History, more test coverage improvements, and refactorings. (#3217)

Improvements overall to Nu. Also among the changes here, we can also be more confident towards incorporating `3041`. End to end tests for checking envs properly exported to externals is not added here (since it's in the other PR)

A few things added in this PR (probably forgetting some too)

* no writes happen to history during test runs.
* environment syncing end to end coverage added.
* clean up / refactorings few areas.
* testing API for finer control (can write tests passing more than one pipeline)
* can pass environment variables in tests that nu will inherit when running.

* No longer needed.

* no longer under a module. No need to use super.

crates/nu-engine/src/basic_evaluation_context.rs

@@ -1,20 +0,0 @@
-use crate::basic_shell_manager;
-use crate::env::basic_host::BasicHost;
-use crate::EvaluationContext;
-use crate::Scope;
-use parking_lot::Mutex;
-use std::error::Error;
-use std::sync::atomic::AtomicBool;
-use std::sync::Arc;
-
-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: basic_shell_manager::basic_shell_manager()?,
-        windows_drives_previous_cwd: Arc::new(Mutex::new(std::collections::HashMap::new())),
-    })
-}

crates/nu-engine/src/basic_shell_manager.rs

@@ -1,14 +0,0 @@
-use crate::filesystem::filesystem_shell::FilesystemShell;
-use crate::shell::shell_manager::ShellManager;
-
-use parking_lot::Mutex;
-use std::error::Error;
-use std::sync::atomic::AtomicUsize;
-use std::sync::Arc;
-
-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()?)])),
-    })
-}

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

@@ -7,6 +7,21 @@ use std::ffi::OsString;
 #[derive(Debug)]
 pub struct BasicHost;
 
+pub fn print_err(err: ShellError, source: &Text) {
+    if let Some(diag) = err.into_diagnostic() {
+        let source = source.to_string();
+        let mut files = codespan_reporting::files::SimpleFiles::new();
+        files.add("shell", source);
+
+        let writer = termcolor::StandardStream::stderr(termcolor::ColorChoice::Auto);
+        let config = codespan_reporting::term::Config::default();
+
+        let _ = std::panic::catch_unwind(move || {
+            let _ = codespan_reporting::term::emit(&mut writer.lock(), &config, &files, &diag);
+        });
+    }
+}
+
 impl Host for BasicHost {
     fn stdout(&mut self, out: &str) {
         match out {
@@ -23,18 +38,7 @@ impl Host for BasicHost {
     }
 
     fn print_err(&mut self, err: ShellError, source: &Text) {
-        if let Some(diag) = err.into_diagnostic() {
-            let source = source.to_string();
-            let mut files = codespan_reporting::files::SimpleFiles::new();
-            files.add("shell", source);
-
-            let writer = termcolor::StandardStream::stderr(termcolor::ColorChoice::Auto);
-            let config = codespan_reporting::term::Config::default();
-
-            let _ = std::panic::catch_unwind(move || {
-                let _ = codespan_reporting::term::emit(&mut writer.lock(), &config, &files, &diag);
-            });
-        }
+        print_err(err, source);
     }
 
     #[allow(unused_variables)]

crates/nu-engine/src/evaluate/variables.rs

@@ -1,13 +1,24 @@
 use crate::evaluate::scope::Scope;
-use crate::history_path::history_path;
+use nu_data::config::NuConfig;
 use nu_errors::ShellError;
 use nu_protocol::{Primitive, TaggedDictBuilder, UntaggedValue, Value};
 use nu_source::Tag;
 
 pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
-    let env = &scope.get_env_vars();
     let tag = tag.into();
 
+    let env = &scope.get_env_vars();
+
+    let config = if let Some(Value {
+        value: UntaggedValue::Primitive(Primitive::FilePath(path)),
+        ..
+    }) = scope.get_var("config-path")
+    {
+        NuConfig::with(Some(path).map(|p| p.into_os_string()))
+    } else {
+        NuConfig::new()
+    };
+
     let mut nu_dict = TaggedDictBuilder::new(&tag);
 
     let mut dict = TaggedDictBuilder::new(&tag);
@@ -18,16 +29,10 @@ pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
     }
     nu_dict.insert_value("env", dict.into_value());
 
