From 8e4e6b139f1bfcebf170095d246bf71777cf0fc9 Mon Sep 17 00:00:00 2001
From: yancy <yancy@yancy.lol>
Date: Wed, 11 Dec 2024 15:22:43 -0600
Subject: [PATCH] Return result from method

Conditionally returns a result depending on the input.  This is in
preparation for changing the MAX and MIN values of SignedAmount.
---
 units/src/amount/serde.rs    |  4 +++-
 units/src/amount/signed.rs   | 24 +++++++++++++++++++++---
 units/src/amount/unsigned.rs |  2 +-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/units/src/amount/serde.rs b/units/src/amount/serde.rs
index 2caa8c74e7..afc4e02c78 100644
--- a/units/src/amount/serde.rs
+++ b/units/src/amount/serde.rs
@@ -135,7 +135,9 @@ impl SerdeAmount for SignedAmount {
         i64::serialize(&self.to_sat(), s)
     }
     fn des_sat<'d, D: Deserializer<'d>>(d: D, _: private::Token) -> Result<Self, D::Error> {
-        Ok(SignedAmount::from_sat(i64::deserialize(d)?))
+        use serde::de::Error;
+        SignedAmount::from_sat(i64::deserialize(d)?)
+            .map_err(D::Error::custom)
     }
     #[cfg(feature = "alloc")]
     fn ser_btc<S: Serializer>(self, s: S, _: private::Token) -> Result<S::Ok, S::Error> {
diff --git a/units/src/amount/signed.rs b/units/src/amount/signed.rs
index 69a6c340bf..cb7d67e117 100644
--- a/units/src/amount/signed.rs
+++ b/units/src/amount/signed.rs
@@ -63,7 +63,20 @@ impl SignedAmount {
     pub const MAX: SignedAmount = SignedAmount(i64::MAX);
 
     /// Constructs a new [`SignedAmount`] with satoshi precision and the given number of satoshis.
-    pub const fn from_sat(satoshi: i64) -> SignedAmount { SignedAmount(satoshi) }
+    ///
+    /// # Errors
+    ///
+    /// On values exceeding [`SignedAmount::MAX`] or less than [`SignedAmount::MIN`]
+    #[allow(clippy::absurd_extreme_comparisons)]
+    pub const fn from_sat(satoshi: i64) -> Result<SignedAmount, OutOfRangeError> {
+        if satoshi < Self::MIN.0 {
+            Err(OutOfRangeError { is_signed: true, is_greater_than_max: false })
+        } else if satoshi > Self::MAX.0 {
+            Err(OutOfRangeError { is_signed: true, is_greater_than_max: true })
+        } else {
+            Ok(SignedAmount(satoshi))
+        }
+    }
 
     /// Constructs a new [`SignedAmount`] with satoshi precision and the given number of satoshis.
     ///
@@ -98,7 +111,7 @@ impl SignedAmount {
     /// per bitcoin overflows an `i64` type.
     pub fn from_int_btc(btc: i64) -> Result<SignedAmount, OutOfRangeError> {
         match btc.checked_mul(100_000_000) {
-            Some(amount) => Ok(SignedAmount::from_sat(amount)),
+            Some(amount) => SignedAmount::from_sat(amount),
             None => Err(OutOfRangeError { is_signed: true, is_greater_than_max: true }),
         }
     }
@@ -112,7 +125,12 @@ impl SignedAmount {
     /// per bitcoin overflows an `i64` type.
     pub const fn from_int_btc_const(btc: i64) -> SignedAmount {
         match btc.checked_mul(100_000_000) {
-            Some(amount) => SignedAmount::from_sat(amount),
+            Some(amount) => {
+                match SignedAmount::from_sat(amount) {
+                    Ok(sa) => sa,
+                    Err(_) => panic!("checked_mul overflow")
+                }
+            }
             None => panic!("checked_mul overflowed"),
         }
     }
diff --git a/units/src/amount/unsigned.rs b/units/src/amount/unsigned.rs
index f51ae4af35..b57a568130 100644
--- a/units/src/amount/unsigned.rs
+++ b/units/src/amount/unsigned.rs
@@ -345,7 +345,7 @@ impl Amount {
         if self.to_sat() > SignedAmount::MAX.to_sat() as u64 {
             Err(OutOfRangeError::too_big(true))
         } else {
-            Ok(SignedAmount::from_sat(self.to_sat() as i64))
+            SignedAmount::from_sat(self.to_sat() as i64)
         }
     }