1 files changed, 85 insertions, 0 deletions
diff --git a/ext/node/polyfills/internal/cli_table.ts b/ext/node/polyfills/internal/cli_table.ts
new file mode 100644
index 000000000..68cc6d044
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+++ b/ext/node/polyfills/internal/cli_table.ts
@@ -0,0 +1,85 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+
+import { getStringWidth } from "internal:deno_node/polyfills/internal/util/inspect.mjs";
+
+// The use of Unicode characters below is the only non-comment use of non-ASCII
+// Unicode characters in Node.js built-in modules. If they are ever removed or
+// rewritten with \u escapes, then a test will need to be (re-)added to Node.js
+// core to verify that Unicode characters work in built-ins.
+// Refs: https://github.com/nodejs/node/issues/10673
+const tableChars = {
+  middleMiddle: "─",
+  rowMiddle: "┼",
+  topRight: "┐",
+  topLeft: "┌",
+  leftMiddle: "├",
+  topMiddle: "┬",
+  bottomRight: "┘",
+  bottomLeft: "└",
+  bottomMiddle: "┴",
+  rightMiddle: "┤",
+  left: "│ ",
+  right: " │",
+  middle: " │ ",
+};
+
+const renderRow = (row: string[], columnWidths: number[]) => {
+  let out = tableChars.left;
+  for (let i = 0; i < row.length; i++) {
+    const cell = row[i];
+    const len = getStringWidth(cell);
+    const needed = (columnWidths[i] - len) / 2;
+    // round(needed) + ceil(needed) will always add up to the amount
+    // of spaces we need while also left justifying the output.
+    out += " ".repeat(needed) + cell +
+      " ".repeat(Math.ceil(needed));
+    if (i !== row.length - 1) {
+      out += tableChars.middle;
+    }
+  }
+  out += tableChars.right;
+  return out;
+};
+
+const table = (head: string[], columns: string[][]) => {
+  const rows: string[][] = [];
+  const columnWidths = head.map((h) => getStringWidth(h));
+  const longestColumn = Math.max(...columns.map((a) => a.length));
+
+  for (let i = 0; i < head.length; i++) {
+    const column = columns[i];
+    for (let j = 0; j < longestColumn; j++) {
+      if (rows[j] === undefined) {
+        rows[j] = [];
+      }
+      const value = rows[j][i] = Object.hasOwn(column, j) ? column[j] : "";
+      const width = columnWidths[i] || 0;
+      const counted = getStringWidth(value);
+      columnWidths[i] = Math.max(width, counted);
+    }
+  }
+
+  const divider = columnWidths.map((i) =>
+    tableChars.middleMiddle.repeat(i + 2)
+  );
+
+  let result = tableChars.topLeft +
+    divider.join(tableChars.topMiddle) +
+    tableChars.topRight + "\n" +
+    renderRow(head, columnWidths) + "\n" +
+    tableChars.leftMiddle +
+    divider.join(tableChars.rowMiddle) +
+    tableChars.rightMiddle + "\n";
+
+  for (const row of rows) {
+    result += `${renderRow(row, columnWidths)}\n`;
+  }
+
+  result += tableChars.bottomLeft +
+    divider.join(tableChars.bottomMiddle) +
+    tableChars.bottomRight;
+
+  return result;
+};
+export default table;