show diff of new untracked files

README.md

@@ -38,7 +38,6 @@ gitui
 * [x] commit
 * [x] [input polling in thread](assets/perf_compare.jpg)
 * [x] async git API for fluid control
-* [ ] show content of new unstaged files 
 * [ ] discard untracked files (remove)
 * [ ] (un)staging selected hunks
 

asyncgit/src/sync/diff.rs

@@ -1,6 +1,9 @@
 use super::utils;
-use git2::{DiffFormat, DiffOptions};
+use git2::{
+    Delta, DiffDelta, DiffFormat, DiffHunk, DiffOptions, Patch,
+};
 use scopetime::scope_time;
+use std::fs;
 
 ///
 #[derive(Copy, Clone, PartialEq)]
@@ -38,7 +41,7 @@ pub fn get_diff(p: String, stage: bool) -> Diff {
     opt.pathspec(p);
 
     let diff = if !stage {
-        // diff against stage
+        opt.include_untracked(true);
         repo.diff_index_to_workdir(None, Some(&mut opt)).unwrap()
     } else {
         // diff against head
@@ -56,7 +59,7 @@ pub fn get_diff(p: String, stage: bool) -> Diff {
 
     let mut res = Vec::new();
 
-    diff.print(DiffFormat::Patch, |_delta, _hunk, line| {
+    let mut put = |line: git2::DiffLine| {
         let origin = line.origin();
 
         if origin != 'F' {
@@ -82,9 +85,51 @@ pub fn get_diff(p: String, stage: bool) -> Diff {
 
             res.push(diff_line);
         }
-        true
-    })
-    .unwrap();
+    };
+
+    let new_file_diff = if diff.deltas().len() == 1 {
+        let delta: DiffDelta = diff.deltas().next().unwrap();
+
+        if delta.status() == Delta::Untracked {
+            let newfile_path = delta.new_file().path().unwrap();
+
+            let newfile_content =
+                fs::read_to_string(newfile_path).unwrap();
+
+            let mut patch = Patch::from_buffers(
+                &[],
+                None,
+                newfile_content.as_bytes(),
+                Some(newfile_path),
+                Some(&mut opt),
+            )
+            .unwrap();
+
+            patch
+                .print(&mut |_delta, _hunk, line: git2::DiffLine| {
+                    put(line);
+                    true
+                })
+                .unwrap();
+
+            true
+        } else {
+            false
+        }
+    } else {
+        false
+    };
+
+    if !new_file_diff {
+        diff.print(
+            DiffFormat::Patch,
+            |_, _, line: git2::DiffLine| {
+                put(line);
+                true
+            },
+        )
+        .unwrap();
+    }
 
     Diff(res)
 }