fix: add getTransactionId method to the SynthesizeStream (#1058)

this method was present on the RecognizeStream and was mistakenly left off of the SynthesizeStream

Author: dpopp07

lib/recognize-stream.ts

@@ -19,7 +19,7 @@ import { Authenticator, contentType, qs } from 'ibm-cloud-sdk-core';
 import { Duplex, DuplexOptions } from 'stream';
 import { w3cwebsocket as w3cWebSocket } from 'websocket';
 import { RecognizeWebSocketParams } from '../speech-to-text/v1';
-import { processUserParameters } from './websocket-utils';
+import { extractTransactionId, processUserParameters } from './websocket-utils';
 
 interface WritableState {
   highWaterMark: number;
@@ -456,25 +456,7 @@ class RecognizeStream extends Duplex {
    * @return Promise<String>
    */
   getTransactionId(): Promise<string> {
-    return new Promise<string>((resolve, reject) => {
-      if (
-        this.socket &&
-        this.socket._client &&
-        this.socket._client.response &&
-        this.socket._client.response.headers
-      ) {
-        resolve(
-          (this.socket._client.response.headers['x-global-transaction-id'] as string)
-        );
-      } else {
-        this.on('open', () =>
-          resolve(
-            (this.socket._client.response.headers['x-global-transaction-id'] as string)
-          )
-        );
-        this.on('error', reject);
-      }
-    });
+    return extractTransactionId(this);
   }
 }
 

lib/synthesize-stream.ts

@@ -19,7 +19,7 @@ import { Authenticator, qs } from 'ibm-cloud-sdk-core';
 import { Readable, ReadableOptions } from 'stream';
 import { w3cwebsocket as w3cWebSocket } from 'websocket';
 import { SynthesizeWebSocketParams } from '../text-to-speech/v1';
-import { processUserParameters } from './websocket-utils';
+import { extractTransactionId, processUserParameters } from './websocket-utils';
 
 /**
  * pipe()-able Node.js Readable stream - accepts text in the constructor and emits binary audio data in its 'message' events
@@ -211,6 +211,17 @@ class SynthesizeStream extends Readable {
       }
     );
   }
+
+  /**
+   * Returns a Promise that resolves with Watson Transaction ID from the X-Transaction-ID header
+   *
+   * Works in Node.js but not in browsers (the W3C WebSocket API does not expose headers)
+   *
+   * @return Promise<String>
+   */
+  getTransactionId(): Promise<string> {
+    return extractTransactionId(this);
+  }
 }
 
 namespace SynthesizeStream {

lib/websocket-utils.ts

@@ -42,3 +42,34 @@ export function processUserParameters(options: any, allowedParams: string[]): an
 
   return processedOptions;
 }
+
+/**
+ * Pulls the transaction ID from the connection headers and returns it in a Promise.
+ * This function is used by the RecognizeStream and the SynthesizeStream - they both expose
+ * a method called `getTransactionId` that relies on this code to read the ID from the
+ * connection.
+ *
+ * @param {object} streamContext - the context (i.e. "this") of the invoking stream class
+ * @returns {Promise<string>} - Resolves with the transaction ID as a string
+ */
+export function extractTransactionId(streamContext: any) {
+  return new Promise<string>((resolve, reject) => {
+    if (
+      streamContext.socket &&
+      streamContext.socket._client &&
+      streamContext.socket._client.response &&
+      streamContext.socket._client.response.headers
+    ) {
+      resolve(
+        (streamContext.socket._client.response.headers['x-global-transaction-id'] as string)
+      );
+    } else {
+      streamContext.on('open', () =>
+        resolve(
+          (streamContext.socket._client.response.headers['x-global-transaction-id'] as string)
+        )
+      );
+      streamContext.on('error', reject);
+    }
+  });
+}