nu_cli refactor in preparation for a crate called nu_command (#2907)

* move basic_shell_manager to nu-engine

* move basic_evaluation_context to nu-engine

* fix failing test in feature which commands/classified/external.rs

crates/nu-cli/src/cli.rs

@@ -1,13 +1,7 @@
 use crate::commands::default_context::create_default_context;
-use crate::env::basic_host::BasicHost;
 use crate::line_editor::configure_ctrl_c;
 use nu_engine::run_block;
 use nu_engine::EvaluationContext;
-use nu_engine::{FilesystemShell, Scope, ShellManager};
-use parking_lot::Mutex;
-use std::sync::atomic::AtomicBool;
-use std::sync::atomic::AtomicUsize;
-use std::sync::Arc;
 
 #[allow(unused_imports)]
 pub(crate) use crate::script::{process_script, LineResult};
@@ -85,25 +79,6 @@ pub fn maybe_print_errors(context: &EvaluationContext, source: Text) -> bool {
     }
 }
 
-pub fn basic_shell_manager() -> Result<ShellManager, Box<dyn Error>> {
-    Ok(ShellManager {
-        current_shell: Arc::new(AtomicUsize::new(0)),
-        shells: Arc::new(Mutex::new(vec![Box::new(FilesystemShell::basic()?)])),
-    })
-}
-
-pub fn basic_evaluation_context() -> Result<EvaluationContext, Box<dyn Error>> {
-    Ok(EvaluationContext {
-        scope: Scope::new(),
-        host: Arc::new(parking_lot::Mutex::new(Box::new(BasicHost))),
-        current_errors: Arc::new(Mutex::new(vec![])),
-        ctrl_c: Arc::new(AtomicBool::new(false)),
-        user_recently_used_autoenv_untrust: Arc::new(AtomicBool::new(false)),
-        shell_manager: crate::cli::basic_shell_manager()?,
-        windows_drives_previous_cwd: Arc::new(Mutex::new(std::collections::HashMap::new())),
-    })
-}
-
 pub async fn run_script_file(
     file_contents: String,
     redirect_stdin: bool,
@@ -445,13 +420,14 @@ pub async fn parse_and_eval(line: &str, ctx: &EvaluationContext) -> Result<Strin
 
 #[cfg(test)]
 mod tests {
+    use nu_engine::basic_evaluation_context;
 
     #[quickcheck]
     fn quickcheck_parse(data: String) -> bool {
         let (tokens, err) = nu_parser::lex(&data, 0);
         let (lite_block, err2) = nu_parser::block(tokens);
         if err.is_none() && err2.is_none() {
-            let context = crate::cli::basic_evaluation_context().unwrap();
+            let context = basic_evaluation_context().unwrap();
             let _ = nu_parser::classify_block(&lite_block, &context.scope);
         }
         true

crates/nu-cli/src/commands/classified/external.rs

@@ -538,10 +538,11 @@ mod tests {
     #[cfg(feature = "which")]
     use futures::executor::block_on;
     #[cfg(feature = "which")]
+    use nu_engine::basic_evaluation_context;
+    #[cfg(feature = "which")]
     use nu_errors::ShellError;
     #[cfg(feature = "which")]
     use nu_test_support::commands::ExternalBuilder;
-
     // async fn read(mut stream: OutputStream) -> Option<Value> {
     //     match stream.try_next().await {
     //         Ok(val) => {
@@ -561,8 +562,8 @@ mod tests {
         let cmd = ExternalBuilder::for_name("i_dont_exist.exe").build();
 
         let input = InputStream::empty();
-        let mut ctx = crate::cli::basic_evaluation_context()
-            .expect("There was a problem creating a basic context.");
+        let mut ctx =
+            basic_evaluation_context().expect("There was a problem creating a basic context.");
 
         assert!(
             run_external_command(cmd, &mut ctx, input, ExternalRedirection::Stdout)

crates/nu-cli/src/commands/default_context.rs

@@ -1,9 +1,10 @@
 use crate::prelude::*;
+use nu_engine::basic_evaluation_context;
 use nu_engine::whole_stream_command;
 use std::error::Error;
 
 pub fn create_default_context(interactive: bool) -> Result<EvaluationContext, Box<dyn Error>> {
-    let context = crate::cli::basic_evaluation_context()?;
+    let context = basic_evaluation_context()?;
 
     {
         use crate::commands::*;

crates/nu-cli/src/env.rs

@@ -1,4 +1,3 @@
-pub(crate) mod basic_host;
 pub(crate) mod directory_specific_environment;
 pub(crate) mod environment;
 pub(crate) mod environment_syncer;

