feat: dynamic banner resizing via bubbletea view

cmd/shell/banner.go

@@ -0,0 +1,64 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shell
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/charmbracelet/lipgloss"
+)
+
+// bannerView returns the styled banner string at the given width.
+func bannerView(width int, version string) string {
+	line := lipgloss.NewStyle().Foreground(colorPool).Render(strings.Repeat("─", width))
+	face := renderSlackbot()
+	title := lipgloss.NewStyle().Bold(true).Foreground(colorAubergine).Render("Slack CLI Shell")
+	ver := lipgloss.NewStyle().Foreground(colorPool).Render("  " + version)
+	hint := lipgloss.NewStyle().Foreground(colorGray).Italic(true).Render("Type 'help' for commands, 'exit' to quit")
+	info := title + ver + "\n" + hint
+	body := lipgloss.JoinHorizontal(lipgloss.Center, face, "   "+info)
+	return line + "\n" + body + "\n" + line
+}
+
+// Slack brand colors (reused from internal/style/charm_theme.go)
+var (
+	colorAubergine = lipgloss.Color("#7C2852")
+	colorPool      = lipgloss.Color("#78d7dd")
+	colorGray      = lipgloss.Color("#5e5d60")
+	colorGreen     = lipgloss.Color("#2eb67d")
+	colorBlue      = lipgloss.Color("#36c5f0")
+)
+
+// renderSlackbot returns a multi-colored ASCII slackbot face.
+func renderSlackbot() string {
+	box := lipgloss.NewStyle().Foreground(colorPool)
+	eye := lipgloss.NewStyle().Foreground(colorBlue).Bold(true)
+	smile := lipgloss.NewStyle().Foreground(colorGreen)
+	lines := []string{
+		box.Render("  ╭───────╮"),
+		box.Render("  │ ") + eye.Render("●") + box.Render("   ") + eye.Render("●") + box.Render(" │"),
+		box.Render("  │   ") + smile.Render("◡") + box.Render("   │"),
+		box.Render("  ╰───────╯"),
+	}
+	return strings.Join(lines, "\n")
+}
+
+// renderGoodbye writes the goodbye message to the writer.
+func renderGoodbye(w io.Writer) {
+	msg := lipgloss.NewStyle().Foreground(colorGreen).Render("Goodbye!")
+	fmt.Fprintf(w, "%s\n", msg)
+}

cmd/shell/input.go

@@ -0,0 +1,137 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shell
+
+import (
+	"strings"
+
+	"github.com/charmbracelet/bubbles/textinput"
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+	"github.com/slackapi/slack-cli/internal/shared"
+)
+
+// inputModel wraps a bubbles textinput with shell history navigation.
+type inputModel struct {
+	textInput     textinput.Model
+	history       []string
+	histIndex     int    // len(history) = "new line" position
+	saved         string // user's in-progress text before navigating history
+	done          bool
+	value         string
+	width         int
+	bannerVersion string // non-empty = show banner above input
+}
+
+// readLine runs a short-lived bubbletea program to collect one line of input.
+func readLine(clients *shared.ClientFactory, history []string, bannerVersion string) (string, error) {
+	m := newInputModel(history, bannerVersion)
+	p := tea.NewProgram(m,
+		tea.WithInput(clients.IO.ReadIn()),
+		tea.WithOutput(clients.IO.WriteOut()),
+	)
+	result, err := p.Run()
+	if err != nil {
+		return "", err
+	}
+	final := result.(inputModel)
+	return final.value, nil
+}
+
+func newInputModel(history []string, bannerVersion string) inputModel {
+	ti := textinput.New()
+	ti.Prompt = "❯ "
+	ti.PromptStyle = lipgloss.NewStyle().Bold(true).Foreground(colorBlue)
+	ti.Cursor.Style = lipgloss.NewStyle().Foreground(lipgloss.Color("#e8a400"))
+	ti.Focus()
+
+	// Disable built-in suggestion navigation (we use Up/Down for history)
+	ti.KeyMap.NextSuggestion.SetEnabled(false)
+	ti.KeyMap.PrevSuggestion.SetEnabled(false)
+
+	return inputModel{
+		textInput:     ti,
+		history:       history,
+		histIndex:     len(history),
+		bannerVersion: bannerVersion,
+	}
+}
+
+func (m inputModel) Init() tea.Cmd {
+	return textinput.Blink
+}
+
+func (m inputModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.WindowSizeMsg:
+		m.width = msg.Width
+		return m, tea.ClearScreen
+	case tea.KeyMsg:
+		switch msg.Type {
+		case tea.KeyEnter:
+			m.done = true
+			m.value = m.textInput.Value()
+			return m, tea.Quit
+		case tea.KeyCtrlC:
+			m.done = true
+			m.value = "exit"
+			return m, tea.Quit
+		case tea.KeyUp:
+			if m.histIndex > 0 {
+				// Save current text on first Up press
+				if m.histIndex == len(m.history) {
+					m.saved = m.textInput.Value()
+				}
+				m.histIndex--
+				m.textInput.SetValue(m.history[m.histIndex])
+				m.textInput.CursorEnd()
+			}
+			return m, nil
+		case tea.KeyDown:
+			if m.histIndex < len(m.history) {
+				m.histIndex++
+				if m.histIndex == len(m.history) {
+					m.textInput.SetValue(m.saved)
+				} else {
+					m.textInput.SetValue(m.history[m.histIndex])
+				}
+				m.textInput.CursorEnd()
+			}
+			return m, nil
+		}
+	}
+
+	var cmd tea.Cmd
+	m.textInput, cmd = m.textInput.Update(msg)
+	return m, cmd
+}
+
+func (m inputModel) View() string {
+	if m.done {
+		return ""
+	}
+	w := m.width
+	if w <= 0 {
+		w = 80
+	}
+	line := lipgloss.NewStyle().Foreground(colorPool).Render(strings.Repeat("─", w))
+	content := " " + m.textInput.View()
+	input := line + "\n" + content + "\n" + line
+
+	if m.bannerVersion != "" {
+		return bannerView(w, m.bannerVersion) + "\n" + input
+	}
+	return input
+}

