+    model Form { name: HttpPart<string>, profileImage: HttpPart<bytes> }
+    op upload(@header contentType: "multipart/form-data", @multipartBody body: Form): void;
+    `
+  );
+  const op = res.paths["/"].post;
+  deepStrictEqual(op.parameters, [
+    {
+      in: "formData",
+      name: "name",
+      required: true,
+      type: "string",
+    },
+    {
+      in: "formData",
+      name: "profileImage",
+      required: true,
+      type: "file",
+    },
+  ]);
+});
+
+it("part of type `bytes` produce `type: file`", async () => {
+  const res = await openApiFor(
+    `
+    op upload(@header contentType: "multipart/form-data", @multipartBody body: { profileImage: HttpPart<bytes> }): void;
+    `
+  );
+  const op = res.paths["/"].post;
+  deepStrictEqual(op.parameters, [
+    {
+      in: "formData",
+      name: "profileImage",
+      required: true,
+      type: "file",
+    },
+  ]);
+});
+
+it("part of type `bytes[]` produce `type: array, items: { type: string, format: binary }`", async () => {
+  const res = await openApiFor(
+    `
+    op upload(@header contentType: "multipart/form-data", @multipartBody _: { profileImage: HttpPart<bytes>[]}): void;
+    `
+  );
+  const op = res.paths["/"].post;
+  deepStrictEqual(op.parameters, [
+    {
+      in: "formData",
+      name: "profileImage",
+      required: true,
+      type: "array",
+      items: {
+        type: "string",
+        format: "binary",
+      },
+    },
+  ]);
+});
+
+it("part of type `string` produce `type: string`", async () => {
+  const res = await openApiFor(
+    `
+    op upload(@header contentType: "multipart/form-data", @multipartBody body: { name: HttpPart<string> }): void;
+    `
+  );
+  const op = res.paths["/"].post;
+  deepStrictEqual(op.parameters, [
+    {
+      in: "formData",
+      name: "name",
+      required: true,
+      type: "string",
+    },
+  ]);
+});
+
+// https://github.com/Azure/typespec-azure/issues/3860
+it("part of type `object` produce `type: string`", async () => {
+  const res = await openApiFor(
+    `
+    #suppress "@azure-tools/typespec-autorest/unsupported-multipart-type" "For test"
+    op upload(@header contentType: "multipart/form-data", @multipartBody _: { address: HttpPart<{city: string, street: string}>}): void;
+    `
+  );
+  const op = res.paths["/"].post;
+  deepStrictEqual(op.parameters, [
+    {
+      in: "formData",
+      name: "address",
+      required: true,
+      type: "string",
+    },
+  ]);
+});
+
+describe("legacy implicit form", () => {
   it("part of type `bytes` produce `type: file`", async () => {
     const res = await openApiFor(
       `

packages/typespec-azure-core/src/lro-info.ts

@@ -137,8 +137,8 @@ export function getLroOperationInfo(
   }
   if (targetParameters.body) {
     const body = targetParameters.body;
-    if (body.parameter) {
-      targetProperties.set(body.parameter.name, body.parameter);
+    if (body.bodyKind === "single" && body.property) {
+      targetProperties.set(body.property.name, body.property);
     } else if (body.type.kind === "Model") {
       for (const [name, param] of getAllProperties(body.type)) {
         targetProperties.set(name, param);

packages/typespec-azure-core/test/test-host.ts

@@ -102,7 +102,7 @@ export async function getSimplifiedOperations(
       params: {
         params: r.parameters.parameters.map(({ type, name }) => ({ type, name })),
         body:
-          r.parameters.body?.parameter?.name ??
+          r.parameters.body?.property?.name ??
           (r.parameters.body?.type?.kind === "Model"
             ? Array.from(r.parameters.body.type.properties.keys())
             : undefined),

packages/typespec-azure-playground-website/samples/azure-core.tsp

@@ -256,7 +256,7 @@ interface WidgetParts {
   reorderParts is Operations.LongRunningResourceCollectionAction<
     WidgetPart,
     WidgetPartReorderRequest,
-    TypeSpec.Http.AcceptedResponse
+    never
   >;
 }
 

packages/typespec-azure-resource-manager/src/rules/arm-post-response-codes.ts

@@ -1,7 +1,11 @@
 import { Program, createRule } from "@typespec/compiler";
 
 import { getLroMetadata } from "@azure-tools/typespec-azure-core";
-import { HttpOperationBody, HttpOperationResponse } from "@typespec/http";
+import {
+  HttpOperationBody,
+  HttpOperationMultipartBody,
+  HttpOperationResponse,
+} from "@typespec/http";
 import { ArmResourceOperation } from "../operations.js";
 import { getArmResources } from "../resource.js";
 
@@ -20,7 +24,7 @@ export const armPostResponseCodesRule = createRule({
   create(context) {
     function getResponseBody(
       response: HttpOperationResponse | undefined
-    ): HttpOperationBody | undefined {
+    ): HttpOperationBody | HttpOperationMultipartBody | undefined {
       if (response === undefined) return undefined;
       if (response.responses.length > 1) {
         throw new Error("Multiple responses are not supported.");