resolve git, better erroring

Author: gnunicorn

src/cli.rs

@@ -397,7 +397,7 @@ fn make_pkg_predicate(ws: &Workspace<'_>, args: PackageSelectOptions) -> Result<
 
     }
 
-    let changed = util::changed_packages(ws, &changed_since);
+    let changed = util::changed_packages(ws, &changed_since)?;
     if changed.len() == 0 {
         return Err("No changes detected".into())
     };

src/util.rs

@@ -3,7 +3,7 @@ use cargo::{
     util::interning::InternedString,
     sources::PathSource,
 };
-use log::warn;
+use log::{warn, trace};
 use std::{
     collections::{HashSet, HashMap},
     error::Error, fs,
@@ -60,23 +60,29 @@ where
     (graph, map)
 }
 
-pub fn changed_packages<'a>(ws: &'a Workspace, reference: &str) -> HashSet<Package> {
+pub fn changed_packages<'a>(ws: &'a Workspace, reference: &str) -> Result<HashSet<Package>, String> {
+
+    ws.config()
+        .shell()
+        .status("Calculating", format!("git diff since {:}", reference))
+        .expect("Writing to Shell doesn't fail");
+
     let path = ws.root();
-    println!("{:?}", path);
-    let repo = Repository::open(&path).expect("Workspace isn't a git repo");
+    let repo = Repository::open(&path)
+        .map_err(|e| format!("Workspace isn't a git repo: {:?}", e))?;
     let current_head = repo.head()
         .and_then(|b| b.peel_to_commit())
         .and_then(|c| c.tree())
-        .expect("Could not determine current git HEAD");
+        .map_err(|e| format!("Could not determine current git HEAD: {:?}", e))?;
     let main = repo
-        .find_reference(reference)
+        .resolve_reference_from_short_name(reference)
         .and_then(|d| d.peel_to_commit())
         .and_then(|c| c.tree())
-        .expect("Reference not found in git repository");
+        .map_err(|e| format!("Reference not found in git repository: {:?}", e))?;
 
     let diff = repo
         .diff_tree_to_tree(Some(&current_head), Some(&main), None)
-        .expect("Diffing failed");
+        .map_err(|e| format!("Diffing failed: {:?}", e))?;
 
     let files = diff
         .deltas()
@@ -85,6 +91,8 @@ pub fn changed_packages<'a>(ws: &'a Workspace, reference: &str) -> HashSet<Packa
         .map(|l| path.join(l))
         .collect::<Vec<_>>();
 
+    trace!("Files changed since: {:#?}", files);
+
     let mut packages = HashSet::new();
 
     for m in members_deep(ws) {
@@ -97,7 +105,7 @@ pub fn changed_packages<'a>(ws: &'a Workspace, reference: &str) -> HashSet<Packa
         }
     }
 
-    packages
+    Ok(packages)
 }
 
 // Find all members of the workspace, into the total depth