extract ask() into a function and a module

src/commands/kill.rs

@@ -1,5 +1,5 @@
 use std::convert::TryFrom;
-use std::io::{self, Write};
+use std::io::Write;
 
 use clap::ArgMatches;
 use chrono::{DateTime, Utc};
@@ -7,15 +7,10 @@ use chrono::{DateTime, Utc};
 use crate::error::{Error, Result};
 use crate::database::Database;
 use crate::config::Config;
+use crate::interactive::ask;
 
 use super::Command;
 
-fn read_line() -> String {
-    let mut pre_n = String::new();
-    io::stdin().read_line(&mut pre_n).unwrap();
-    pre_n
-}
-
 #[derive(Debug)]
 pub enum Args {
     Id(u64),
@@ -48,10 +43,7 @@ impl<'a> Command<'a> for KillCommand {
         match args {
             Args::Id(id) => {
                 if let Some(entry) = db.entry_by_id(id)? {
-                    write!(out, "are you sure you want to delete entry {}? ({}) [y/n] ", entry.id, entry.note.unwrap_or_else(|| "".into()))?;
-                    io::stdout().flush()?;
-
-                    if read_line().to_lowercase().starts_with('y') {
+                    if ask(out, &format!("are you sure you want to delete entry {}? ({})", entry.id, entry.note.unwrap_or_else(|| "".into())))? {
                         db.delete_entry_by_id(id)?;
                         writeln!(out, "It's dead")?;
                     } else {
@@ -64,10 +56,7 @@ impl<'a> Command<'a> for KillCommand {
             Args::Sheet(sheet) => {
                 let n = db.entries_by_sheet(&sheet, None, None)?.len();
 
-                write!(out, "are you sure you want to delete {} entries on sheet \"{}\"? [y/n] ", n, sheet)?;
-                io::stdout().flush()?;
-
-                if read_line().to_lowercase().starts_with('y') {
+                if ask(out, &format!("are you sure you want to delete {} entries on sheet \"{}\"?", n, sheet))? {
                     db.delete_entries_in_sheet(&sheet)?;
                     writeln!(out, "They're gone")?;
                 } else {

src/interactive.rs

@@ -0,0 +1,14 @@
+use std::io::{self, Write};
+
+fn read_line() -> io::Result<String> {
+    let mut pre_n = String::new();
+    io::stdin().read_line(&mut pre_n)?;
+    Ok(pre_n)
+}
+
+pub fn ask<W: Write>(out: &mut W, question: &str) -> io::Result<bool> {
+    write!(out, "{} [y/N] ", question)?;
+    out.flush()?;
+
+    Ok(read_line()?.to_lowercase().starts_with('y'))
+}

src/lib.rs

@@ -12,6 +12,7 @@ pub mod timeparse;
 pub mod regex;
 pub mod tabulate;
 pub mod old;
+pub mod interactive;
 
 #[cfg(test)]
 pub mod test_utils;