Minor review comments

Author: optout21

lightning-invoice/src/de.rs

@@ -54,7 +54,7 @@ impl<const N: usize> FromBase32 for [u8; N] {
 			Bolt11ParseError::InvalidSliceLength(
 				data.len(),
 				(N * 8 + 4) / 5,
-				"<[u8; N]>::from_base32()".into(),
+				"<[u8; N]>",
 			)
 		})
 	}
@@ -68,7 +68,7 @@ impl FromBase32 for PaymentSecret {
 			return Err(Bolt11ParseError::InvalidSliceLength(
 				field_data.len(),
 				52,
-				"PaymentSecret::from_base32()".into(),
+				"payment secret",
 			));
 		}
 		let data_bytes = <[u8; 32]>::from_base32(field_data)?;
@@ -456,7 +456,7 @@ impl FromBase32 for PositiveTimestamp {
 			return Err(Bolt11ParseError::InvalidSliceLength(
 				b32.len(),
 				7,
-				"PositiveTimestamp::from_base32()".into(),
+				"timestamp",
 			));
 		}
 		let timestamp: u64 = parse_u64_be(b32)
@@ -475,7 +475,7 @@ impl FromBase32 for Bolt11InvoiceSignature {
 			return Err(Bolt11ParseError::InvalidSliceLength(
 				signature.len(),
 				104,
-				"Bolt11InvoiceSignature::from_base32()".into(),
+				"signature",
 			));
 		}
 		let recoverable_signature_bytes = <[u8; 65]>::from_base32(signature)?;
@@ -745,11 +745,11 @@ impl Display for Bolt11ParseError {
 			Bolt11ParseError::DescriptionDecodeError(ref e) => {
 				write!(f, "Description is not a valid utf-8 string: {}", e)
 			}
-			Bolt11ParseError::InvalidSliceLength(ref len, ref expected, ref function) => {
+			Bolt11ParseError::InvalidSliceLength(ref len, ref expected, ref elemen) => {
 				write!(
 					f,
-					"Slice had length {} instead of {} in function {}",
-					len, expected, function
+					"Slice had length {} instead of {} for element {}",
+					len, expected, elemen
 				)
 			},
 			Bolt11ParseError::BadPrefix => f.write_str("did not begin with 'ln'"),

lightning-invoice/src/lib.rs

@@ -105,8 +105,8 @@ pub enum Bolt11ParseError {
 	InvalidPubKeyHashLength,
 	InvalidScriptHashLength,
 	InvalidRecoveryId,
-	// Invalid length, with actual length, expected length, and function info
-	InvalidSliceLength(usize, usize, String),
+	// Invalid length, with actual length, expected length, and name of the element
+	InvalidSliceLength(usize, usize, &'static str),
 
 	/// Not an error, but used internally to signal that a part of the invoice should be ignored
 	/// according to BOLT11
@@ -312,7 +312,7 @@ impl RawHrp {
 	/// Convert to bech32::Hrp
 	pub fn to_hrp(&self) -> bech32::Hrp {
 		let hrp_str = self.to_string();
-		let s = core::str::from_utf8(&hrp_str.as_bytes()).expect("asserted to be ASCII");
+		let s = core::str::from_utf8(&hrp_str.as_bytes()).expect("HRP bytes should be ASCII");
 		bech32::Hrp::parse_unchecked(s)
 	}
 }

lightning-invoice/src/test_ser_de.rs

@@ -66,7 +66,7 @@ fn array_u8_error_invalid_length() {
 		.err()
 		.unwrap()
 		.to_string(),
-		"Slice had length 4 instead of 5 in function <[u8; N]>::from_base32()"
+		"Slice had length 4 instead of 5 for element <[u8; N]>"
 	);
 }