From 9448fe665a4bebe801a8e247c5ddb7a3e4f57223 Mon Sep 17 00:00:00 2001
From: Martin von Zweigbergk <martinvonz@google.com>
Date: Sat, 26 Jun 2021 10:01:29 -0700
Subject: [PATCH] files: use diff::DiffHunk in DiffLine definition

The new `diff::DiffHunk` type is very similar but more generic. We
don't need the generality here. I just don't two very similar types
with the same name.
---
 lib/src/files.rs | 21 +++++++++------------
 src/commands.rs  | 25 +++++++++++++++----------
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/lib/src/files.rs b/lib/src/files.rs
index 9245921f9..904562a16 100644
--- a/lib/src/files.rs
+++ b/lib/src/files.rs
@@ -17,14 +17,7 @@ use std::fmt::{Debug, Error, Formatter};
 use std::ops::Range;
 
 use crate::diff;
-use crate::diff::SliceDiff;
-
-#[derive(PartialEq, Eq, Clone, Debug)]
-pub enum DiffHunk<'a> {
-    Unmodified(&'a [u8]),
-    Added(&'a [u8]),
-    Removed(&'a [u8]),
-}
+use crate::diff::{DiffHunk, SliceDiff};
 
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub struct DiffLine<'a> {
@@ -45,7 +38,7 @@ impl DiffLine<'_> {
     pub fn is_unmodified(&self) -> bool {
         self.hunks
             .iter()
-            .all(|hunk| matches!(hunk, DiffHunk::Unmodified(_)))
+            .all(|hunk| matches!(hunk, DiffHunk::Matching(_)))
     }
 }
 
@@ -94,7 +87,7 @@ impl<'a> Iterator for DiffLineIterator<'a> {
                     for line in lines {
                         self.current_line.has_left_content = true;
                         self.current_line.has_right_content = true;
-                        self.current_line.hunks.push(DiffHunk::Unmodified(line));
+                        self.current_line.hunks.push(DiffHunk::Matching(line));
                         if line.ends_with(b"\n") {
                             self.queued_lines.push_back(self.current_line.clone());
                             self.current_line.left_line_number += 1;
@@ -107,7 +100,9 @@ impl<'a> Iterator for DiffLineIterator<'a> {
                     let left_lines = left.split_inclusive(|b| *b == b'\n');
                     for left_line in left_lines {
                         self.current_line.has_left_content = true;
-                        self.current_line.hunks.push(DiffHunk::Removed(left_line));
+                        self.current_line
+                            .hunks
+                            .push(DiffHunk::Different(vec![left_line, b""]));
                         if left_line.ends_with(b"\n") {
                             self.queued_lines.push_back(self.current_line.clone());
                             self.current_line.left_line_number += 1;
@@ -117,7 +112,9 @@ impl<'a> Iterator for DiffLineIterator<'a> {
                     let right_lines = right.split_inclusive(|b| *b == b'\n');
                     for right_line in right_lines {
                         self.current_line.has_right_content = true;
-                        self.current_line.hunks.push(DiffHunk::Added(right_line));
+                        self.current_line
+                            .hunks
+                            .push(DiffHunk::Different(vec![b"", right_line]));
                         if right_line.ends_with(b"\n") {
                             self.queued_lines.push_back(self.current_line.clone());
                             self.current_line.right_line_number += 1;
diff --git a/src/commands.rs b/src/commands.rs
index 5b5110253..25af6c536 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -33,6 +33,7 @@ use itertools::Itertools;
 use jujutsu_lib::commit::Commit;
 use jujutsu_lib::commit_builder::CommitBuilder;
 use jujutsu_lib::dag_walk::topo_order_reverse;
+use jujutsu_lib::diff::DiffHunk;
 use jujutsu_lib::evolution::{
     DivergenceResolution, DivergenceResolver, OrphanResolution, OrphanResolver,
 };
@@ -1037,18 +1038,22 @@ fn print_diff_line(formatter: &mut dyn Formatter, diff_line: &DiffLine) -> io::R
     }
     for hunk in &diff_line.hunks {
         match hunk {
-            files::DiffHunk::Unmodified(data) => {
+            DiffHunk::Matching(data) => {
                 formatter.write_bytes(data)?;
             }
-            files::DiffHunk::Removed(data) => {
-                formatter.add_label(String::from("left"))?;
-                formatter.write_bytes(data)?;
-                formatter.remove_label()?;
-            }
-            files::DiffHunk::Added(data) => {
-                formatter.add_label(String::from("right"))?;
-                formatter.write_bytes(data)?;
-                formatter.remove_label()?;
+            DiffHunk::Different(data) => {
+                let before = data[0];
+                let after = data[1];
+                if !before.is_empty() {
+                    formatter.add_label(String::from("left"))?;
+                    formatter.write_bytes(before)?;
+                    formatter.remove_label()?;
+                }
+                if !after.is_empty() {
+                    formatter.add_label(String::from("right"))?;
+                    formatter.write_bytes(after)?;
+                    formatter.remove_label()?;
+                }
             }
         }
     }