fix(constraint): handle single pipe OR separator in version constraints

Composer uses `|` (single pipe) as the standard OR separator, but
split_or() only recognized `||` (double pipe). This caused disjunctive
constraints like `^6.0|^7.0|^8.0` to be parsed as only `^6.0`,
breaking dependency resolution for packages like laravel/tinker.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/crates/mozart-constraint/src/lib.rs b/crates/mozart-constraint/src/lib.rs
index e41818c..7c417ec 100644
--- a/crates/mozart-constraint/src/lib.rs
+++ b/crates/mozart-constraint/src/lib.rs
@@ -365,23 +365,28 @@ impl VersionConstraint {
     }
 }
 
-/// Split on `||` (pipe-OR), but not inside version strings.
+/// Split on `|` or `||` (pipe-OR). Composer accepts both forms.
 fn split_or(s: &str) -> Vec<&str> {
     let mut parts = Vec::new();
     let mut start = 0;
     let bytes = s.as_bytes();
     let mut i = 0;
     while i < bytes.len() {
-        if i + 1 < bytes.len() && bytes[i] == b'|' && bytes[i + 1] == b'|' {
+        if bytes[i] == b'|' {
             parts.push(s[start..i].trim());
-            i += 2;
+            i += 1;
+            // Skip second pipe if `||`
+            if i < bytes.len() && bytes[i] == b'|' {
+                i += 1;
+            }
             start = i;
         } else {
             i += 1;
         }
     }
     parts.push(s[start..].trim());
-    parts
+    // Filter out empty parts (e.g. from leading/trailing pipes)
+    parts.into_iter().filter(|p| !p.is_empty()).collect()
 }
 
 /// Parse an AND group (space or comma separated constraints).
@@ -1605,6 +1610,16 @@ mod tests {
     }
 
     #[test]
+    fn test_single_pipe_or() {
+        // Single pipe `|` is the standard Composer OR separator
+        assert!(satisfies("^6.0|^7.0|^8.0|^9.0|^10.0|^11.0", "6.0.0"));
+        assert!(satisfies("^6.0|^7.0|^8.0|^9.0|^10.0|^11.0", "9.0.0"));
+        assert!(satisfies("^6.0|^7.0|^8.0|^9.0|^10.0|^11.0", "11.5.0"));
+        assert!(!satisfies("^6.0|^7.0|^8.0|^9.0|^10.0|^11.0", "5.9.9"));
+        assert!(!satisfies("^6.0|^7.0|^8.0|^9.0|^10.0|^11.0", "12.0.0"));
+    }
+
+    #[test]
     fn test_combined_real_world_symfony_pattern() {
         // ">=5.4 <7.0" — typical Symfony range
         assert!(satisfies(">=5.4 <7.0", "5.4.0"));