prompt: ClearHistory() to clear commands in history (#12)

Author: jedib0t

examples/prompt/sql/main.go

@@ -109,11 +109,9 @@ func main() {
 
 	// Prompt the user and handle each input in a loop until we are done for any
 	// reason (user wants to quit, etc.).
-	cmdNum := len(p.History())
 	for {
 		// Update the # of the command we are handling on the title bar
-		cmdNum++
-		segmentCmdNum.SetContent(fmt.Sprintf("#%d", cmdNum))
+		segmentCmdNum.SetContent(fmt.Sprint(len(p.History()) + 1))
 
 		// Prompt
 		input, err := p.Prompt(ctx)
@@ -127,6 +125,9 @@ func main() {
 		switch strings.ToLower(cmd) {
 		case "/?", "/help":
 			printHelp()
+		case "/clear":
+			p.ClearHistory()
+			fmt.Println("Cleared history.")
 		case "/quit":
 			fmt.Println("Bye!")
 			os.Exit(0)
@@ -186,6 +187,7 @@ func printHelp() {
 	fmt.Println(`SQL Prompt demo using github.com/jedib0t/go-prompter.
 
 * /?, /help    Prints this help text.
+* /clear       Clears History.
 * /quit        Exits the prompt.`)
 }
 

mocks/prompt/mock_prompter.go

@@ -105,9 +105,10 @@ func (h *History) Render(numItems int, dispWidth int) string {
 type historyCommandType string
 
 const (
-	historyCommandNone historyCommandType = ""
-	historyCommandList historyCommandType = "list"
-	historyCommandExec historyCommandType = "exec"
+	historyCommandNone  historyCommandType = ""
+	historyCommandClear historyCommandType = "clear"
+	historyCommandExec  historyCommandType = "exec"
+	historyCommandList  historyCommandType = "list"
 )
 
 type historyCommand struct {
@@ -135,10 +136,9 @@ func (p *prompt) processHistoryCommand(input string) *historyCommand {
 		input = strings.TrimSpace(input)
 		itemNum, err := strconv.Atoi(input)
 		if err != nil {
+			itemNum = 0
 			if input == p.historyExecPrefix { // prefix=!; input.original=!!; input=!
 				itemNum = len(p.History())
-			} else {
-				itemNum = 0
 			}
 		}
 		return &historyCommand{Type: historyCommandExec, Value: itemNum}

prompt/demo.gif

@@ -139,5 +139,5 @@ func TestPrompt_processHistoryCommand(t *testing.T) {
 	hc = p.processHistoryCommand("!!")
 	assert.NotNil(t, hc)
 	assert.Equal(t, historyCommandExec, hc.Type)
-	assert.Equal(t, 3, hc.Value)
+	assert.Equal(t, len(p.history.Commands), hc.Value)
 }

prompt/history.go

@@ -83,6 +83,11 @@ type prompt struct {
 	timeSyntaxGen               time.Duration
 }
 
+// ClearHistory clears all record of previously executed commands.
+func (p *prompt) ClearHistory() {
+	p.SetHistory(nil)
+}
+
 // CursorLocation returns the current location of the cursor on the prompt.
 func (p *prompt) CursorLocation() CursorLocation {
 	if p.buffer != nil {
@@ -268,6 +273,7 @@ func (p *prompt) SetHistory(commands []HistoryCommand) {
 // SetHistoryExecPrefix sets up the pattern used to exec command from history.
 // Example (prefix="!"):
 //   - !10 == execute 10th command
+//   - ! == execute last command in history
 func (p *prompt) SetHistoryExecPrefix(prefix string) {
 	p.historyExecPrefix = prefix
 }

prompt/history_test.go

@@ -1,7 +1,6 @@
 package prompt
 
 import (
-	"fmt"
 	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -17,8 +16,9 @@ func (p *prompt) handleHistoryExec(output *termenv.Output, cmdNum int) {
 
 	cmd := p.history.Get(cmdNum - 1)
 	if cmd == "" {
-		errMsg := fmt.Sprintf("ERROR: invalid command number: %v.\n\n", cmdNum)
-		_, _ = output.WriteString(p.style.Colors.Error.Sprintf(errMsg))
+		_, _ = output.WriteString(p.style.Colors.Error.Sprintf("ERROR: invalid command number: %v.\n", cmdNum))
+		_, _ = output.WriteString("\n")
+		p.linesRendered = make([]string, 0)
 		p.buffer.Reset()
 		return
 	}

prompt/prompt.go

@@ -20,6 +20,15 @@ var (
 	errFoo = errors.New("test-error-foo")
 )
 
+func TestPrompt_ClearHistory(t *testing.T) {
+	p := &prompt{}
+	p.SetHistory(testHistoryCommands)
+	assert.Len(t, p.History(), len(testHistoryCommands))
+
+	p.ClearHistory()
+	assert.Len(t, p.History(), 0)
+}
+
 func TestPrompt_CursorLocation(t *testing.T) {
 	p := &prompt{}
 	assert.Equal(t, CursorLocation{}, p.CursorLocation())

prompt/prompt_handle.go

@@ -10,6 +10,9 @@ import (
 // Prompter in the interface to create and manage a shell-like interactive
 // command prompt.
 type Prompter interface {
+	// ClearHistory clears all record of previously executed commands.
+	ClearHistory()
+
 	// CursorLocation returns the current location of the cursor on the prompt.
 	CursorLocation() CursorLocation
 
@@ -86,6 +89,7 @@ type Prompter interface {
 	// SetHistoryExecPrefix sets up the pattern used to exec command from
 	// history. Example (prefix="!"):
 	//   - !10 == execute 10th command
+	//   - ! == execute last command in history
 	SetHistoryExecPrefix(prefix string)
 
 	// SetHistoryListPrefix sets up the prefix used to list commands from