Add integration test that accesses commit properties in a custom command

Useful as a regression test to check that the following commit doesn't break it.

pkg/integration/tests/custom_commands/access_commit_properties.go

@@ -0,0 +1,37 @@
+package custom_commands
+
+import (
+	"fmt"
+
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var AccessCommitProperties = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Run a command that accesses properties of a commit",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupRepo: func(shell *Shell) {
+		shell.EmptyCommit("my change")
+	},
+	SetupConfig: func(cfg *config.AppConfig) {
+		cfg.UserConfig.CustomCommands = []config.CustomCommand{
+			{
+				Key:     "X",
+				Context: "commits",
+				Command: "printf '%s\n%s' '{{ .SelectedLocalCommit.Name }}' '{{ .SelectedLocalCommit.Hash }}' > file.txt",
+			},
+		}
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("my change").IsSelected(),
+			).
+			Press("X")
+
+		hash := t.Git().GetCommitHash("HEAD")
+		t.FileSystem().FileContent("file.txt", Equals(fmt.Sprintf("my change\n%s", hash)))
+	},
+})