crates/nu-cli/src/env/basic_host.rs

@@ -1,77 +0,0 @@
-use nu_engine::Host;
-use nu_protocol::{errln, outln};
-use std::ffi::OsString;
-
-#[derive(Debug)]
-pub struct BasicHost;
-
-impl Host for BasicHost {
-    fn stdout(&mut self, out: &str) {
-        match out {
-            "\n" => outln!(""),
-            other => outln!("{}", other),
-        }
-    }
-
-    fn stderr(&mut self, out: &str) {
-        match out {
-            "\n" => errln!(""),
-            other => errln!("{}", other),
-        }
-    }
-
-    #[allow(unused_variables)]
-    fn vars(&mut self) -> Vec<(String, String)> {
-        #[cfg(not(target_arch = "wasm32"))]
-        {
-            std::env::vars().collect::<Vec<_>>()
-        }
-
-        #[cfg(target_arch = "wasm32")]
-        {
-            vec![]
-        }
-    }
-
-    #[allow(unused_variables)]
-    fn env_get(&mut self, key: OsString) -> Option<OsString> {
-        #[cfg(not(target_arch = "wasm32"))]
-        {
-            std::env::var_os(key)
-        }
-        #[cfg(target_arch = "wasm32")]
-        {
-            None
-        }
-    }
-
-    #[allow(unused_variables)]
-    fn env_set(&mut self, key: OsString, value: OsString) {
-        #[cfg(not(target_arch = "wasm32"))]
-        {
-            std::env::set_var(key, value);
-        }
-    }
-
-    #[allow(unused_variables)]
-    fn env_rm(&mut self, key: OsString) {
-        #[cfg(not(target_arch = "wasm32"))]
-        {
-            std::env::remove_var(key);
-        }
-    }
-
-    fn out_termcolor(&self) -> termcolor::StandardStream {
-        termcolor::StandardStream::stdout(termcolor::ColorChoice::Auto)
-    }
-
-    fn err_termcolor(&self) -> termcolor::StandardStream {
-        termcolor::StandardStream::stderr(termcolor::ColorChoice::Auto)
-    }
-
-    fn width(&self) -> usize {
-        let (mut term_width, _) = term_size::dimensions().unwrap_or((80, 20));
-        term_width -= 1;
-        term_width
-    }
-}

crates/nu-cli/src/env/environment_syncer.rs

@@ -155,6 +155,7 @@ mod tests {
     use super::EnvironmentSyncer;
     use indexmap::IndexMap;
     use nu_data::config::tests::FakeConfig;
+    use nu_engine::basic_evaluation_context;
     use nu_engine::Env;
     use nu_errors::ShellError;
     use nu_test_support::fs::Stub::FileWithContent;
@@ -170,7 +171,7 @@ mod tests {
     #[test]
     fn syncs_env_if_new_env_entry_is_added_to_an_existing_configuration() -> Result<(), ShellError>
     {
-        let mut ctx = crate::cli::basic_evaluation_context()?;
+        let mut ctx = basic_evaluation_context()?;
         ctx.host = Arc::new(Mutex::new(Box::new(nu_engine::FakeHost::new())));
 
         let mut expected = IndexMap::new();
@@ -273,7 +274,7 @@ mod tests {
     #[test]
     fn syncs_env_if_new_env_entry_in_session_is_not_in_configuration_file() -> Result<(), ShellError>
     {
-        let mut ctx = crate::cli::basic_evaluation_context()?;
+        let mut ctx = basic_evaluation_context()?;
         ctx.host = Arc::new(Mutex::new(Box::new(nu_engine::FakeHost::new())));
 
         let mut expected = IndexMap::new();
@@ -372,7 +373,7 @@ mod tests {
 
     #[test]
     fn nu_envs_have_higher_priority_and_does_not_get_overwritten() -> Result<(), ShellError> {
-        let mut ctx = crate::cli::basic_evaluation_context()?;
+        let mut ctx = basic_evaluation_context()?;
         ctx.host = Arc::new(Mutex::new(Box::new(nu_engine::FakeHost::new())));
 
         let mut expected = IndexMap::new();
@@ -448,7 +449,7 @@ mod tests {
     #[test]
     fn syncs_path_if_new_path_entry_in_session_is_not_in_configuration_file(
     ) -> Result<(), ShellError> {
-        let mut ctx = crate::cli::basic_evaluation_context()?;
+        let mut ctx = basic_evaluation_context()?;
         ctx.host = Arc::new(Mutex::new(Box::new(nu_engine::FakeHost::new())));
 
         let expected = std::env::join_paths(vec![
@@ -535,7 +536,7 @@ mod tests {
     #[test]
     fn nu_paths_have_higher_priority_and_new_paths_get_appended_to_the_end(
     ) -> Result<(), ShellError> {
-        let mut ctx = crate::cli::basic_evaluation_context()?;
+        let mut ctx = basic_evaluation_context()?;
         ctx.host = Arc::new(Mutex::new(Box::new(nu_engine::FakeHost::new())));
 
         let expected = std::env::join_paths(vec![

crates/nu-cli/src/examples.rs

@@ -1,3 +1,4 @@
+use nu_engine::basic_evaluation_context;
 use nu_errors::ShellError;
 use nu_parser::ParserScope;
 use nu_protocol::hir::ClassifiedBlock;
@@ -25,7 +26,7 @@ use serde::Deserialize;
 pub fn test_examples(cmd: Command) -> Result<(), ShellError> {
     let examples = cmd.examples();
 
-    let base_context = crate::cli::basic_evaluation_context()?;
+    let base_context = basic_evaluation_context()?;
 
     base_context.add_commands(vec![
         // Mocks
@@ -89,7 +90,7 @@ pub fn test_examples(cmd: Command) -> Result<(), ShellError> {
 pub fn test(cmd: impl WholeStreamCommand + 'static) -> Result<(), ShellError> {
     let examples = cmd.examples();
 
-    let base_context = crate::cli::basic_evaluation_context()?;
+    let base_context = basic_evaluation_context()?;
 
     base_context.add_commands(vec![
         whole_stream_command(Echo {}),
@@ -145,7 +146,7 @@ pub fn test(cmd: impl WholeStreamCommand + 'static) -> Result<(), ShellError> {
 pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
     let examples = cmd.examples();
 
-    let base_context = crate::cli::basic_evaluation_context()?;
+    let base_context = basic_evaluation_context()?;
 
     base_context.add_commands(vec![
         // Minimal restricted commands to aid in testing