-    let config_file = match scope.get_var("config-path") {
-        Some(Value {
-            value: UntaggedValue::Primitive(Primitive::FilePath(path)),
-            ..
-        }) => Some(path),
-        _ => None,
-    };
-
-    let config = nu_data::config::read(&tag, &config_file)?;
-    nu_dict.insert_value("config", UntaggedValue::row(config).into_value(&tag));
+    nu_dict.insert_value(
+        "config",
+        UntaggedValue::row(config.vars.clone()).into_value(&tag),
+    );
 
     let mut table = vec![];
     for v in env.iter() {
@@ -49,15 +54,9 @@ pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
     let temp = std::env::temp_dir();
     nu_dict.insert_value("temp-dir", UntaggedValue::filepath(temp).into_value(&tag));
 
-    let config = if let Some(path) = config_file {
-        path
-    } else {
-        nu_data::config::default_path()?
-    };
-
     nu_dict.insert_value(
         "config-path",
-        UntaggedValue::filepath(config).into_value(&tag),
+        UntaggedValue::filepath(nu_data::config::path::source_file(&config)).into_value(&tag),
     );
 
     #[cfg(feature = "rustyline-support")]
@@ -69,11 +68,9 @@ pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
         );
     }
 
-    let config: Box<dyn nu_data::config::Conf> = Box::new(nu_data::config::NuConfig::new());
-    let history = history_path(&config);
     nu_dict.insert_value(
         "history-path",
-        UntaggedValue::filepath(history).into_value(&tag),
+        UntaggedValue::filepath(nu_data::config::path::history(&config)).into_value(&tag),
     );
 
     Ok(nu_dict.into_value())

crates/nu-engine/src/evaluation_context.rs

@@ -1,13 +1,13 @@
 use crate::call_info::UnevaluatedCallInfo;
 use crate::command_args::CommandArgs;
-use crate::env::host::Host;
+use crate::env::{basic_host::BasicHost, host::Host};
 use crate::evaluate::scope::Scope;
 use crate::shell::shell_manager::ShellManager;
 use crate::whole_stream_command::Command;
 use indexmap::IndexMap;
 use nu_errors::ShellError;
 use nu_protocol::hir;
-use nu_source::Tag;
+use nu_source::{Tag, Text};
 use nu_stream::{InputStream, OutputStream};
 use parking_lot::Mutex;
 use std::sync::atomic::AtomicBool;
@@ -27,6 +27,18 @@ pub struct EvaluationContext {
 }
 
 impl EvaluationContext {
+    pub fn basic() -> Result<EvaluationContext, ShellError> {
+        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: ShellManager::basic()?,
+            windows_drives_previous_cwd: Arc::new(Mutex::new(std::collections::HashMap::new())),
+        })
+    }
+
     pub fn from_args(args: &CommandArgs) -> EvaluationContext {
         EvaluationContext {
             scope: args.scope.clone(),
@@ -121,3 +133,18 @@ impl EvaluationContext {
         output
     }
 }
+
+pub fn maybe_print_errors(context: &EvaluationContext, source: Text) -> bool {
+    let errors = context.current_errors.clone();
+    let mut errors = errors.lock();
+
+    if errors.len() > 0 {
+        let error = errors[0].clone();
+        *errors = vec![];
+
+        context.host.lock().print_err(error, &source);
+        true
+    } else {
+        false
+    }
+}

crates/nu-engine/src/history_path.rs

@@ -1,22 +0,0 @@
-use nu_data::config::Conf;
-use std::path::PathBuf;
-
-const DEFAULT_LOCATION: &str = "history.txt";
-
-pub fn history_path(config: &dyn Conf) -> PathBuf {
-    let default_path = nu_data::config::user_data()
-        .map(|mut p| {
-            p.push(DEFAULT_LOCATION);
-            p
-        })
-        .unwrap_or_else(|_| PathBuf::from(DEFAULT_LOCATION));
-
-    config
-        .var("history-path")
-        .map_or(default_path.clone(), |custom_path| {
-            match custom_path.as_string() {
-                Ok(path) => PathBuf::from(path),
-                Err(_) => default_path,
-            }
-        })
-}

crates/nu-engine/src/lib.rs

@@ -1,25 +1,19 @@
-pub mod basic_evaluation_context;
-pub mod basic_shell_manager;
 mod call_info;
 mod command_args;
 pub mod deserializer;
 pub mod documentation;
 mod env;
 mod evaluate;
-mod evaluation_context;
+pub mod evaluation_context;
 mod example;
 pub mod filesystem;
-mod history_path;
 mod maybe_text_codec;
 pub mod plugin;
-pub mod print;
 mod runnable_context;
 pub mod script;
 pub mod shell;
 mod whole_stream_command;
 
