Deliver a few fixes for explore command (#7310)

ref #6984

Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

crates/nu-explore/src/commands/nu.rs

@@ -6,7 +6,7 @@ use nu_protocol::{
 };
 
 use crate::{
-    nu_common::{collect_pipeline, run_nu_command},
+    nu_common::{collect_pipeline, has_simple_value, is_ignored_command, run_nu_command},
     pager::TableConfig,
     views::{Preview, RecordView, View},
 };
@@ -75,6 +75,13 @@ impl ViewCommand for NuCmd {
         stack: &mut Stack,
         value: Option<Value>,
     ) -> Result<Self::View> {
+        if is_ignored_command(&self.command) {
+            return Err(io::Error::new(
+                io::ErrorKind::Other,
+                "The command is ignored",
+            ));
+        }
+
         let value = value.unwrap_or_default();
 
         let pipeline = PipelineData::Value(value, None);
@@ -83,9 +90,7 @@ impl ViewCommand for NuCmd {
 
         let (columns, values) = collect_pipeline(pipeline);
 
-        let has_single_value = values.len() == 1 && values[0].len() == 1;
-        let is_simple_type = !matches!(&values[0][0], Value::List { .. } | Value::Record { .. });
-        if has_single_value && is_simple_type {
+        if has_simple_value(&values) {
             let config = &engine_state.config;
             let text = values[0][0].into_abbreviated_string(config);
             return Ok(NuView::Preview(Preview::new(&text)));

crates/nu-explore/src/lib.rs

@@ -7,7 +7,7 @@ mod views;
 
 use std::io;
 
-use nu_common::{collect_pipeline, CtrlC};
+use nu_common::{collect_pipeline, has_simple_value, CtrlC};
 use nu_protocol::{
     engine::{EngineState, Stack},
     PipelineData, Value,
@@ -38,9 +38,7 @@ pub fn run_pager(
         return p.run(engine_state, stack, ctrlc, view, commands);
     }
 
-    let has_single_value = data.len() == 1 && data[0].len() == 1;
-    let is_simple_type = !matches!(&data[0][0], Value::List { .. } | Value::Record { .. });
-    if has_single_value && is_simple_type {
+    if has_simple_value(&data) {
         let text = data[0][0].into_abbreviated_string(view_cfg.config);
 
         let view = Some(Page::new(Preview::new(&text), true));

crates/nu-explore/src/nu_common/command.rs

@@ -15,6 +15,10 @@ pub fn run_nu_command(
     eval_source2(&engine_state, stack, cmd.as_bytes(), "", current)
 }
 
+pub fn is_ignored_command(command: &str) -> bool {
+    command.starts_with("clear")
+}
+
 fn eval_source2(
     engine_state: &EngineState,
     stack: &mut Stack,
@@ -22,7 +26,7 @@ fn eval_source2(
     fname: &str,
     input: PipelineData,
 ) -> Result<PipelineData, ShellError> {
-    let (block, _) = {
+    let (mut block, _) = {
         let mut working_set = StateWorkingSet::new(engine_state);
         let (output, err) = parse(
             &mut working_set,
@@ -38,5 +42,13 @@ fn eval_source2(
         (output, working_set.render())
     };
 
+    // eval_block outputs all expressions expept the last to STDOUT;
+    // we don't wont that.
+    //
+    // So we LITERALLY ignore all expressions except the LAST.
+    if block.len() > 1 {
+        block.pipelines.drain(..block.pipelines.len() - 1);
+    }
+
     eval_block(engine_state, stack, &block, input, false, false)
 }

crates/nu-explore/src/nu_common/mod.rs

@@ -7,6 +7,7 @@ use std::{
     sync::{atomic::AtomicBool, Arc},
 };
 
+use nu_protocol::Value;
 use nu_table::TextStyle;
 
 pub use nu_ansi_term::{Color as NuColor, Style as NuStyle};
@@ -16,6 +17,11 @@ pub type NuText = (String, TextStyle);
 pub type CtrlC = Option<Arc<AtomicBool>>;
 pub type NuStyleTable = HashMap<String, NuStyle>;
 
-pub use command::run_nu_command;
+pub use command::{is_ignored_command, run_nu_command};
 pub use table::try_build_table;
 pub use value::{collect_input, collect_pipeline};
+
+pub fn has_simple_value(data: &[Vec<Value>]) -> bool {
+    let has_single_value = data.len() == 1 && data[0].len() == 1;
+    has_single_value && !matches!(&data[0][0], Value::List { .. } | Value::Record { .. })
+}

crates/nu-explore/src/views/interative.rs

@@ -12,7 +12,7 @@ use tui::{
 };
 
 use crate::{
-    nu_common::{collect_pipeline, run_nu_command},
+    nu_common::{collect_pipeline, is_ignored_command, run_nu_command},
     pager::{Frame, Report, TableConfig, Transition, ViewConfig, ViewInfo},
 };
 
@@ -176,6 +176,11 @@ impl View for InteractiveView<'_> {
                 Some(Transition::Ok)
             }
             KeyCode::Enter => {
+                if is_ignored_command(&self.command) {
+                    info.report = Some(Report::error(String::from("The command is ignored")));
+                    return Some(Transition::Ok);
+                }
+
                 let pipeline = PipelineData::Value(self.input.clone(), None);
                 let pipeline = run_nu_command(engine_state, stack, &self.command, pipeline);