Fix issue with head on separation lines (#13291)

Hi there,

Seems to work

Though I haven't done a lot of testing.


![image](https://github.com/nushell/nushell/assets/20165848/c95aa8d4-a8d2-462c-afc9-35c48f8825f4)

![image](https://github.com/nushell/nushell/assets/20165848/1859dfe5-4a76-4776-a4e0-d3f53fc86862)

![image](https://github.com/nushell/nushell/assets/20165848/b46bb62b-a951-412d-b8fa-65cebcfbfed6)

![image](https://github.com/nushell/nushell/assets/20165848/bff0762e-42d4-41bf-b2c2-641c0436ca2e)

![image](https://github.com/nushell/nushell/assets/20165848/2c3c5664-9b90-44e4-befc-c250174cb630)


close #13287
cc: @fdncred 

PS: Yessssss I do remember about emojie issue..... 😞

crates/nu-table/src/table.rs

@@ -12,13 +12,17 @@ use tabled::{
         config::{AlignmentHorizontal, ColoredConfig, Entity, EntityMap, Position},
         dimension::CompleteDimensionVecRecords,
         records::{
-            vec_records::{CellInfo, VecRecords},
+            vec_records::{Cell, CellInfo, VecRecords},
             ExactRecords, PeekableRecords, Records, Resizable,
         },
     },
     settings::{
-        formatting::AlignmentStrategy, object::Segment, peaker::Peaker, themes::ColumnNames, Color,
+        formatting::AlignmentStrategy,
-        Modify, Padding, Settings, TableOption, Width,
+        object::{Columns, Segment},
+        peaker::Peaker,
+        themes::ColumnNames,
+        width::Truncate,
+        Color, Modify, Padding, Settings, TableOption, Width,
     },
     Table,
 };
@@ -216,7 +220,7 @@ fn build_table(
     }
 
     let pad = indent.0 + indent.1;
-    let widths = maybe_truncate_columns(&mut data, &cfg.theme, termwidth, pad);
+    let widths = maybe_truncate_columns(&mut data, &cfg, termwidth, pad);
     if widths.is_empty() {
         return None;
     }
@@ -269,20 +273,51 @@ fn set_indent(table: &mut Table, left: usize, right: usize) {
 fn set_border_head(table: &mut Table, with_footer: bool, wctrl: TableWidthCtrl) {
     if with_footer {
         let count_rows = table.count_rows();
+        let last_row_index = count_rows - 1;
+
+        // note: funnily last and row must be equal at this point but we do not rely on it just in case.
+
+        let mut first_row = GetRow(0, Vec::new());
+        let mut head_settings = GetRowSettings(0, AlignmentHorizontal::Left, None);
+        let mut last_row = GetRow(last_row_index, Vec::new());
+
+        table.with(&mut first_row);
+        table.with(&mut head_settings);
+        table.with(&mut last_row);
+
         table.with(
             Settings::default()
                 .with(wctrl)
                 .with(StripColorFromRow(0))
                 .with(StripColorFromRow(count_rows - 1))
-                .with(HeaderMove((0, 0), true))
+                .with(MoveRowNext::new(0, 0))
-                .with(HeaderMove((count_rows - 1 - 1, count_rows - 1), false)),
+                .with(MoveRowPrev::new(last_row_index - 1, last_row_index))
+                .with(SetLineHeaders::new(
+                    0,
+                    first_row.1,
+                    head_settings.1,
+                    head_settings.2.clone(),
+                ))
+                .with(SetLineHeaders::new(
+                    last_row_index - 1,
+                    last_row.1,
+                    head_settings.1,
+                    head_settings.2,
+                )),
         );
     } else {
+        let mut row = GetRow(0, Vec::new());
+        let mut row_opts = GetRowSettings(0, AlignmentHorizontal::Left, None);
+
+        table.with(&mut row);
+        table.with(&mut row_opts);
+
         table.with(
             Settings::default()
                 .with(wctrl)
                 .with(StripColorFromRow(0))
-                .with(HeaderMove((0, 0), true)),
+                .with(MoveRowNext::new(0, 0))
+                .with(SetLineHeaders::new(0, row.1, row_opts.1, row_opts.2)),
         );
     }
 }
@@ -324,11 +359,14 @@ impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for
                 max: self.max,
                 strategy: self.cfg.trim,
                 width: self.width,
+                do_as_head: self.cfg.header_on_border,
             }
             .change(rec, cfg, dim);
         } else if self.cfg.expand && self.max > total_width {
             Settings::new(SetDimensions(self.width), Width::increase(self.max))
                 .change(rec, cfg, dim)
+        } else {
+            SetDimensions(self.width).change(rec, cfg, dim);
         }
     }
 }
@@ -337,6 +375,7 @@ struct TableTrim {
     width: Vec<usize>,
     strategy: TrimStrategy,
     max: usize,
+    do_as_head: bool,
 }
 
 impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for TableTrim {
@@ -346,6 +385,44 @@ impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for
         cfg: &mut ColoredConfig,
         dims: &mut CompleteDimensionVecRecords<'_>,
     ) {
+        // we already must have been estimated that it's safe to do.
+        // and all dims will be suffitient
+        if self.do_as_head {
+            if recs.is_empty() {
+                return;
+            }
+
+            let headers = recs[0].to_owned();
+            for (i, head) in headers.into_iter().enumerate() {
+                let head_width = CellInfo::width(&head);
+
+                match &self.strategy {
+                    TrimStrategy::Wrap { try_to_keep_words } => {
+                        let mut wrap = Width::wrap(head_width);
+                        if *try_to_keep_words {
+                            wrap = wrap.keep_words();
+                        }
+
+                        Modify::new(Columns::single(i))
+                            .with(wrap)
+                            .change(recs, cfg, dims);
+                    }
+                    TrimStrategy::Truncate { suffix } => {
+                        let mut truncate = Width::truncate(self.max);
+                        if let Some(suffix) = suffix {
+                            truncate = truncate.suffix(suffix).suffix_try_color(true);
+                        }
+
+                        Modify::new(Columns::single(i))
+                            .with(truncate)
+                            .change(recs, cfg, dims);
+                    }
+                }
+            }
+
+            return;
+        }
+
         match self.strategy {
             TrimStrategy::Wrap { try_to_keep_words } => {
                 let mut wrap = Width::wrap(self.max).priority::<PriorityMax>();
@@ -460,19 +537,22 @@ fn load_theme(
 
 fn maybe_truncate_columns(
     data: &mut NuRecords,
-    theme: &TableTheme,
+    cfg: &NuTableConfig,
     termwidth: usize,
     pad: usize,
 ) -> Vec<usize> {
     const TERMWIDTH_THRESHOLD: usize = 120;
 
-    let truncate = if termwidth > TERMWIDTH_THRESHOLD {
+    let preserve_content = termwidth > TERMWIDTH_THRESHOLD;
+    let truncate = if cfg.header_on_border {
+        truncate_columns_by_head
+    } else if preserve_content {
         truncate_columns_by_columns
     } else {
         truncate_columns_by_content
     };
 
-    truncate(data, theme, pad, termwidth)
+    truncate(data, &cfg.theme, pad, termwidth)
 }
 
 // VERSION where we are showing AS LITTLE COLUMNS AS POSSIBLE but WITH AS MUCH CONTENT AS POSSIBLE.
@@ -627,6 +707,83 @@ fn truncate_columns_by_columns(
     widths
 }
 
+// VERSION where we are showing AS LITTLE COLUMNS AS POSSIBLE but WITH AS MUCH CONTENT AS POSSIBLE.
+fn truncate_columns_by_head(
+    data: &mut NuRecords,
+    theme: &TableTheme,
+    pad: usize,
+    termwidth: usize,
+) -> Vec<usize> {
+    const TRAILING_COLUMN_WIDTH: usize = 5;
+
+    let config = get_config(theme, false, None);
+    let mut widths = build_width(&*data, pad);
+    let total_width = get_total_width2(&widths, &config);
+    if total_width <= termwidth {
+        return widths;
+    }
+
+    if data.is_empty() {
+        return widths;
+    }
+
+    let head = &data[0];
+
+    let borders = config.get_borders();
+    let has_vertical = borders.has_vertical();
+
+    let mut width = borders.has_left() as usize + borders.has_right() as usize;
+    let mut truncate_pos = 0;
+    for (i, column_header) in head.iter().enumerate() {
+        let column_header_width = Cell::width(column_header);
+        width += column_header_width;
+
+        if i > 0 {
+            width += has_vertical as usize;
+        }
+
+        if width >= termwidth {
+            width -= column_header_width + (i > 0 && has_vertical) as usize;
+            break;
+        }
+
+        truncate_pos += 1;
+    }
+
+    // we don't need any truncation then (is it possible?)
+    if truncate_pos == head.len() {
+        return widths;
+    }
+
+    if truncate_pos == 0 {
+        return vec![];
+    }
+
+    truncate_columns(data, truncate_pos);
+    widths.truncate(truncate_pos);
+
+    // Append columns with a trailing column
+
+    let min_width = width;
+
+    let diff = termwidth - min_width;
+    let can_trailing_column_be_pushed = diff > TRAILING_COLUMN_WIDTH + has_vertical as usize;
+
+    if !can_trailing_column_be_pushed {
+        if data.count_columns() == 1 {
+            return vec![];
+        }
+
+        truncate_columns(data, data.count_columns() - 1);
+        widths.pop();
+    }
+
+    push_empty_column(data);
+    widths.push(3 + pad);
+
+    widths
+}
+
 /// The same as [`tabled::peaker::PriorityMax`] but prioritizes left columns first in case of equal width.
 #[derive(Debug, Default, Clone)]
 pub struct PriorityMax;
@@ -714,9 +871,8 @@ impl<R> TableOption<R, CompleteDimensionVecRecords<'_>, ColoredConfig> for SetDi
 }
 
