feat: support reversing (v) file/hunk/line patch

src/default_config.toml

@@ -119,6 +119,7 @@ root.discard = ["K"]
 root.stage = ["s"]
 root.unstage = ["u"]
 root.apply = ["a"]
+root.reverse = ["v"]
 root.copy_hash = ["y"]
 
 picker.next = ["down", "ctrl+n", "tab"]

src/ops/mod.rs

@@ -24,6 +24,7 @@ pub(crate) mod push;
 pub(crate) mod rebase;
 pub(crate) mod remote;
 pub(crate) mod reset;
+pub(crate) mod reverse;
 pub(crate) mod revert;
 pub(crate) mod show;
 pub(crate) mod show_refs;
@@ -107,6 +108,7 @@ pub(crate) enum Op {
     Show,
     Discard,
     Apply,
+    Reverse,
     CopyHash,
 
     ToggleSection,
@@ -199,6 +201,7 @@ impl Op {
             Op::Stage => Box::new(stage::Stage),
             Op::Unstage => Box::new(unstage::Unstage),
             Op::Apply => Box::new(apply::Apply),
+            Op::Reverse => Box::new(reverse::Reverse),
             Op::CopyHash => Box::new(copy_hash::CopyHash),
 
             Op::AddRemote => Box::new(remote::AddRemote),

src/ops/reverse.rs

@@ -0,0 +1,63 @@
+use super::OpTrait;
+use crate::{
+    Action,
+    app::{App, State},
+    git::diff::{Diff, PatchMode},
+    item_data::ItemData,
+    term::Term,
+};
+use std::{process::Command, rc::Rc};
+
+pub(crate) struct Reverse;
+impl OpTrait for Reverse {
+    fn get_action(&self, target: &ItemData) -> Option<Action> {
+        let action = match target {
+            ItemData::Delta { diff, file_i } => reverse_patch(diff.format_file_patch(*file_i)),
+            ItemData::Hunk {
+                diff,
+                file_i,
+                hunk_i,
+            } => reverse_patch(diff.format_hunk_patch(*file_i, *hunk_i)),
+            ItemData::HunkLine {
+                diff,
+                file_i,
+                hunk_i,
+                line_i,
+                ..
+            } => reverse_line(diff, *file_i, *hunk_i, *line_i),
+            _ => return None,
+        };
+
+        Some(action)
+    }
+
+    fn is_target_op(&self) -> bool {
+        true
+    }
+
+    fn display(&self, _state: &State) -> String {
+        "Reverse".into()
+    }
+}
+
+fn reverse_patch(patch: String) -> Action {
+    let patch = patch.into_bytes();
+
+    Rc::new(move |app: &mut App, term: &mut Term| {
+        let mut cmd = Command::new("git");
+        cmd.args(["apply", "--reverse"]);
+        app.run_cmd(term, &patch, cmd)
+    })
+}
+
+fn reverse_line(diff: &Rc<Diff>, file_i: usize, hunk_i: usize, line_i: usize) -> Action {
+    let patch = diff
+        .format_line_patch(file_i, hunk_i, line_i..(line_i + 1), PatchMode::Reverse)
+        .into_bytes();
+
+    Rc::new(move |app: &mut App, term: &mut Term| {
+        let mut cmd = Command::new("git");
+        cmd.args(["apply", "--reverse", "--recount"]);
+        app.run_cmd(term, &patch, cmd)
+    })
+}

src/tests/mod.rs

@@ -28,6 +28,7 @@ mod quit;
 mod rebase;
 mod remote;
 mod reset;
+mod reverse;
 mod stage;
 mod stash;
 mod unstage;

src/tests/reverse.rs

@@ -0,0 +1,73 @@
+use super::*;
+
+fn snapshot_with_file(snapshot_name: &str, mut ctx: TestContext, filename: &str, keys_input: &str) {
+    let before = fs::read_to_string(ctx.dir.join(filename)).unwrap();
+
+    let mut app = ctx.init_app();
+    ctx.update(&mut app, keys(keys_input));
+
+    let after = fs::read_to_string(ctx.dir.join(filename)).unwrap();
+
+    let mut out = ctx.redact_buffer();
+    out.push_str("\n\n[file before]\n");
+    out.push_str(&before);
+    out.push_str("\n[file after]\n");
+    out.push_str(&after);
+
+    insta::assert_snapshot!(snapshot_name, out);
+}
+
+fn setup(ctx: TestContext) -> TestContext {
+    commit(&ctx.dir, "file-one", "FOO\nBAR\nBAZ\n");
+    fs::write(ctx.dir.join("file-one"), "blahonga\nBAR\nBAZ\n").unwrap();
+    ctx
+}
+
+#[test]
+pub(crate) fn reverse_unstaged_delta() {
+    let ctx = setup(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jjv");
+}
+
+#[test]
+pub(crate) fn reverse_unstaged_hunk() {
+    let ctx = setup(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jj<tab>jv");
+}
+
+#[test]
+pub(crate) fn reverse_unstaged_line() {
+    let ctx = setup(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jj<tab>j<ctrl+j>v");
+}
+
+#[test]
+pub(crate) fn reverse_staged_delta() {
+    let ctx = setup_staged(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jjv");
+}
+
+#[test]
+pub(crate) fn reverse_staged_hunk() {
+    let ctx = setup_staged(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jj<tab>jv");
+}
+
+#[test]
+pub(crate) fn reverse_staged_line() {
+    let ctx = setup_staged(setup_clone!());
+    let snapshot_name = function_name!().rsplit("::").next().unwrap();
+    snapshot_with_file(snapshot_name, ctx, "file-one", "jj<tab>j<ctrl+j>v");
+}
+
+fn setup_staged(ctx: TestContext) -> TestContext {
+    commit(&ctx.dir, "file-one", "FOO\nBAR\nBAZ\n");
+    fs::write(ctx.dir.join("file-one"), "blahonga\nBAR\nBAZ\n").unwrap();
+    run(&ctx.dir, &["git", "add", "file-one"]);
+    ctx
+}

