write_since(): Take an arbitrary branch as input

Allow the branch to be parameterised instead of forcing the base to be
the local "master" branch.

Added the `Todos` struct to store a `Repository` reference, since we
need this for both the base ref and the diff.

Decided to take a `Tree` instead of a `Branch` because we might want to
compare against an arbitrary ref and allow users to specify that ref on
the command line.

2 files changed, 55 insertions, 45 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 1b9689a..bc3c9b0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,50 +2,55 @@
 
 use std::io::Write;
 
-use git2::Repository;
-
-
-pub fn write_since<W: Write>(write_to: &mut W) {
-    let repo = Repository::open(".").unwrap();
-
-    // let head = repo.head().unwrap().target().unwrap();
-    let master = repo.find_branch("master", git2::BranchType::Local).unwrap();
-    // let merge_base = repo.merge_base(head, master.get().target().unwrap()).unwrap();
-
-    let tree = master.get().peel_to_tree().unwrap();
-    let diff = repo.diff_tree_to_workdir(Some(&tree), None).unwrap();
-
-    diff.foreach(
-        &mut |_file, _progress| {
-            true
-        },
-        None,
-        None,
-        Some(
-            &mut |delta, hunk, line| {
-                // println!(
-                //     "d: {:?}, h: {:?}, l: {:?}",
-                //     delta,
-                //     hunk,
-                //     std::str::from_utf8(line.content()).unwrap(),
-                // );
-
-                if let Some(line_number) = line.new_lineno() {
-                    let l = std::str::from_utf8(line.content()).unwrap();
-
-                    if l.contains("TODO") {
-                        write!(
-                            write_to,
-                            "{}:{}:{}",
-                            delta.new_file().path().unwrap().display(),
-                            line_number,
-                            l,
-                        ).unwrap();
+use git2::{Repository, Tree};
+
+
+pub struct Todos<'a> {
+    pub repo: &'a Repository,
+}
+
+impl Todos<'_> {
+    pub fn write_since<W: Write>(&self, tree: Tree<'_>, write_to: &mut W) {
+        let diff = self.repo.diff_tree_to_workdir(Some(&tree), None).unwrap();
+
+        diff.foreach(
+            &mut |_file, _progress| {
+                true
+            },
+            None,
+            None,
+            Some(
+                &mut |delta, hunk, line| {
+                    // println!(
+                    //     "d: {:?}, h: {:?}, l: {:?}",
+                    //     delta,
+                    //     hunk,
+                    //     std::str::from_utf8(line.content()).unwrap(),
+                    // );
+
+                    if let Some(line_number) = line.new_lineno() {
+                        let l = std::str::from_utf8(line.content()).unwrap();
+
+                        if l.contains("TODO") {
+                            write!(
+                                write_to,
+                                "{}:{}:{}",
+                                delta.new_file().path().unwrap().display(),
+                                line_number,
+                                l,
+                            ).unwrap();
+                        }
                     }
+
+                    true
                 }
+            ),
+        ).unwrap();
+    }
 
-                true
-            }
-        ),
-    ).unwrap();
+    pub fn master_tree(&self) -> Tree<'_> {
+        let master = self.repo.find_branch("master", git2::BranchType::Local).unwrap();
+
+        master.get().peel_to_tree().unwrap()
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index 60f12d8..48e8f5d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,13 @@
 #![warn(rust_2018_idioms)]
 
-use git_todo::write_since;
+use git2::Repository;
+
+use git_todo::Todos;
 
 
 fn main() {
-    write_since(&mut std::io::stdout());
+    let repo = Repository::open(".").unwrap();
+
+    let todos = Todos { repo: &repo };
+    todos.write_since(todos.master_tree(), &mut std::io::stdout());
 }