feat: optimize IdentifierError variants

.changelog/unreleased/breaking-changes/978-identifier-error.md

@@ -0,0 +1,2 @@
+- Optimize `IdentifierError` variants and make them mutually exclusive.
+  ([\#978](https://github.com/cosmos/ibc-rs/issues/978))

ibc-core/ics24-host/types/src/error.rs

@@ -4,15 +4,8 @@ use ibc_primitives::prelude::*;
 #[cfg_attr(feature = "serde", derive(serde::Serialize))]
 #[derive(Debug, Display)]
 pub enum IdentifierError {
-    /// identifier `{id}` cannot contain separator '/'
-    ContainSeparator { id: String },
-    /// identifier `{id}` has invalid length `{length}` must be between `{min}`-`{max}` characters
-    InvalidLength {
-        id: String,
-        length: u64,
-        min: u64,
-        max: u64,
-    },
+    /// identifier `{id}` has invalid length; must be between `{min}` and `{max}` characters
+    InvalidLength { id: String, min: u64, max: u64 },
     /// identifier `{id}` must only contain alphanumeric characters or `.`, `_`, `+`, `-`, `#`, - `[`, `]`, `<`, `>`
     InvalidCharacter { id: String },
     /// identifier prefix `{prefix}` is invalid
@@ -23,8 +16,6 @@ pub enum IdentifierError {
     RevisionNumberOverflow,
     /// String `{value}` cannot be converted to packet sequence, error: `{reason}`
     InvalidStringAsSequence { value: String, reason: String },
-    /// identifier cannot be empty
-    Empty,
 }
 
 #[cfg(feature = "std")]

ibc-core/ics24-host/types/src/validate.rs

@@ -2,19 +2,12 @@ use ibc_primitives::prelude::*;
 
 use crate::error::IdentifierError as Error;
 
-/// Path separator (ie. forward slash '/')
-const PATH_SEPARATOR: char = '/';
 const VALID_SPECIAL_CHARS: &str = "._+-#[]<>";
 
 /// Checks if the identifier only contains valid characters as specified in the
 /// [`ICS-24`](https://github.com/cosmos/ibc/tree/main/spec/core/ics-024-host-requirements#paths-identifiers-separators)]
 /// spec.
 pub fn validate_identifier_chars(id: &str) -> Result<(), Error> {
-    // Check identifier does not contain path separators
-    if id.contains(PATH_SEPARATOR) {
-        return Err(Error::ContainSeparator { id: id.into() });
-    }
-
     // Check that the identifier comprises only valid characters:
     // - Alphanumeric
     // - `.`, `_`, `+`, `-`, `#`
@@ -42,7 +35,6 @@ pub fn validate_identifier_length(id: &str, min: u64, max: u64) -> Result<(), Er
     } else {
         Err(Error::InvalidLength {
             id: id.into(),
-            length,
             min,
             max,
         })