cmd/shell/input_test.go

@@ -0,0 +1,194 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shell
+
+import (
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/x/ansi"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInputModel(t *testing.T) {
+	tests := map[string]struct {
+		setup    func() inputModel
+		actions  func(inputModel) inputModel
+		assertFn func(t *testing.T, m inputModel)
+	}{
+		"enter submits text": {
+			setup: func() inputModel {
+				return newInputModel(nil, "")
+			},
+			actions: func(m inputModel) inputModel {
+				for _, r := range "deploy" {
+					updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{r}})
+					m = updated.(inputModel)
+				}
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.True(t, m.done)
+				assert.Equal(t, "deploy", m.value)
+			},
+		},
+		"ctrl+c returns exit": {
+			setup: func() inputModel {
+				return newInputModel(nil, "")
+			},
+			actions: func(m inputModel) inputModel {
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyCtrlC})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.True(t, m.done)
+				assert.Equal(t, "exit", m.value)
+			},
+		},
+		"up arrow recalls history": {
+			setup: func() inputModel {
+				return newInputModel([]string{"deploy", "run"}, "")
+			},
+			actions: func(m inputModel) inputModel {
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.Equal(t, "run", m.textInput.Value())
+				assert.Equal(t, 1, m.histIndex)
+			},
+		},
+		"up arrow twice recalls older history": {
+			setup: func() inputModel {
+				return newInputModel([]string{"deploy", "run"}, "")
+			},
+			actions: func(m inputModel) inputModel {
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				updated, _ = m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.Equal(t, "deploy", m.textInput.Value())
+				assert.Equal(t, 0, m.histIndex)
+			},
+		},
+		"down arrow restores saved text": {
+			setup: func() inputModel {
+				m := newInputModel([]string{"deploy", "run"}, "")
+				for _, r := range "ver" {
+					updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{r}})
+					m = updated.(inputModel)
+				}
+				return m
+			},
+			actions: func(m inputModel) inputModel {
+				// Go up - saves "ver", shows "run"
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				// Go back down - restores "ver"
+				updated, _ = m.Update(tea.KeyMsg{Type: tea.KeyDown})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.Equal(t, "ver", m.textInput.Value())
+				assert.Equal(t, 2, m.histIndex)
+			},
+		},
+		"up at oldest entry does nothing": {
+			setup: func() inputModel {
+				return newInputModel([]string{"deploy"}, "")
+			},
+			actions: func(m inputModel) inputModel {
+				updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				updated, _ = m.Update(tea.KeyMsg{Type: tea.KeyUp})
+				m = updated.(inputModel)
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.Equal(t, "deploy", m.textInput.Value())
+				assert.Equal(t, 0, m.histIndex)
+			},
+		},
+		"view renders border": {
+			setup: func() inputModel {
+				return newInputModel(nil, "")
+			},
+			actions: func(m inputModel) inputModel {
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				view := ansi.Strip(m.View())
+				assert.Contains(t, view, "─")
+				assert.Contains(t, view, "❯")
+			},
+		},
+		"view renders banner when version set": {
+			setup: func() inputModel {
+				m := newInputModel(nil, "v1.0.0")
+				m.width = 40
+				return m
+			},
+			actions: func(m inputModel) inputModel { return m },
+			assertFn: func(t *testing.T, m inputModel) {
+				view := ansi.Strip(m.View())
+				assert.Contains(t, view, "Slack CLI Shell")
+				assert.Contains(t, view, "v1.0.0")
+				assert.Contains(t, view, "❯")
+			},
+		},
+		"view renders no banner when version empty": {
+			setup: func() inputModel {
+				m := newInputModel(nil, "")
+				m.width = 40
+				return m
+			},
+			actions: func(m inputModel) inputModel { return m },
+			assertFn: func(t *testing.T, m inputModel) {
+				view := ansi.Strip(m.View())
+				assert.NotContains(t, view, "Slack CLI Shell")
+				assert.Contains(t, view, "❯")
+			},
+		},
+		"view is empty when done": {
+			setup: func() inputModel {
+				m := newInputModel(nil, "")
+				m.done = true
+				return m
+			},
+			actions: func(m inputModel) inputModel {
+				return m
+			},
+			assertFn: func(t *testing.T, m inputModel) {
+				assert.Equal(t, "", m.View())
+			},
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			m := tc.setup()
+			m = tc.actions(m)
+			tc.assertFn(t, m)
+		})
+	}
+}