Add a simple integration test for non-sticky range diff

pkg/integration/tests/diff/diff_non_sticky_range.go

@@ -0,0 +1,45 @@
+package diff
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var DiffNonStickyRange = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "View the combined diff of multiple commits using a range selection",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.EmptyCommit("initial commit")
+		shell.CreateFileAndAdd("file1", "first line\n")
+		shell.Commit("first commit")
+		shell.UpdateFileAndAdd("file1", "first line\nsecond line\n")
+		shell.Commit("second commit")
+		shell.UpdateFileAndAdd("file1", "first line\nsecond line\nthird line\n")
+		shell.Commit("third commit")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("third commit").IsSelected(),
+				Contains("second commit"),
+				Contains("first commit"),
+				Contains("initial commit"),
+			).
+			Press(keys.Universal.RangeSelectDown).
+			Press(keys.Universal.RangeSelectDown).
+			Tap(func() {
+				t.Views().Main().Content(Contains("Showing diff for range ").
+					Contains("+first line\n+second line\n+third line"))
+			}).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			SelectedLine(Contains("file1"))
+
+		t.Views().Main().Content(Contains("+first line\n+second line\n+third line"))
+	},
+})

pkg/integration/tests/test_list.go

@@ -148,6 +148,7 @@ var tests = []*components.IntegrationTest{
 	diff.Diff,
 	diff.DiffAndApplyPatch,
 	diff.DiffCommits,
+	diff.DiffNonStickyRange,
 	diff.IgnoreWhitespace,
 	diff.RenameSimilarityThresholdChange,
 	file.CopyMenu,