fix(service): support host IP in brackets for ports short syntax

Extracted bracket striping logic from `extra_hosts` deserialization into
its own function: `compose_spec::service::strip_brackets()`.

Used `strip_brackets()` for host IP parsing in
`impl FromStr for compose_spec::service::ports::ShortPort`.

Added test
`compose_spec::service::ports::tests::short_port::host_ip_brackets()`
to ensure the fix is working as expected.

Fixes: #24

Cargo.toml

@@ -226,7 +226,7 @@ sort_commits = "oldest"
 
 [package]
 name = "compose_spec"
-version = "0.2.1-alpha.3"
+version = "0.2.1-alpha.4"
 authors.workspace = true
 edition.workspace = true
 license.workspace = true

src/service.rs

@@ -1078,18 +1078,25 @@ where
                 de::Error::custom("extra host value must be a string representing an IP address")
             })?;
 
-            // Remove brackets possibly surrounding IP address, e.g. `[::1]`
-            let value = value.strip_prefix('[').unwrap_or(value);
-            let value = value.strip_suffix(']').unwrap_or(value);
-
             Ok((
                 Hostname::new(key).map_err(de::Error::custom)?,
-                value.parse().map_err(de::Error::custom)?,
+                strip_brackets(value).parse().map_err(de::Error::custom)?,
             ))
         })
         .collect()
 }
 
+/// Remove surrounding square brackets from a string slice.
+///
+/// If the brackets are not in a pair, then the string is returned unchanged.
+///
+/// For example, an IPv6 address may be in brackets, `[::1]` to `::1`.
+fn strip_brackets(s: &str) -> &str {
+    s.strip_prefix('[')
+        .and_then(|s| s.strip_suffix(']'))
+        .unwrap_or(s)
+}
+
 /// IPC isolation mode for a [`Service`] container.
 ///
 /// Available values are platform specific.

src/service/ports.rs

@@ -20,6 +20,8 @@ use thiserror::Error;
 
 use crate::{impl_from_str, serde::FromStrOrU16Visitor, Extensions, ShortOrLong};
 
+use super::strip_brackets;
+
 /// [`Service`](super::Service) container ports to publish to the host.
 ///
 /// [compose-spec](https://github.com/compose-spec/compose-spec/blob/master/05-services.md#ports)
@@ -308,7 +310,7 @@ impl FromStr for ShortPort {
             })
             .map(|(host_ip, rest)| {
                 s = rest;
-                host_ip
+                strip_brackets(host_ip)
                     .parse()
                     .map_err(|source| ParseShortPortError::IpAddr {
                         source,
@@ -973,6 +975,8 @@ pub(super) mod tests {
     use super::*;
 
     mod short_port {
+        use std::net::Ipv6Addr;
+
         use super::*;
 
         proptest! {
@@ -986,6 +990,22 @@ pub(super) mod tests {
                 prop_assert_eq!(&port, &port.to_string().parse()?);
             }
         }
+
+        #[test]
+        fn host_ip_brackets() -> Result<(), ParseShortPortError> {
+            let port = ShortPort {
+                host_ip: Some(IpAddr::V6(Ipv6Addr::LOCALHOST)),
+                ranges: ShortRanges {
+                    host: Some(80.into()),
+                    container: 80.into(),
+                },
+                protocol: None,
+            };
+            assert_eq!("[::1]:80:80".parse::<ShortPort>()?, port);
+            assert_eq!("::1:80:80".parse::<ShortPort>()?, port);
+
+            Ok(())
+        }
     }
 
     mod range {