improved markdown table support for go port

main.go

@@ -16,6 +16,7 @@ import (
   "os"
   "os/exec"
   "path/filepath"
+  "regexp"
   "sort"
   "strconv"
   "strings"
@@ -154,6 +155,416 @@ func col(cfg Cfg) bool {
   return isTerminal(int(os.Stdout.Fd()))
 }
 
+type mdState struct {
+  inCode bool
+  lang   string
+}
+
+var (
+  reCode = regexp.MustCompile("`([^`]+)`")
+  reLink = regexp.MustCompile(`\[([^\]]+)\]\(([^)]+)\)`)
+  reBI1  = regexp.MustCompile(`\*\*\*(.*?)\*\*\*`)
+  reBI2  = regexp.MustCompile(`___(.*?)___`)
+  reB1   = regexp.MustCompile(`\*\*(.*?)\*\*`)
+  reB2   = regexp.MustCompile(`__(.*?)__`)
+  reI1   = regexp.MustCompile(`\*(.*?)\*`)
+  reI2   = regexp.MustCompile(`_(.*?)_`)
+  reS    = regexp.MustCompile(`~~(.*?)~~`)
+  reOrd  = regexp.MustCompile(`^(\d+\.)\s+(.*)`)
+)
+
+func renderInline(s string) string {
+  if !COL { return s }
+  var codes []string
+  s = reCode.ReplaceAllStringFunc(s, func(m string) string {
+    codes = append(codes, c(m[1:len(m)-1], 33))
+    return fmt.Sprintf("\x00CD%d\x00", len(codes)-1)
+  })
+  s = reLink.ReplaceAllStringFunc(s, func(m string) string {
+    sm := reLink.FindStringSubmatch(m)
+    if len(sm) == 3 { return c(sm[1], 4, 36) + " " + c("("+sm[2]+")", 2) }
+    return m
+  })
+  s = reBI1.ReplaceAllStringFunc(s, func(m string) string { return c(m[3:len(m)-3], 1, 3) })
+  s = reBI2.ReplaceAllStringFunc(s, func(m string) string { return c(m[3:len(m)-3], 1, 3) })
+  s = reB1.ReplaceAllStringFunc(s, func(m string) string { return c(m[2:len(m)-2], 1) })
+  s = reB2.ReplaceAllStringFunc(s, func(m string) string { return c(m[2:len(m)-2], 1) })
+  s = reI1.ReplaceAllStringFunc(s, func(m string) string { return c(m[1:len(m)-1], 3) })
+  s = reI2.ReplaceAllStringFunc(s, func(m string) string { return c(m[1:len(m)-1], 3) })
+  s = reS.ReplaceAllStringFunc(s, func(m string) string { return c(m[2:len(m)-2], 9) })
+  for i, code := range codes {
+    s = strings.ReplaceAll(s, fmt.Sprintf("\x00CD%d\x00", i), code)
+  }
+  return s
+}
+
+func renderMDLine(line string, st *mdState) string {
+  if !COL { return line }
+  trimmed := strings.TrimSpace(line)
+  if strings.HasPrefix(trimmed, "```") {
+    if !st.inCode {
+      st.inCode = true
+      st.lang = strings.TrimSpace(strings.TrimPrefix(trimmed, "```"))
+      title := ""
+      if st.lang != "" { title = " [ " + st.lang + " ]" }
+      return c("───"+title+"──────────────────────────────────────────", 2)
+    }
+    st.inCode = false
+    st.lang = ""
+    return c("───────────────────────────────────────────────────", 2)
+  }
+  if st.inCode {
+    return c("  ", 2) + c(line, 32)
+  }
+  if trimmed == "---" || trimmed == "***" || trimmed == "___" || trimmed == "----" || trimmed == "------" {
+    return c("───────────────────────────────────────────────────", 2)
+  }
+  if strings.HasPrefix(trimmed, "#") {
+    lvl := 0
+    for lvl < len(trimmed) && trimmed[lvl] == '#' { lvl++ }
+    if lvl < len(trimmed) && trimmed[lvl] == ' ' {
+      htext := strings.TrimSpace(trimmed[lvl:])
