feat: add balance command

book/src/ref/commands.md

@@ -16,6 +16,7 @@ Starkli offers the following commands:
 - state-update
 - transaction-receipt
 - chain-id
+- balance
 - nonce
 - storage
 - class-hash-at

src/main.rs

@@ -64,6 +64,8 @@ enum Subcommands {
     TransactionReceipt(TransactionReceipt),
     #[clap(about = "Get Starknet network ID")]
     ChainId(ChainId),
+    #[clap(about = "Get native gas token (currently ETH) balance")]
+    Balance(Balance),
     #[clap(about = "Get nonce for a certain contract")]
     Nonce(Nonce),
     #[clap(about = "Get storage value for a slot at a contract")]
@@ -135,6 +137,7 @@ async fn run_command(cli: Cli) -> Result<()> {
         Subcommands::StateUpdate(cmd) => cmd.run().await,
         Subcommands::TransactionReceipt(cmd) => cmd.run().await,
         Subcommands::ChainId(cmd) => cmd.run().await,
+        Subcommands::Balance(cmd) => cmd.run().await,
         Subcommands::Nonce(cmd) => cmd.run().await,
         Subcommands::Storage(cmd) => cmd.run().await,
         Subcommands::ClassHashAt(cmd) => cmd.run().await,

src/subcommands/balance.rs

@@ -0,0 +1,90 @@
+use std::sync::Arc;
+
+use anyhow::Result;
+use bigdecimal::BigDecimal;
+use clap::Parser;
+use num_bigint::{BigUint, ToBigInt};
+use starknet::{
+    core::types::{BlockId, BlockTag, FieldElement, FunctionCall},
+    macros::selector,
+    providers::Provider,
+};
+
+use crate::{
+    address_book::AddressBookResolver, decode::FeltDecoder, verbosity::VerbosityArgs, ProviderArgs,
+};
+
+/// The default ETH address: 0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7.
+const DEFAULT_ETH_ADDRESS: FieldElement = FieldElement::from_mont([
+    4380532846569209554,
+    17839402928228694863,
+    17240401758547432026,
+    418961398025637529,
+]);
+
+#[derive(Debug, Parser)]
+pub struct Balance {
+    #[clap(flatten)]
+    provider: ProviderArgs,
+    #[clap(help = "Account address")]
+    account_address: String,
+    #[clap(
+        long,
+        conflicts_with = "hex",
+        help = "Display raw balance amount in integer"
+    )]
+    raw: bool,
+    #[clap(
+        long,
+        conflicts_with = "raw",
+        help = "Display balance amount in hexadecimal representation"
+    )]
+    hex: bool,
+    #[clap(flatten)]
+    verbosity: VerbosityArgs,
+}
+
+impl Balance {
+    pub async fn run(self) -> Result<()> {
+        self.verbosity.setup_logging();
+
+        let provider = Arc::new(self.provider.into_provider());
+        let felt_decoder = FeltDecoder::new(AddressBookResolver::new(provider.clone()));
+
+        let account_address = felt_decoder
+            .decode_single_with_addr_fallback(&self.account_address)
+            .await?;
+
+        let result = provider
+            .call(
+                FunctionCall {
+                    contract_address: DEFAULT_ETH_ADDRESS,
+                    entry_point_selector: selector!("balanceOf"),
+                    calldata: vec![account_address],
+                },
+                BlockId::Tag(BlockTag::Pending),
+            )
+            .await?;
+
+        if result.len() != 2 {
+            anyhow::bail!("unexpected call result size: {}", result.len());
+        }
+
+        let low = BigUint::from_bytes_be(&result[0].to_bytes_be());
+        let high = BigUint::from_bytes_be(&result[1].to_bytes_be());
+
+        let raw_balance: BigUint = (high << 128) + low;
+
+        if self.raw {
+            println!("{}", raw_balance);
+        } else if self.hex {
+            println!("{:#x}", raw_balance);
+        } else {
+            // `to_bigint()` from `BigUint` always returns `Some`.
+            let balance_dec = BigDecimal::new(raw_balance.to_bigint().unwrap(), 18);
+            println!("{}", balance_dec);
+        }
+
+        Ok(())
+    }
+}

src/subcommands/mod.rs

@@ -49,6 +49,9 @@ pub use class_at::ClassAt;
 mod class_hash_at;
 pub use class_hash_at::ClassHashAt;
 
+mod balance;
+pub use balance::Balance;
+
 mod nonce;
 pub use nonce::Nonce;