chore: add batch example

examples/batch.ts

@@ -0,0 +1,66 @@
+import * as C from "../mod.ts";
+import * as T from "../test_util/mod.ts";
+import * as U from "../util/mod.ts";
+
+const recipients = [T.bob, T.charlie, T.dave, T.eve];
+const balances = C.ls(
+  ...recipients.map(({ publicKey }) => {
+    return C.entryRead(T.westend, "System", "Account", [publicKey])
+      .access("value")
+      .access("data")
+      .access("free")
+      .as<bigint>();
+  }),
+);
+
+const extrinsic = new C.Extrinsic(T.westend, {
+  sender: {
+    type: "Id",
+    value: T.alice.publicKey,
+  },
+  palletName: "Utility",
+  methodName: "batch_all",
+  args: {
+    calls: recipients.map(({ publicKey }) => ({
+      type: "Balances",
+      value: {
+        type: "transfer",
+        dest: {
+          type: "Id",
+          value: publicKey,
+        },
+        value: 12345n,
+      },
+    })),
+  },
+})
+  .signed((message) => ({
+    type: "Sr25519",
+    value: T.alice.sign(message),
+  }))
+  .watch((stop) => {
+    return (event) => {
+      if (typeof event.params.result === "string") {
+        console.log("Extrinsic", event.params.result);
+      } else {
+        if (event.params.result.inBlock) {
+          console.log("Extrinsic in block", event.params.result.inBlock);
+        } else if (event.params.result.finalized) {
+          console.log("Extrinsic finalized as of", event.params.result.finalized);
+          stop();
+        } else {
+          console.log("Misc", event.params.result);
+          stop();
+        }
+      }
+    };
+  });
+
+const initialBalances = U.throwIfError(await C.run(balances));
+U.throwIfError(await C.run(extrinsic));
+const balancesAfterExtrinsicFinalized = U.throwIfError(await C.run(balances));
+
+console.log({
+  initialBalances,
+  balancesAfterExtrinsicFinalized,
+});