Fix handling of non-existent ID in getTx

packages/bcp/src/cosmwasmconnection.spec.ts

@@ -10,6 +10,7 @@ import {
   PubkeyBytes,
   SendTransaction,
   TokenTicker,
+  TransactionId,
   TransactionState,
 } from "@iov/bcp";
 import { Random, Secp256k1 } from "@iov/crypto";
@@ -264,6 +265,21 @@ describe("CosmWasmConnection", () => {
     });
   });
 
+  describe("getTx", () => {
+    it("throws for non-existent transaction", async () => {
+      pendingWithoutCosmos();
+      const connection = await CosmWasmConnection.establish(httpUrl, defaultPrefix, defaultConfig);
+
+      const nonExistentId = "0000000000000000000000000000000000000000000000000000000000000000" as TransactionId;
+      await connection.getTx(nonExistentId).then(
+        () => fail("this must not succeed"),
+        error => expect(error).toMatch(/transaction does not exist/i),
+      );
+
+      connection.disconnect();
+    });
+  });
+
   describe("integration tests", () => {
     it("can post and get a transaction", async () => {
       pendingWithoutCosmos();

packages/bcp/src/cosmwasmconnection.ts

@@ -231,15 +231,14 @@ export class CosmWasmConnection implements BlockchainConnection {
   public async getTx(
     id: TransactionId,
   ): Promise<ConfirmedAndSignedTransaction<UnsignedTransaction> | FailedTransaction> {
-    try {
-      // tslint:disable-next-line: deprecation
-      const response = await this.restClient.txsById(id);
-      return this.parseAndPopulateTxResponseSigned(response);
-    } catch (error) {
-      if (error.response.status === 404) {
+    const results = await this.cosmWasmClient.searchTx({ id: id });
+    switch (results.length) {
+      case 0:
         throw new Error("Transaction does not exist");
-      }
-      throw error;
+      case 1:
+        return this.parseAndPopulateTxResponseSigned(results[0]);
+      default:
+        throw new Error("Got unexpected amount of search results");
     }
   }