add history session command (#6587)

crates/nu-cli/tests/completions.rs

@@ -469,13 +469,12 @@ fn variables_completions() {
     // Test completions for $nu
     let suggestions = completer.complete("$nu.", 4);
 
-    assert_eq!(10, suggestions.len());
+    assert_eq!(9, suggestions.len());
 
     let expected: Vec<String> = vec![
         "config-path".into(),
         "env-path".into(),
         "history-path".into(),
-        "history-session-id".into(),
         "home-path".into(),
         "loginshell-path".into(),
         "os-info".into(),
@@ -490,13 +489,9 @@ fn variables_completions() {
     // Test completions for $nu.h (filter)
     let suggestions = completer.complete("$nu.h", 5);
 
-    assert_eq!(3, suggestions.len());
+    assert_eq!(2, suggestions.len());
 
-    let expected: Vec<String> = vec![
+    let expected: Vec<String> = vec!["history-path".into(), "home-path".into()];
-        "history-path".into(),
-        "history-session-id".into(),
-        "home-path".into(),
-    ];
 
     // Match results
     match_suggestions(expected, suggestions);

crates/nu-command/src/default_context.rs

@@ -138,6 +138,7 @@ pub fn create_default_context() -> EngineState {
         bind_command! {
             History,
             Tutor,
+            HistorySession,
         };
 
         // Path

crates/nu-command/src/misc/history_session.rs

@@ -0,0 +1,43 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, Example, IntoPipelineData, PipelineData, Signature, Value};
+
+#[derive(Clone)]
+pub struct HistorySession;
+
+impl Command for HistorySession {
+    fn name(&self) -> &str {
+        "history session"
+    }
+
+    fn usage(&self) -> &str {
+        "Get the command history session"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("history session").category(Category::Misc)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            example: "history session",
+            description: "Get current history session",
+            result: None,
+        }]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        Ok(Value::Record {
+            cols: vec!["session-id".into()],
+            vals: vec![Value::int(engine_state.history_session_id, call.head)],
+            span: call.head,
+        }
+        .into_pipeline_data())
+    }
+}

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

@@ -1,5 +1,7 @@
 mod history;
+mod history_session;
 mod tutor;
 
 pub use history::History;
+pub use history_session::HistorySession;
 pub use tutor::Tutor;

crates/nu-engine/src/eval.rs

@@ -1434,9 +1434,6 @@ pub fn eval_variable(
             output_cols.push("os-info".into());
             output_vals.push(os_record);
 
-            output_cols.push("history-session-id".into());
-            output_vals.push(Value::int(engine_state.history_session_id, span));
-
             Ok(Value::Record {
                 cols: output_cols,
                 vals: output_vals,