Add connectComet for auto-detecting the right client

CHANGELOG.md

@@ -10,6 +10,14 @@ and this project adheres to
 
 - @cosmjs/tendermint-rpc: Remove `Adaptor` abstractions which are not needed
   anymore by haing a dedicated client for each backend.
+- @cosmjs/tendermint-rpc: Add
+  `CometClient = Tendermint34Client | Tendermint37Client | Comet38Client` and
+  `connectComet` for auto-detecting the right client for a provided endpoint.
+
+### Deprecated
+
+- @cosmjs/tendermint-rpc: `CometClient` should be used instead of
+  `TendermintClient`.
 
 ## [0.31.1] - 2023-08-21
 

packages/tendermint-rpc/src/index.ts

@@ -99,7 +99,14 @@ export * as tendermint34 from "./tendermint34";
 export { Tendermint34Client } from "./tendermint34";
 export * as tendermint37 from "./tendermint37";
 export { Tendermint37Client } from "./tendermint37";
-export { isTendermint34Client, isTendermint37Client, TendermintClient } from "./tendermintclient";
+export {
+  CometClient,
+  connectComet,
+  isComet38Client,
+  isTendermint34Client,
+  isTendermint37Client,
+  TendermintClient,
+} from "./tendermintclient";
 export {
   BlockIdFlag,
   CommitSignature,

packages/tendermint-rpc/src/tendermintclient.ts

@@ -1,13 +1,47 @@
+import { Comet38Client } from "./comet38";
+import { HttpEndpoint } from "./rpcclients";
 import { Tendermint34Client } from "./tendermint34";
 import { Tendermint37Client } from "./tendermint37";
 
-/** A TendermintClient is either a Tendermint34Client or a Tendermint37Client */
+/**
+ * A TendermintClient is either a Tendermint34Client or a Tendermint37Client
+ *
+ * @deprecated use `CometClient`
+ */
 export type TendermintClient = Tendermint34Client | Tendermint37Client;
 
-export function isTendermint34Client(client: TendermintClient): client is Tendermint34Client {
+/** A CometClient is either a Tendermint34Client, Tendermint37Client or a Comet38Client */
+export type CometClient = Tendermint34Client | Tendermint37Client | Comet38Client;
+
+export function isTendermint34Client(client: CometClient): client is Tendermint34Client {
   return client instanceof Tendermint34Client;
 }
 
-export function isTendermint37Client(client: TendermintClient): client is Tendermint37Client {
+export function isTendermint37Client(client: CometClient): client is Tendermint37Client {
   return client instanceof Tendermint37Client;
 }
+
+export function isComet38Client(client: CometClient): client is Comet38Client {
+  return client instanceof Comet38Client;
+}
+
+/**
+ * Auto-detects the version of the backend and uses a suitable client.
+ */
+export async function connectComet(endpoint: string | HttpEndpoint): Promise<CometClient> {
+  // Tendermint/CometBFT 0.34/0.37/0.38 auto-detection. Starting with 0.37 we seem to get reliable versions again 🎉
+  // Using 0.34 as the fallback.
+  let out: CometClient;
+  const tm37Client = await Tendermint37Client.connect(endpoint);
+  const version = (await tm37Client.status()).nodeInfo.version;
+  if (version.startsWith("0.37.")) {
+    out = tm37Client;
+  } else if (version.startsWith("0.38.")) {
+    tm37Client.disconnect();
+    out = await Comet38Client.connect(endpoint);
+  } else {
+    tm37Client.disconnect();
+    out = await Tendermint34Client.connect(endpoint);
+  }
+  return out;
+}