Add hide-env to hide environment variables (#6313)

* Add hide-env to hide env vars; Cleanup tests

Also, there were some old unalias tests that I converted to hide.

* Add missing file

* Re-enable hide for env vars

* Fix test

* Rename did you mean error back

It was causing random tests to break

crates/nu-command/src/core_commands/hide.rs

@@ -19,11 +19,11 @@ impl Command for Hide {
     }
 
     fn usage(&self) -> &str {
-        "Hide symbols in the current scope"
+        "Hide definitions in the current scope"
     }
 
     fn extra_usage(&self) -> &str {
-        r#"Symbols are hidden by priority: First aliases, then custom commands, then environment variables.
+        r#"Definitions are hidden by priority: First aliases, then custom commands.
 
 This command is a parser keyword. For details, check:
   https://www.nushell.sh/book/thinking_in_nushell.html"#

crates/nu-command/src/core_commands/hide_env.rs

@@ -0,0 +1,75 @@
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    did_you_mean, Category, Example, PipelineData, ShellError, Signature, Span, Spanned,
+    SyntaxShape, Value,
+};
+
+#[derive(Clone)]
+pub struct HideEnv;
+
+impl Command for HideEnv {
+    fn name(&self) -> &str {
+        "hide-env"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("hide-env")
+            .rest(
+                "name",
+                SyntaxShape::String,
+                "environment variable names to hide",
+            )
+            .switch(
+                "ignore-errors",
+                "do not throw an error if an environment variable was not found",
+                Some('i'),
+            )
+            .category(Category::Core)
+    }
+
+    fn usage(&self) -> &str {
+        "Hide environment variables in the current scope"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let env_var_names: Vec<Spanned<String>> = call.rest(engine_state, stack, 0)?;
+        let ignore_errors = call.has_flag("ignore-errors");
+
+        for name in env_var_names {
+            if stack.remove_env_var(engine_state, &name.item).is_none() && !ignore_errors {
+                let all_names: Vec<String> = stack
+                    .get_env_var_names(engine_state)
+                    .iter()
+                    .cloned()
+                    .collect();
+                if let Some(closest_match) = did_you_mean(&all_names, &name.item) {
+                    return Err(ShellError::DidYouMeanCustom(
+                        format!("Environment variable '{}' not found", name.item),
+                        closest_match,
+                        name.span,
+                    ));
+                } else {
+                    return Err(ShellError::EnvVarNotFoundAtRuntime(name.item, name.span));
+                }
+            }
+        }
+
+        Ok(PipelineData::new(call.head))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Hide an environment variable",
+            example: r#"let-env HZ_ENV_ABC = 1; hide-env HZ_ENV_ABC; 'HZ_ENV_ABC' in (env).name"#,
+            result: Some(Value::boolean(false, Span::test_data())),
+        }]
+    }
+}

crates/nu-command/src/core_commands/mod.rs

@@ -17,6 +17,7 @@ mod extern_;
 mod for_;
 pub mod help;
 mod hide;
+mod hide_env;
 mod if_;
 mod ignore;
 mod let_;
@@ -46,6 +47,7 @@ pub use extern_::Extern;
 pub use for_::For;
 pub use help::Help;
 pub use hide::Hide;
+pub use hide_env::HideEnv;
 pub use if_::If;
 pub use ignore::Ignore;
 pub use let_::Let;

crates/nu-command/src/default_context.rs

@@ -47,6 +47,7 @@ pub fn create_default_context() -> EngineState {
             For,
             Help,
             Hide,
+            HideEnv,
             If,
             Ignore,
             Overlay,

crates/nu-protocol/src/shell_error.rs

@@ -626,6 +626,15 @@ Either make sure {0} is a string, or add a 'to_string' entry for it in ENV_CONVE
     #[diagnostic(code(nu::shell::name_not_found), url(docsrs))]
     DidYouMean(String, #[label("did you mean '{0}'?")] Span),
 
+    /// A name was not found. Did you mean a different name?
+    ///
+    /// ## Resolution
+    ///
+    /// The error message will suggest a possible match for what you meant.
+    #[error("{0}")]
+    #[diagnostic(code(nu::shell::did_you_mean_custom), url(docsrs))]
+    DidYouMeanCustom(String, String, #[label("did you mean '{1}'?")] Span),
+
     /// The given input must be valid UTF-8 for further processing.
     ///
     /// ## Resolution