Add test for moving a patch from a deleted file to a new commit

This currently works, we add it as a regression test to make sure we don't break
it. It is an interesting test because it turns the deletion of the file in the
moved-from commit into a modification.

pkg/integration/tests/patch_building/move_to_new_commit_from_deleted_file.go

@@ -0,0 +1,88 @@
+package patch_building
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var MoveToNewCommitFromDeletedFile = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Move a patch from a file that was deleted in a commit to a new commit",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFileAndAdd("file1", "1st line\n2nd line\n3rd line\n")
+		shell.Commit("first commit")
+		shell.DeleteFileAndAdd("file1")
+		shell.Commit("commit to move from")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("commit to move from").IsSelected(),
+				Contains("first commit"),
+			).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			Lines(
+				Contains("D file1").IsSelected(),
+			).
+			PressEnter()
+
+		t.Views().PatchBuilding().
+			IsFocused().
+			SelectNextItem().
+			PressPrimaryAction()
+
+		t.Views().Information().Content(Contains("Building patch"))
+
+		t.Common().SelectPatchOption(Contains("Move patch into new commit"))
+
+		t.ExpectPopup().CommitMessagePanel().
+			InitialText(Equals("")).
+			Type("new commit").Confirm()
+
+		t.Views().Commits().
+			IsFocused().
+			Lines(
+				Contains("new commit").IsSelected(),
+				Contains("commit to move from"),
+				Contains("first commit"),
+			).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			Lines(
+				Contains("D file1").IsSelected(),
+			).
+			Tap(func() {
+				t.Views().Main().ContainsLines(
+					Equals("-2nd line"),
+				)
+			}).
+			PressEscape()
+
+		t.Views().Commits().
+			IsFocused().
+			NavigateToLine(Contains("commit to move from")).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			Lines(
+				// In the original commit the file is no longer deleted, but modified
+				Contains("M file1").IsSelected(),
+			).
+			Tap(func() {
+				t.Views().Main().ContainsLines(
+					Equals("-1st line"),
+					Equals(" 2nd line"),
+					Equals("-3rd line"),
+				)
+			})
+	},
+})

pkg/integration/tests/test_list.go

@@ -238,6 +238,7 @@ var tests = []*components.IntegrationTest{
 	patch_building.MoveToLaterCommit,
 	patch_building.MoveToLaterCommitPartialHunk,
 	patch_building.MoveToNewCommit,
+	patch_building.MoveToNewCommitFromDeletedFile,
 	patch_building.MoveToNewCommitPartialHunk,
 	patch_building.RemoveFromCommit,
 	patch_building.ResetWithEscape,