add next entry check before printing the separator

emar-kar · emar-kar · commit 90a9854f4e54 · 2025-04-04T18:34:40.000+01:00
diff --git a/examples/basic.rs b/examples/basic.rs
@@ -11,7 +11,7 @@ use term_grid::{Direction, Filling, Grid, GridOptions};
 //  8 | 1024 |  131072 |  16777216 |  2147483648 |  274877906944 |  35184372088832
 // 16 | 2048 |  262144 |  33554432 |  4294967296 |  549755813888 |  70368744177664
 // 32 | 4096 |  524288 |  67108864 |  8589934592 | 1099511627776 | 140737488355328
-// 64 | 8192 | 1048576 | 134217728 | 17179869184 | 2199023255552 |
+// 64 | 8192 | 1048576 | 134217728 | 17179869184 | 2199023255552
 
 fn main() {
     let cells: Vec<_> = (0..48).map(|i| 2_isize.pow(i).to_string()).collect();
diff --git a/examples/tabs.rs b/examples/tabs.rs
@@ -11,7 +11,7 @@ use term_grid::{Direction, Filling, Grid, GridOptions};
 // 8···1024··131072···16777216···2147483648···274877906944↹··35184372088832␊
 // 16··2048··262144···33554432···4294967296···549755813888↹··70368744177664␊
 // 32··4096··524288···67108864···8589934592···1099511627776··140737488355328␊
-// 64··8192··1048576··134217728··17179869184··2199023255552··␊
+// 64··8192··1048576··134217728··17179869184··2199023255552␊
 
 fn main() {
     let cells: Vec<_> = (0..48).map(|i| 2_isize.pow(i).to_string()).collect();
diff --git a/src/lib.rs b/src/lib.rs
@@ -294,19 +294,25 @@ impl<T: AsRef<str>> fmt::Display for Grid<T> {
             // Current position on the line.
             let mut cursor: usize = 0;
             for x in 0..self.dimensions.widths.len() {
-                let num = match self.options.direction {
-                    Direction::LeftToRight => y * self.dimensions.widths.len() + x,
-                    Direction::TopToBottom => y + self.dimensions.num_lines * x,
+                let (num, next) = match self.options.direction {
+                    Direction::LeftToRight => (y * self.dimensions.widths.len() + x, 1),
+                    Direction::TopToBottom => {
+                        (y + self.dimensions.num_lines * x, self.dimensions.num_lines)
+                    }
                 };
 
                 // Abandon a line mid-way through if that’s where the cells end
                 if num >= self.cells.len() {
-                    continue;
+                    break;
                 }
 
+                // Last in row checks only the predifined grid width.
+                // It does not check if there will be more entries.
+                // For this purpose we define next value as well.
+                // This prevents printing separator after the actual last value in a row.
+                let last_in_row = x == self.dimensions.widths.len() - 1;
                 let contents = &self.cells[num];
                 let width = self.widths[num];
-                let last_in_row = x == self.dimensions.widths.len() - 1;
                 let col_width = self.dimensions.widths[x];
                 let padding_size = col_width - width;
 
@@ -324,7 +330,9 @@ impl<T: AsRef<str>> fmt::Display for Grid<T> {
                 // We also only call `write_str` when we actually need padding as
                 // another optimization.
                 f.write_str(contents.as_ref())?;
-                if !last_in_row {
+                // In case if this entry was the last on the current line,
+                // there is no need to check for separator or padding.
+                if !last_in_row && num + next < self.cells.len() {
                     // Special case if tab size was not set. Fill with spaces and separator.
                     if tab_size == 0 {
                         f.write_str(&padding[..padding_size])?;
diff --git a/tests/test.rs b/tests/test.rs
@@ -272,6 +272,32 @@ fn padding_bigger_than_widest() {
     assert_eq!(grid.to_string(), bits);
 }
 
+#[test]
+fn odd_number_of_entries() {
+    let cells = vec!["one", "two", "three", "four", "five"];
+    let grid = Grid::new(
+        cells.clone(),
+        GridOptions {
+            direction: Direction::LeftToRight,
+            filling: Filling::Spaces(2),
+            width: 15,
+        },
+    );
+
+    assert_eq!(grid.to_string(), "one    two\nthree  four\nfive\n");
+
+    let grid = Grid::new(
+        cells.clone(),
+        GridOptions {
+            direction: Direction::TopToBottom,
+            filling: Filling::Spaces(2),
+            width: 15,
+        },
+    );
+
+    assert_eq!(grid.to_string(), "one    four\ntwo    five\nthree\n");
+}
+
 // These test are based on the tests in uutils ls, to ensure we won't break
 // it while editing this library.
 mod uutils_ls {