src/tests/snapshots/gitu__tests__reverse__reverse_staged_delta.snap

@@ -0,0 +1,35 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Unstaged changes (1)                                                           |
+▌modified   file-one                                                            |
+▌@@ -1,3 +1,3 @@                                                                |
+▌-blahonga                                                                      |
+▌+FOO                                                                           |
+▌ BAR                                                                           |
+▌ BAZ                                                                           |
+                                                                                |
+ Staged changes (1)                                                             |
+ modified   file-one…                                                           |
+                                                                                |
+ Recent commits                                                                 |
+ 9f4a45e main add file-one                                                      |
+ b66a0bf origin/main add initial-file                                           |
+                                                                                |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse                                                           |
+styles_hash: c3e27c3c64b57280
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+BAR
+BAZ

src/tests/snapshots/gitu__tests__reverse__reverse_staged_hunk.snap

@@ -0,0 +1,35 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Unstaged changes (1)                                                           |
+ modified   file-one                                                            |
+▌@@ -1,3 +1,3 @@                                                                |
+▌-blahonga                                                                      |
+▌+FOO                                                                           |
+▌ BAR                                                                           |
+▌ BAZ                                                                           |
+                                                                                |
+ Staged changes (1)                                                             |
+ modified   file-one                                                            |
+ @@ -1,3 +1,3 @@                                                                |
+ -FOO                                                                           |
+ +blahonga                                                                      |
+  BAR                                                                           |
+  BAZ                                                                           |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse                                                           |
+styles_hash: a5e24bbded675128
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+BAR
+BAZ

src/tests/snapshots/gitu__tests__reverse__reverse_staged_line.snap

@@ -0,0 +1,36 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Unstaged changes (1)                                                           |
+ modified   file-one                                                            |
+ @@ -1,3 +1,4 @@                                                                |
+▌+FOO                                                                           |
+  blahonga                                                                      |
+  BAR                                                                           |
+  BAZ                                                                           |
+                                                                                |
+ Staged changes (1)                                                             |
+ modified   file-one                                                            |
+ @@ -1,3 +1,3 @@                                                                |
+ -FOO                                                                           |
+ +blahonga                                                                      |
+  BAR                                                                           |
+  BAZ                                                                           |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse --recount                                                 |
+styles_hash: d8e20f905aae1d59
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+blahonga
+BAR
+BAZ

src/tests/snapshots/gitu__tests__reverse__reverse_unstaged_delta.snap

@@ -0,0 +1,35 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Recent commits                                                                 |
+▌9f4a45e main add file-one                                                      |
+ b66a0bf origin/main add initial-file                                           |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse                                                           |
+styles_hash: 127ac9ef0aee93e
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+BAR
+BAZ

src/tests/snapshots/gitu__tests__reverse__reverse_unstaged_hunk.snap

@@ -0,0 +1,35 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Recent commits                                                                 |
+ 9f4a45e main add file-one                                                      |
+▌b66a0bf origin/main add initial-file                                           |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse                                                           |
+styles_hash: 80fde90219deddc2
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+BAR
+BAZ

src/tests/snapshots/gitu__tests__reverse__reverse_unstaged_line.snap

@@ -0,0 +1,36 @@
+---
+source: src/tests/reverse.rs
+expression: out
+---
+ On branch main                                                                 |
+ Your branch is ahead of 'origin/main' by 1 commit(s).                          |
+                                                                                |
+ Unstaged changes (1)                                                           |
+ modified   file-one                                                            |
+▌@@ -1,3 +1,4 @@                                                                |
+▌ FOO                                                                           |
+▌+blahonga                                                                      |
+▌ BAR                                                                           |
+▌ BAZ                                                                           |
+                                                                                |
+ Recent commits                                                                 |
+ 9f4a45e main add file-one                                                      |
+ b66a0bf origin/main add initial-file                                           |
+                                                                                |
+                                                                                |
+                                                                                |
+                                                                                |
+────────────────────────────────────────────────────────────────────────────────|
+$ git apply --reverse --recount                                                 |
+styles_hash: 8f5ab6e7fae3f786
+
+[file before]
+blahonga
+BAR
+BAZ
+
+[file after]
+FOO
+blahonga
+BAR
+BAZ