 // it assumes no spans is used.
+// todo: Could be replaced by Dimension impl usage
 fn build_width(records: &NuRecords, pad: usize) -> Vec<usize> {
-    use tabled::grid::records::vec_records::Cell;
-
     let count_columns = records.count_columns();
     let mut widths = vec![0; count_columns];
     for columns in records.iter_rows() {
@@ -729,50 +885,156 @@ fn build_width(records: &NuRecords, pad: usize) -> Vec<usize> {
     widths
 }
 
-struct HeaderMove((usize, usize), bool);
+struct GetRow(usize, Vec<String>);
 
-impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for HeaderMove {
+impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for &mut GetRow {
+    fn change(
+        self,
+        recs: &mut NuRecords,
+        _: &mut ColoredConfig,
+        _: &mut CompleteDimensionVecRecords<'_>,
+    ) {
+        let row = self.0;
+        self.1 = recs[row].iter().map(|c| c.as_ref().to_owned()).collect();
+    }
+}
+
+struct GetRowSettings(usize, AlignmentHorizontal, Option<Color>);
+
+impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig>
+    for &mut GetRowSettings
+{
+    fn change(
+        self,
+        _: &mut NuRecords,
+        cfg: &mut ColoredConfig,
+        _: &mut CompleteDimensionVecRecords<'_>,
+    ) {
+        let row = self.0;
+        self.1 = *cfg.get_alignment_horizontal(Entity::Row(row));
+        self.2 = cfg
+            .get_colors()
+            .get_color((row, 0))
+            .cloned()
+            .map(Color::from);
+    }
+}
+
+struct SetLineHeaders {
+    line: usize,
+    columns: Vec<String>,
+    alignment: AlignmentHorizontal,
+    color: Option<Color>,
+}
+
+impl SetLineHeaders {
+    fn new(
+        line: usize,
+        columns: Vec<String>,
+        alignment: AlignmentHorizontal,
+        color: Option<Color>,
+    ) -> Self {
+        Self {
+            line,
+            columns,
+            alignment,
+            color,
+        }
+    }
+}
+
+impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for SetLineHeaders {
     fn change(
         self,
         recs: &mut NuRecords,
         cfg: &mut ColoredConfig,
         dims: &mut CompleteDimensionVecRecords<'_>,
     ) {
-        let (row, line) = self.0;
+        let mut columns = self.columns;
-        if self.1 {
+        match dims.get_widths() {
-            move_header_on_next(recs, cfg, dims, row, line);
+            Some(widths) => {
-        } else {
+                columns = columns
-            move_header_on_prev(recs, cfg, dims, row, line);
+                    .into_iter()
-        }
+                    .zip(widths.iter().map(|w| w.checked_sub(2).unwrap_or(*w))) // exclude padding; which is generally 2
+                    .map(|(s, width)| Truncate::truncate_text(&s, width).into_owned())
+                    .collect();
+            }
+            None => {
+                // we don't have widths cached; which means that NO widtds adjustmens were done
+                // which means we are OK to leave columns as they are.
+                //
+                // but we are actually always got to have widths at this point
+            }
+        };
+
+        set_column_names(
+            recs,
+            cfg,
+            dims,
+            columns,
+            self.line,
+            self.alignment,
+            self.color,
+        )
     }
 }
 
