basic validation and detection of patterns (#450)

Author: Byron

git-refspec/src/parse.rs

@@ -6,6 +6,10 @@ pub enum Error {
     NegativeWithDestination,
     #[error("Cannot push into an empty destination")]
     PushToEmpty,
+    #[error("glob patterns may only involved a single '*' character, found {pattern:?}")]
+    PatternUnsupported { pattern: bstr::BString },
+    #[error("Both sides of the specification need a pattern, like 'a/*:b/*'")]
+    PatternUnbalanced,
 }
 
 pub(crate) mod function {
@@ -48,17 +52,35 @@ pub(crate) mod function {
                         Operation::Push => return Err(Error::PushToEmpty),
                         Operation::Fetch => (Some(src), None),
                     },
-                    _ => todo!("src or dst handling"),
+                    (Some(src), Some(dst)) => (Some(src), Some(dst)),
                 }
             }
-            None => todo!("no colon"),
+            None => (Some(spec), None),
         };
 
+        let (src, src_had_pattern) = validated(src)?;
+        let (dst, dst_had_pattern) = validated(dst)?;
+        if src_had_pattern != dst_had_pattern {
+            return Err(Error::PatternUnbalanced);
+        }
         Ok(RefSpecRef {
             op: operation,
             mode,
             src,
             dst,
         })
     }
+
+    fn validated(spec: Option<&BStr>) -> Result<(Option<&BStr>, bool), Error> {
+        match spec {
+            Some(spec) => {
+                let glob_count = spec.iter().filter(|b| **b == b'*').take(2).count();
+                if glob_count == 2 {
+                    return Err(Error::PatternUnsupported { pattern: spec.into() });
+                }
+                Ok((Some(spec), glob_count == 1))
+            }
+            None => Ok((None, false)),
+        }
+    }
 }

git-refspec/tests/parse/mod.rs

@@ -15,6 +15,7 @@ fn baseline() {
     while let Some(kind_spec) = lines.next() {
         count += 1;
         let (kind, spec) = kind_spec.split_at(kind_spec.find_byte(b' ').expect("space between kind and spec"));
+        let spec = &spec[1..];
         let err_code: usize = lines
             .next()
             .expect("err code")
@@ -32,7 +33,7 @@ fn baseline() {
             Ok(res) => match (res.is_ok(), err_code == 0) {
                 (true, true) | (false, false) => {}
                 _ => {
-                    eprintln!("{res:?} {err_code}");
+                    eprintln!("{res:?} {err_code} {} {:?}", kind.as_bstr(), spec.as_bstr());
                     mismatch += 1;
                 }
             },
@@ -74,6 +75,27 @@ mod invalid {
         }
     }
 
+    #[test]
+    fn complex_patterns_with_more_than_one_asterisk() {
+        for op in [Operation::Fetch, Operation::Push] {
+            for spec in ["^*/*", "a/*/c/*", "a**:**b", "+:**/"] {
+                assert!(matches!(
+                    try_parse(spec, op).unwrap_err(),
+                    Error::PatternUnsupported { .. }
+                ));
+            }
+        }
+    }
+
+    #[test]
+    fn both_sides_need_pattern_if_one_uses_it() {
+        for op in [Operation::Fetch, Operation::Push] {
+            for spec in ["/*/a", ":a/*", "+:a/*", "a*:b/c", "a:b/*"] {
+                assert!(matches!(try_parse(spec, op).unwrap_err(), Error::PatternUnbalanced));
+            }
+        }
+    }
+
     #[test]
     fn push_to_empty() {
         assert!(matches!(