[apps/cli] set defaults for fee-amount, fee-token and gas-limit tx args

apps/src/lib/cli.rs

@@ -1126,11 +1126,14 @@ pub mod args {
     const DONT_ARCHIVE: ArgFlag = flag("dont-archive");
     const DRY_RUN_TX: ArgFlag = flag("dry-run");
     const EPOCH: ArgOpt<Epoch> = arg_opt("epoch");
-    const FEE_AMOUNT: Arg<token::Amount> = arg("fee-amount");
-    const FEE_TOKEN: Arg<WalletAddress> = arg("fee-token");
+    const FEE_AMOUNT: ArgDefault<token::Amount> =
+        arg_default("fee-amount", DefaultFn(|| token::Amount::from(0)));
+    const FEE_TOKEN: ArgDefaultFromCtx<WalletAddress> =
+        arg_default_from_ctx("fee-token", DefaultFn(|| "XAN".into()));
     const FILTER_PATH: ArgOpt<PathBuf> = arg_opt("filter-path");
     const FORCE: ArgFlag = flag("force");
-    const GAS_LIMIT: Arg<token::Amount> = arg("gas-limit");
+    const GAS_LIMIT: ArgDefault<token::Amount> =
+        arg_default("gas-limit", DefaultFn(|| token::Amount::from(0)));
     const GENESIS_PATH: Arg<PathBuf> = arg("genesis-path");
     const LEDGER_ADDRESS_ABOUT: &str =
         "Address of a ledger node as \"{scheme}://{host}:{port}\". If the \

apps/src/lib/cli/utils.rs

@@ -60,6 +60,12 @@ pub struct ArgDefault<T> {
     pub r#type: PhantomData<T>,
 }
 
+pub struct ArgDefaultFromCtx<T> {
+    pub name: &'static str,
+    pub default: DefaultFn<String>,
+    pub r#type: PhantomData<T>,
+}
+
 /// This wrapper type is a workaround for "function pointers in const fn are
 /// unstable", which allows us to use this type in a const fn, because the
 /// type-checker doesn't inspect the wrapped type.
@@ -100,6 +106,17 @@ pub const fn arg_default<T>(
     }
 }
 
+pub const fn arg_default_from_ctx<T>(
+    name: &'static str,
+    default: DefaultFn<String>,
+) -> ArgDefaultFromCtx<T> {
+    ArgDefaultFromCtx {
+        name,
+        default,
+        r#type: PhantomData,
+    }
+}
+
 pub const fn flag(name: &'static str) -> ArgFlag {
     ArgFlag { name }
 }
@@ -201,6 +218,24 @@ where
     }
 }
 
+impl<T> ArgDefaultFromCtx<FromContext<T>>
+where
+    T: FromStr,
+    <T as FromStr>::Err: Debug,
+{
+    pub fn def(&self) -> ClapArg {
+        ClapArg::new(self.name).long(self.name).takes_value(true)
+    }
+
+    pub fn parse(&self, matches: &ArgMatches) -> FromContext<T> {
+        let raw = parse_opt(matches, self.name).unwrap_or_else(|| {
+            let DefaultFn(default) = self.default;
+            default()
+        });
+        FromContext::new(raw)
+    }
+}
+
 impl ArgFlag {
     pub fn def(&self) -> ClapArg {
         ClapArg::new(self.name).long(self.name).takes_value(false)