-fn move_header_on_next(
+struct MoveRowNext {
-    recs: &mut NuRecords,
-    cfg: &mut ColoredConfig,
-    dims: &mut CompleteDimensionVecRecords<'_>,
     row: usize,
     line: usize,
-) {
+}
+
+impl MoveRowNext {
+    fn new(row: usize, line: usize) -> Self {
+        Self { row, line }
+    }
+}
+
+struct MoveRowPrev {
+    row: usize,
+    line: usize,
+}
+
+impl MoveRowPrev {
+    fn new(row: usize, line: usize) -> Self {
+        Self { row, line }
+    }
+}
+
+impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for MoveRowNext {
+    fn change(
+        self,
+        recs: &mut NuRecords,
+        cfg: &mut ColoredConfig,
+        _: &mut CompleteDimensionVecRecords<'_>,
+    ) {
+        row_shift_next(recs, cfg, self.row, self.line);
+    }
+}
+
+impl TableOption<NuRecords, CompleteDimensionVecRecords<'_>, ColoredConfig> for MoveRowPrev {
+    fn change(
+        self,
+        recs: &mut NuRecords,
+        cfg: &mut ColoredConfig,
+        _: &mut CompleteDimensionVecRecords<'_>,
+    ) {
+        row_shift_prev(recs, cfg, self.row, self.line);
+    }
+}
+
+fn row_shift_next(recs: &mut NuRecords, cfg: &mut ColoredConfig, row: usize, line: usize) {
     let count_rows = recs.count_rows();
     let count_columns = recs.count_columns();
     let has_line = cfg.has_horizontal(line, count_rows);
     let has_next_line = cfg.has_horizontal(line + 1, count_rows);
-    let align = *cfg.get_alignment_horizontal(Entity::Row(row));
-    let color = cfg
-        .get_colors()
-        .get_color((row, 0))
-        .cloned()
-        .map(Color::from);
-
     if !has_line && !has_next_line {
         return;
     }
 
     if !has_line {
-        let head = remove_row(recs, row);
+        let _ = remove_row(recs, row);
         let count_rows = recs.count_rows();
-        set_column_names(recs, cfg, dims, head, line, align, color);
         shift_alignments_down(cfg, row, count_rows, count_columns);
         shift_colors_down(cfg, row, count_rows, count_columns);
         shift_lines_up(cfg, count_rows, &[line + 1]);
@@ -780,47 +1042,31 @@ fn move_header_on_next(
         return;
     }
 
-    let head = remove_row(recs, row);
+    let _ = remove_row(recs, row);
     let count_rows = recs.count_rows();
-    set_column_names(recs, cfg, dims, head, line, align, color);
     shift_alignments_down(cfg, row, count_rows, count_columns);
     shift_colors_down(cfg, row, count_rows, count_columns);
     remove_lines(cfg, count_rows, &[line + 1]);
     shift_lines_up(cfg, count_rows, &[count_rows]);
 }
 
-fn move_header_on_prev(
+fn row_shift_prev(recs: &mut NuRecords, cfg: &mut ColoredConfig, row: usize, line: usize) {
-    recs: &mut NuRecords,
-    cfg: &mut ColoredConfig,
-    dims: &mut CompleteDimensionVecRecords<'_>,
-    row: usize,
-    line: usize,
-) {
     let count_rows = recs.count_rows();
     let count_columns = recs.count_columns();
     let has_line = cfg.has_horizontal(line, count_rows);
     let has_prev_line = cfg.has_horizontal(line - 1, count_rows);
-    let align = *cfg.get_alignment_horizontal(Entity::Row(row));
-    let color = cfg
-        .get_colors()
-        .get_color((row, 0))
-        .cloned()
-        .map(Color::from);
-
     if !has_line && !has_prev_line {
         return;
     }
 
     if !has_line {
-        let head = remove_row(recs, row);
+        let _ = remove_row(recs, row);
         // shift_lines_down(table, &[line - 1]);
-        set_column_names(recs, cfg, dims, head, line - 1, align, color);
         return;
     }
 
-    let head = remove_row(recs, row);
+    let _ = remove_row(recs, row);
     let count_rows = count_rows - 1;
-    set_column_names(recs, cfg, dims, head, line - 1, align, color);
     shift_alignments_down(cfg, row, count_rows, count_columns);
     shift_colors_down(cfg, row, count_rows, count_columns);
     remove_lines(cfg, count_rows, &[line - 1]);