fix: channel name display (#531)

channel wasn't displayed if there was no `name`. 

Using `name()` now and formatting the `:` correctly

Useful to simplify the generation of pixi.toml from environment yaml

Author: ruben-arts

crates/rattler_conda_types/src/match_spec/mod.rs

@@ -146,27 +146,25 @@ pub struct MatchSpec {
 impl Display for MatchSpec {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         if let Some(channel) = &self.channel {
-            if let Some(name) = &channel.name {
-                // TODO: namespace
-                write!(f, "{name}")?;
+            let name = channel.name();
+            write!(f, "{name}")?;
+
+            if let Some(subdir) = &self.subdir {
+                write!(f, "/{subdir}")?;
             }
         }
 
-        if let Some(subdir) = &self.subdir {
-            write!(f, "/{subdir}")?;
+        if let Some(namespace) = &self.namespace {
+            write!(f, ":{namespace}:")?;
+        } else if self.channel.is_some() || self.subdir.is_some() {
+            write!(f, "::")?;
         }
 
         match &self.name {
             Some(name) => write!(f, "{}", name.as_normalized())?,
             None => write!(f, "*")?,
         }
 
-        if let Some(namespace) = &self.namespace {
-            write!(f, ":{namespace}:")?;
-        } else if self.channel.is_some() || self.subdir.is_some() {
-            write!(f, "::")?;
-        }
-
         if let Some(version) = &self.version {
             write!(f, " {version}")?;
         }
@@ -407,11 +405,12 @@ mod tests {
     use rattler_digest::{parse_digest_from_hex, Md5, Sha256};
 
     use crate::{MatchSpec, NamelessMatchSpec, PackageName, PackageRecord, Version};
+    use insta::assert_snapshot;
     use std::hash::{Hash, Hasher};
 
     #[test]
     fn test_matchspec_format_eq() {
-        let spec = MatchSpec::from_str("mamba[version==1.0, sha256=aaac4bc9c6916ecc0e33137431645b029ade22190c7144eead61446dcbcc6f97, md5=dede6252c964db3f3e41c7d30d07f6bf]").unwrap();
+        let spec = MatchSpec::from_str("conda-forge::mamba[version==1.0, sha256=aaac4bc9c6916ecc0e33137431645b029ade22190c7144eead61446dcbcc6f97, md5=dede6252c964db3f3e41c7d30d07f6bf]").unwrap();
         let spec_as_string = spec.to_string();
         let rebuild_spec = MatchSpec::from_str(&spec_as_string).unwrap();
 
@@ -495,4 +494,21 @@ mod tests {
         let spec = MatchSpec::from_str("mamba[version==1.0, md5=dede6252c964db3f3e41c7d30d07f6bf, sha256=aaac4bc9c6916ecc0e33137431645b029ade22190c7144eead61446dcbcc6f97]").unwrap();
         assert!(!spec.matches(&record));
     }
+
+    #[test]
+    fn test_serialize_matchspec() {
+        let specs = ["mamba 1.0 py37_0",
+            "conda-forge::pytest[version=1.0, sha256=aaac4bc9c6916ecc0e33137431645b029ade22190c7144eead61446dcbcc6f97, md5=dede6252c964db3f3e41c7d30d07f6bf]",
+            "conda-forge/linux-64::pytest",
+            "conda-forge/linux-64::pytest[version=1.0]",
+            "conda-forge/linux-64::pytest[version=1.0, build=py37_0]",
+            "conda-forge/linux-64::pytest 1.2.3"];
+
+        assert_snapshot!(specs
+            .into_iter()
+            .map(|s| MatchSpec::from_str(s).unwrap())
+            .map(|s| s.to_string())
+            .collect::<Vec<String>>()
+            .join("\n"));
+    }
 }

crates/rattler_conda_types/src/match_spec/snapshots/rattler_conda_types__match_spec__tests__serialize_matchspec.snap

@@ -0,0 +1,10 @@
+---
+source: crates/rattler_conda_types/src/match_spec/mod.rs
+expression: "specs.into_iter().map(|s|\n                    MatchSpec::from_str(s).unwrap()).map(|s|\n                s.to_string()).collect::<Vec<String>>().join(\"\\n\")"
+---
+mamba ==1.0 py37_0
+conda-forge::pytest ==1.0[md5=dede6252c964db3f3e41c7d30d07f6bf, sha256=aaac4bc9c6916ecc0e33137431645b029ade22190c7144eead61446dcbcc6f97]
+conda-forge/linux-64::pytest
+conda-forge/linux-64::pytest ==1.0
+conda-forge/linux-64::pytest ==1.0 py37_0
+conda-forge/linux-64::pytest ==1.2.3