add multi-line commit integration test

pkg/integration/tests/commit/commit_multiline.go

@@ -0,0 +1,34 @@
+package commit
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var CommitMultiline = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Commit with a multi-line commit message",
+	ExtraCmdArgs: "",
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFile("myfile", "myfile content")
+	},
+	Run: func(shell *Shell, input *Input, assert *Assert, keys config.KeybindingConfig) {
+		assert.CommitCount(0)
+
+		input.PrimaryAction()
+		input.PressKeys(keys.Files.CommitChanges)
+
+		input.Type("first line")
+		input.PressKeys(keys.Universal.AppendNewline)
+		input.PressKeys(keys.Universal.AppendNewline)
+		input.Type("third line")
+		input.Confirm()
+
+		assert.CommitCount(1)
+		assert.MatchHeadCommitMessage(Equals("first line"))
+
+		input.SwitchToCommitsWindow()
+		assert.MatchMainViewContent(MatchesRegexp("first line\n\\s*\n\\s*third line"))
+	},
+})