-pub use crate::basic_evaluation_context::basic_evaluation_context;
-pub use crate::basic_shell_manager::basic_shell_manager;
 pub use crate::call_info::UnevaluatedCallInfo;
 pub use crate::command_args::{
     CommandArgs, EvaluatedCommandArgs, EvaluatedWholeStreamCommandArgs, RawCommandArgs,
@@ -36,7 +30,6 @@ pub use crate::example::Example;
 pub use crate::filesystem::dir_info::{DirBuilder, DirInfo, FileInfo};
 pub use crate::filesystem::filesystem_shell::FilesystemShell;
 pub use crate::filesystem::path;
-pub use crate::history_path::history_path;
 pub use crate::maybe_text_codec::{MaybeTextCodec, StringOrBinary};
 pub use crate::runnable_context::RunnableContext;
 pub use crate::shell::help_shell::{command_dict, HelpShell};

crates/nu-engine/src/print.rs

@@ -1,18 +0,0 @@
-use nu_source::Text;
-
-use crate::EvaluationContext;
-
-pub fn maybe_print_errors(context: &EvaluationContext, source: Text) -> bool {
-    let errors = context.current_errors.clone();
-    let mut errors = errors.lock();
-
-    if errors.len() > 0 {
-        let error = errors[0].clone();
-        *errors = vec![];
-
-        context.host.lock().print_err(error, &source);
-        true
-    } else {
-        false
-    }
-}

crates/nu-engine/src/script.rs

@@ -1,5 +1,5 @@
+use crate::path::canonicalize;
 use crate::run_block;
-use crate::{path::canonicalize, print::maybe_print_errors};
 use crate::{MaybeTextCodec, StringOrBinary};
 use futures::StreamExt;
 use futures_codec::FramedRead;
@@ -11,7 +11,7 @@ use nu_protocol::hir::{
 use nu_protocol::{Primitive, ReturnSuccess, UntaggedValue, Value};
 use nu_stream::{InputStream, ToInputStream};
 
-use crate::EvaluationContext;
+use crate::{evaluation_context, EvaluationContext};
 use log::{debug, trace};
 use nu_source::{Span, Tag, Text};
 use std::iter::Iterator;
@@ -244,19 +244,16 @@ pub async fn run_script_standalone(
                 }
             };
 
-            maybe_print_errors(&context, Text::from(line));
+            evaluation_context::maybe_print_errors(&context, Text::from(line));
             if error_code != 0 && exit_on_error {
                 std::process::exit(error_code);
             }
         }
 
         LineResult::Error(line, err) => {
-            context
-                .host
-                .lock()
-                .print_err(err, &Text::from(line.clone()));
+            context.with_host(|host| host.print_err(err, &Text::from(line.clone())));
 
-            maybe_print_errors(&context, Text::from(line));
+            evaluation_context::maybe_print_errors(&context, Text::from(line));
             if exit_on_error {
                 std::process::exit(1);
             }

crates/nu-engine/src/shell/shell_manager.rs

@@ -1,10 +1,12 @@
 use crate::command_args::EvaluatedWholeStreamCommandArgs;
 use crate::maybe_text_codec::StringOrBinary;
-use crate::shell::Shell;
 use futures::Stream;
 use nu_stream::OutputStream;
 
+use crate::filesystem::filesystem_shell::FilesystemShell;
 use crate::shell::shell_args::{CdArgs, CopyArgs, LsArgs, MkdirArgs, MvArgs, RemoveArgs};
+use crate::shell::Shell;
+
 use encoding_rs::Encoding;
 use nu_errors::ShellError;
 use nu_source::{Span, Tag};
@@ -20,6 +22,13 @@ pub struct ShellManager {
 }
 
 impl ShellManager {
+    pub fn basic() -> Result<Self, ShellError> {
+        Ok(ShellManager {
+            current_shell: Arc::new(AtomicUsize::new(0)),
+            shells: Arc::new(Mutex::new(vec![Box::new(FilesystemShell::basic()?)])),
+        })
+    }
+
     pub fn insert_at_current(&self, shell: Box<dyn Shell + Send>) {
         self.shells.lock().push(shell);
         self.current_shell