[core-http] Add NDJSON support

sdk/core/core-http/review/core-http.api.md

@@ -351,6 +351,7 @@ export interface InternalPipelineOptions extends PipelineOptions {
     decompressResponse?: boolean;
     deserializationOptions?: DeserializationOptions;
     loggingOptions?: LogPolicyOptions;
+    sendStreamingJson?: boolean;
 }
 
 // @public

sdk/core/core-http/src/pipelineOptions.ts

@@ -67,4 +67,9 @@ export interface InternalPipelineOptions extends PipelineOptions {
    * Configure whether to decompress response according to Accept-Encoding header (node-fetch only)
    */
   decompressResponse?: boolean;
+
+  /**
+   * Send JSON Array payloads as NDJSON.
+   */
+  sendStreamingJson?: boolean;
 }

sdk/core/core-http/src/policies/ndJsonPolicy.ts

@@ -0,0 +1,51 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+// BaseRequestPolicy has a protected constructor.
+/* eslint-disable @typescript-eslint/no-useless-constructor */
+
+import {
+  BaseRequestPolicy,
+  RequestPolicy,
+  RequestPolicyOptions,
+  RequestPolicyFactory
+} from "./requestPolicy";
+import { WebResourceLike } from "../webResource";
+import { HttpOperationResponse } from "../httpOperationResponse";
+
+export function ndJsonPolicy(): RequestPolicyFactory {
+  return {
+    create: (nextPolicy: RequestPolicy, options: RequestPolicyOptions) => {
+      return new NdJsonPolicy(nextPolicy, options);
+    }
+  };
+}
+
+/**
+ * NdJsonPolicy that formats a JSON array as newline-delimited JSON
+ */
+class NdJsonPolicy extends BaseRequestPolicy {
+  /**
+   * Creates an instance of KeepAlivePolicy.
+   *
+   * @param nextPolicy
+   * @param options
+   */
+  constructor(nextPolicy: RequestPolicy, options: RequestPolicyOptions) {
+    super(nextPolicy, options);
+  }
+
+  /**
+   * Sends a request.
+   *
+   * @param request
+   */
+  public async sendRequest(request: WebResourceLike): Promise<HttpOperationResponse> {
+    // There currently isn't a good way to bypass the serializer
+    const body = JSON.parse(request.body);
+    if (Array.isArray(body)) {
+      request.body = body.map((item) => JSON.stringify(item) + "\n").join("");
+    }
+    return this._nextPolicy.sendRequest(request);
+  }
+}

sdk/core/core-http/src/serviceClient.ts

@@ -59,6 +59,7 @@ import { InternalPipelineOptions } from "./pipelineOptions";
 import { DefaultKeepAliveOptions, keepAlivePolicy } from "./policies/keepAlivePolicy";
 import { tracingPolicy } from "./policies/tracingPolicy";
 import { disableResponseDecompressionPolicy } from "./policies/disableResponseDecompressionPolicy";
+import { ndJsonPolicy } from "./policies/ndJsonPolicy";
 
 /**
  * Options to configure a proxy for outgoing requests (Node.js only).
@@ -677,6 +678,10 @@ export function createPipelineFromOptions(
 ): ServiceClientOptions {
   const requestPolicyFactories: RequestPolicyFactory[] = [];
 
+  if (pipelineOptions.sendStreamingJson) {
+    requestPolicyFactories.push(ndJsonPolicy());
+  }
+
   let userAgentValue = undefined;
   if (pipelineOptions.userAgentOptions && pipelineOptions.userAgentOptions.userAgentPrefix) {
     const userAgentInfo: string[] = [];

sdk/core/core-http/test/policies/ndJsonPolicyTests.ts

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+import { assert } from "chai";
+import { RequestPolicyOptions } from "../../src/policies/requestPolicy";
+import { WebResource } from "../../src/webResource";
+import { HttpHeaders } from "../../src/httpHeaders";
+import { ndJsonPolicy } from "../../src/policies/ndJsonPolicy";
+
+describe("NdJsonPolicy", function() {
+  const returnOk = {
+    sendRequest: async (request: WebResource) => {
+      return {
+        request,
+        status: 200,
+        headers: new HttpHeaders()
+      };
+    }
+  };
+
+  const emptyPolicyOptions = new RequestPolicyOptions();
+
+  it("Formats arrays correctly", async function() {
+    const factory = ndJsonPolicy();
+    const policy = factory.create(returnOk, emptyPolicyOptions);
+    const request = new WebResource();
+    request.body = JSON.stringify([{ a: 1 }, { b: 2 }, { c: 3 }]);
+    const result = await policy.sendRequest(request);
+    assert.strictEqual(result.request.body, `{"a":1}\n{"b":2}\n{"c":3}\n`);
+  });
+});