nu-cli refactor moving commands into their own crate nu-command (#2910)

* move commands, futures.rs, script.rs, utils

* move over maybe_print_errors

* add nu_command crate references to nu_cli

* in commands.rs open up to pub mod from pub(crate)

* nu-cli, nu-command, and nu tests are now passing

* cargo fmt

* clean up nu-cli/src/prelude.rs

* code cleanup

* for some reason lex.rs was not formatted, may be causing my error

* remove mod completion from lib.rs which was not being used along with quickcheck macros

* add in allow unused imports

* comment out one failing external test; comment out one failing internal test

* revert commenting out failing tests; something else might be going on; someone with a windows machine should check and see what is going on with these failing windows tests

* Update Cargo.toml

Extend the optional features to nu-command

Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>

crates/nu-command/src/utils/suggestions.rs

@@ -0,0 +1,21 @@
+use crate::did_you_mean;
+use nu_errors::ShellError;
+use nu_protocol::Value;
+use nu_source::Tagged;
+
+pub fn suggestions(tried: Tagged<&str>, for_value: &Value) -> ShellError {
+    let possibilities = did_you_mean(for_value, tried.to_string());
+
+    match possibilities {
+        Some(p) => ShellError::labeled_error(
+            "Unknown column",
+            format!("did you mean '{}'?", p[0]),
+            tried.tag(),
+        ),
+        None => ShellError::labeled_error(
+            "Unknown column",
+            "row does not contain this column",
+            tried.tag(),
+        ),
+    }
+}

crates/nu-command/src/utils/test_bins.rs

@@ -0,0 +1,89 @@
+use std::io::{self, BufRead, Write};
+
+pub fn cococo() {
+    let args: Vec<String> = args();
+
+    if args.len() > 1 {
+        // Write back out all the arguments passed
+        // if given at least 1 instead of chickens
+        // speaking co co co.
+        println!("{}", &args[1..].join(" "));
+    } else {
+        println!("cococo");
+    }
+}
+
+pub fn nonu() {
+    args().iter().skip(1).for_each(|arg| print!("{}", arg));
+}
+
+pub fn iecho() {
+    // println! panics if stdout gets closed, whereas writeln gives us an error
+    let mut stdout = io::stdout();
+    let _ = args()
+        .iter()
+        .skip(1)
+        .cycle()
+        .try_for_each(|v| writeln!(stdout, "{}", v));
+}
+
+pub fn fail() {
+    std::process::exit(1);
+}
+
+pub fn chop() {
+    if did_chop_arguments() {
+        // we are done and don't care about standard input.
+        std::process::exit(0);
+    }
+
+    // if no arguments given, chop from standard input and exit.
+    let stdin = io::stdin();
+    let mut stdout = io::stdout();
+
+    for line in stdin.lock().lines() {
+        if let Ok(given) = line {
+            let chopped = if given.is_empty() {
+                &given
+            } else {
+                let to = given.len() - 1;
+                &given[..to]
+            };
+
+            if let Err(_e) = writeln!(stdout, "{}", chopped) {
+                break;
+            }
+        }
+    }
+
+    std::process::exit(0);
+}
+
+fn did_chop_arguments() -> bool {
+    let args: Vec<String> = args();
+
+    if args.len() > 1 {
+        let mut arguments = args.iter();
+        arguments.next();
+
+        for arg in arguments {
+            let chopped = if arg.is_empty() {
+                &arg
+            } else {
+                let to = arg.len() - 1;
+                &arg[..to]
+            };
+
+            println!("{}", chopped);
+        }
+
+        return true;
+    }
+
+    false
+}
+
+fn args() -> Vec<String> {
+    // skip (--testbin bin_name args)
+    std::env::args().skip(2).collect()
+}