console: add admin.clearHistory command (ethereum#15614)

console/console.go

@@ -192,6 +192,7 @@ func (c *Console) init(preload []string) error {
 	if obj := admin.Object(); obj != nil { // make sure the admin api is enabled over the interface
 		obj.Set("sleepBlocks", bridge.SleepBlocks)
 		obj.Set("sleep", bridge.Sleep)
+		obj.Set("clearHistory", c.clearHistory)
 	}
 	// Preload any JavaScript files before starting the console
 	for _, path := range preload {
@@ -216,6 +217,16 @@ func (c *Console) init(preload []string) error {
 	return nil
 }
 
+func (c *Console) clearHistory() {
+	c.history = nil
+	c.prompter.ClearHistory()
+	if err := os.Remove(c.histPath); err != nil {
+		fmt.Fprintln(c.printer, "can't delete history file:", err)
+	} else {
+		fmt.Fprintln(c.printer, "history file deleted")
+	}
+}
+
 // consoleOutput is an override for the console.log and console.error methods to
 // stream the output into the configured output stream instead of stdout.
 func (c *Console) consoleOutput(call otto.FunctionCall) otto.Value {

console/console_test.go

@@ -68,6 +68,7 @@ func (p *hookedPrompter) PromptConfirm(prompt string) (bool, error) {
 }
 func (p *hookedPrompter) SetHistory(history []string)              {}
 func (p *hookedPrompter) AppendHistory(command string)             {}
+func (p *hookedPrompter) ClearHistory()                            {}
 func (p *hookedPrompter) SetWordCompleter(completer WordCompleter) {}
 
 // tester is a console test environment for the console tests to operate on.

console/prompter.go

@@ -51,6 +51,9 @@ type UserPrompter interface {
 	// if and only if the prompt to append was a valid command.
 	AppendHistory(command string)
 
+	// ClearHistory clears the entire history
+	ClearHistory()
+
 	// SetWordCompleter sets the completion function that the prompter will call to
 	// fetch completion candidates when the user presses tab.
 	SetWordCompleter(completer WordCompleter)
@@ -158,6 +161,11 @@ func (p *terminalPrompter) AppendHistory(command string) {
 	p.State.AppendHistory(command)
 }
 
+// ClearHistory clears the entire history
+func (p *terminalPrompter) ClearHistory() {
+	p.State.ClearHistory()
+}
+
 // SetWordCompleter sets the completion function that the prompter will call to
 // fetch completion candidates when the user presses tab.
 func (p *terminalPrompter) SetWordCompleter(completer WordCompleter) {