Resolve the prompt just before using it

In case a later command depends on a prompt input from a previous one we
need to evaluate it only after the previous prompt has been confirmed.

pkg/integration/tests/custom_commands/menu_from_commands_output.go

@@ -0,0 +1,69 @@
+package custom_commands
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var MenuFromCommandsOutput = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Using prompt response in menuFromCommand entries",
+	ExtraCmdArgs: "",
+	Skip:         false,
+	SetupRepo: func(shell *Shell) {
+		shell.
+			EmptyCommit("foo").
+			NewBranch("feature/foo").
+			EmptyCommit("bar").
+			NewBranch("feature/bar").
+			EmptyCommit("baz")
+	},
+	SetupConfig: func(cfg *config.AppConfig) {
+		cfg.UserConfig.CustomCommands = []config.CustomCommand{
+			{
+				Key:     "a",
+				Context: "localBranches",
+				Command: "git checkout {{ index .PromptResponses 1 }}",
+				Prompts: []config.CustomCommandPrompt{
+					{
+						Type:         "input",
+						Title:        "Which git command do you want to run?",
+						InitialValue: "branch",
+					},
+					{
+						Type:        "menuFromCommand",
+						Title:       "Branch:",
+						Command:     `git {{ index .PromptResponses 0 }} --format='%(refname:short)'`,
+						Filter:      "(?P<branch>.*)",
+						ValueFormat: `{{ .branch }}`,
+						LabelFormat: `{{ .branch | green }}`,
+					},
+				},
+			},
+		}
+	},
+	Run: func(
+		shell *Shell,
+		input *Input,
+		assert *Assert,
+		keys config.KeybindingConfig,
+	) {
+		assert.WorkingTreeFileCount(0)
+		input.SwitchToBranchesWindow()
+
+		input.PressKeys("a")
+
+		assert.InPrompt()
+		assert.MatchCurrentViewTitle(Equals("Which git command do you want to run?"))
+		assert.MatchSelectedLine(Equals("branch"))
+		input.Confirm()
+
+		assert.InMenu()
+		assert.MatchCurrentViewTitle(Equals("Branch:"))
+		input.NextItem()
+		input.NextItem()
+		assert.MatchSelectedLine(Equals("master"))
+		input.Confirm()
+
+		assert.CurrentBranchName("master")
+	},
+})