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-command/src/commands/classified/external.rs

@@ -509,7 +509,7 @@ mod tests {
     #[cfg(feature = "which")]
     use futures::executor::block_on;
     #[cfg(feature = "which")]
-    use nu_engine::basic_evaluation_context;
+    use nu_engine::EvaluationContext;
     #[cfg(feature = "which")]
     use nu_errors::ShellError;
     #[cfg(feature = "which")]
@@ -534,7 +534,7 @@ mod tests {
 
         let input = InputStream::empty();
         let mut ctx =
-            basic_evaluation_context().expect("There was a problem creating a basic context.");
+            EvaluationContext::basic().expect("There was a problem creating a basic context.");
 
         assert!(
             run_external_command(cmd, &mut ctx, input, ExternalRedirection::Stdout)
@@ -548,7 +548,7 @@ mod tests {
     // async fn failure_run() -> Result<(), ShellError> {
     //     let cmd = ExternalBuilder::for_name("fail").build();
 
-    //     let mut ctx = crate::cli::basic_evaluation_context().expect("There was a problem creating a basic context.");
+    //     let mut ctx = crate::cli::EvaluationContext::basic().expect("There was a problem creating a basic context.");
     //     let stream = run_external_command(cmd, &mut ctx, None, false)
     //         .await?
     //         .expect("There was a problem running the external command.");

crates/nu-command/src/commands/config/command.rs

@@ -2,7 +2,7 @@ use crate::prelude::*;
 use nu_engine::CommandArgs;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
-use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
 use nu_stream::OutputStream;
 
 pub struct Command;
@@ -22,9 +22,16 @@ impl WholeStreamCommand for Command {
     }
 
     async fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        let name_span = args.call_info.name_tag.clone();
-        let name = args.call_info.name_tag;
-        let result = nu_data::config::read(name_span, &None)?;
+        let name = args.call_info.name_tag.clone();
+
+        let path = match args.scope.get_var("config-path") {
+            Some(Value {
+                value: UntaggedValue::Primitive(Primitive::FilePath(path)),
+                ..
+            }) => Some(path),
+            _ => nu_data::config::default_path().ok(),
+        };
+        let result = nu_data::config::read(&name, &path)?;
 
         Ok(futures::stream::iter(vec![ReturnSuccess::value(
             UntaggedValue::Row(result.into()).into_value(name),

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

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

crates/nu-command/src/commands/history.rs

@@ -1,6 +1,5 @@
 use crate::prelude::*;
-use nu_data::config::{Conf, NuConfig};
-use nu_engine::history_path;
+use nu_data::config::{path::history as history_path, NuConfig};
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
@@ -34,7 +33,7 @@ impl WholeStreamCommand for History {
 }
 
 async fn history(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let config: Box<dyn Conf> = Box::new(NuConfig::new());
+    let config = NuConfig::new();
     let tag = args.call_info.name_tag.clone();
     let (Arguments { clear }, _) = args.process().await?;
 

crates/nu-command/src/examples.rs

@@ -6,14 +6,12 @@ mod stub_generate;
 
 use double_echo::Command as DoubleEcho;
 use double_ls::Command as DoubleLs;
-use stub_generate::{mock_path, Command as StubOpen};
-
-use nu_engine::basic_evaluation_context;
 use nu_errors::ShellError;
 use nu_parser::ParserScope;
 use nu_protocol::hir::ClassifiedBlock;
 use nu_protocol::{ShellTypeName, Value};
 use nu_source::AnchorLocation;
+use stub_generate::{mock_path, Command as StubOpen};
 
 use crate::commands::{
     Append, BuildString, Each, Echo, First, Get, Keep, Last, Let, Nth, Select, StrCollect, Wrap,
@@ -26,7 +24,7 @@ use futures::executor::block_on;
 pub fn test_examples(cmd: Command) -> Result<(), ShellError> {
     let examples = cmd.examples();
 
-    let base_context = basic_evaluation_context()?;
+    let base_context = EvaluationContext::basic()?;
 
     base_context.add_commands(vec![
         // Command Doubles
@@ -92,7 +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 = basic_evaluation_context()?;
+    let base_context = EvaluationContext::basic()?;
 
     base_context.add_commands(vec![
         whole_stream_command(Echo {}),
@@ -149,7 +147,7 @@ pub fn test(cmd: impl WholeStreamCommand + 'static) -> Result<(), ShellError> {
 pub fn test_anchors(cmd: Command) -> Result<(), ShellError> {
     let examples = cmd.examples();
 
-    let base_context = basic_evaluation_context()?;
+    let base_context = EvaluationContext::basic()?;
 
     base_context.add_commands(vec![
         // Minimal restricted commands to aid in testing