add getVaa function

pyth-common-js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@pythnetwork/pyth-common-js",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "Pyth Network Common Utils in JS",
   "author": {
     "name": "Pyth Data Association"

pyth-common-js/src/PriceServiceConnection.ts

@@ -149,6 +149,30 @@ export class PriceServiceConnection {
     return response.data;
   }
 
+  /**
+   * Fetch the earliest VAA of the given price id that is published since the given publish time.
+   * This will throw an error if the given publish time is in the future, or if the price service does not have a db backend.
+   * This will throw an axios error if there is a network problem or the price service returns a non-ok response (e.g: Invalid price id)
+   *
+   * This function is coupled to wormhole implemntation.
+   *
+   * @param priceId Hex-encoded price id.
+   * @param publishTime Epoch timestamp in seconds.
+   * @returns Tuple of VAA and publishTime.
+   */
+  async getVaa(
+    priceId: HexString,
+    publishTime: EpochTimeStamp
+  ): Promise<[string, EpochTimeStamp]> {
+    const response = await this.httpClient.get("/api/get_vaa", {
+      params: {
+        id: priceId,
+        publish_time: publishTime,
+      },
+    });
+    return [response.data.vaa, response.data.publishTime];
+  }
+
   /**
    * Fetch the list of available price feed ids.
    * This will throw an axios error if there is a network problem or the price service returns a non-ok response.