+      switch lvl {
+      case 1: return c("■ ", 35) + c(htext, 1, 37)
+      case 2: return c("▲ ", 34) + c(htext, 1, 36)
+      case 3: return c("● ", 32) + c(htext, 1, 32)
+      case 4: return c("◆ ", 33) + c(htext, 1, 33)
+      default: return c(htext, 1)
+      }
+    }
+  }
+  if strings.HasPrefix(trimmed, ">") {
+    qtext := strings.TrimSpace(strings.TrimPrefix(trimmed, ">"))
+    return c("▎ ", 34) + c(renderInline(qtext), 3)
+  }
+  if strings.HasPrefix(trimmed, "- [ ] ") || strings.HasPrefix(trimmed, "* [ ] ") {
+    return strings.Repeat(" ", len(line)-len(strings.TrimLeft(line, " "))) + c("☐ ", 33) + renderInline(trimmed[6:])
+  }
+  if strings.HasPrefix(trimmed, "- [x] ") || strings.HasPrefix(trimmed, "* [x] ") || strings.HasPrefix(trimmed, "- [X] ") || strings.HasPrefix(trimmed, "* [X] ") {
+    return strings.Repeat(" ", len(line)-len(strings.TrimLeft(line, " "))) + c("☑ ", 32) + renderInline(trimmed[6:])
+  }
+  if strings.HasPrefix(trimmed, "- ") || strings.HasPrefix(trimmed, "* ") || strings.HasPrefix(trimmed, "+ ") {
+    indent := strings.Repeat(" ", len(line)-len(strings.TrimLeft(line, " ")))
+    return indent + c("• ", 36) + renderInline(trimmed[2:])
+  }
+  if m := reOrd.FindStringSubmatch(trimmed); len(m) == 3 {
+    indent := strings.Repeat(" ", len(line)-len(strings.TrimLeft(line, " ")))
+    return indent + c(m[1]+" ", 33) + renderInline(m[2])
+  }
+  if strings.HasPrefix(trimmed, "|") && strings.HasSuffix(trimmed, "|") {
+    return renderInline(line)
+  }
+  return renderInline(line)
+}
+
+func isTableSep(cells []string) bool {
+  if len(cells) == 0 { return false }
+  for _, cell := range cells {
+    c := strings.ReplaceAll(strings.ReplaceAll(strings.TrimSpace(cell), "-", ""), ":", "")
+    if c != "" { return false }
+  }
+  return true
+}
+
+func parseTableCells(line string) []string {
+  trimmed := strings.TrimSpace(line)
+  if strings.HasPrefix(trimmed, "|") { trimmed = trimmed[1:] }
+  if strings.HasSuffix(trimmed, "|") { trimmed = trimmed[:len(trimmed)-1] }
+  parts := strings.Split(trimmed, "|")
+  cells := make([]string, len(parts))
+  for i, p := range parts { cells[i] = strings.TrimSpace(p) }
+  return cells
+}
+
+func isTableLine(line string) bool {
+  trimmed := strings.TrimSpace(line)
+  if !strings.Contains(trimmed, "|") { return false }
+  return strings.HasPrefix(trimmed, "|") || strings.HasSuffix(trimmed, "|")
+}
+
+func wrapCell(s string, width int) []string {
+  if width <= 0 { return []string{""} }
+  s = strings.ReplaceAll(s, "<br>", "\n")
+  s = strings.ReplaceAll(s, "<br/>", "\n")
+  s = strings.ReplaceAll(s, "<br />", "\n")
+  var lines []string
+  for _, p := range strings.Split(s, "\n") {
+    p = strings.TrimSpace(p)
+    if p == "" {
+      lines = append(lines, "")
+      continue
+    }
+    if visibleLen(p) <= width {
+      lines = append(lines, p)
+      continue
+    }
+    words := strings.Fields(p)
+    if len(words) == 0 {
+      lines = append(lines, "")
+      continue
+    }
+    var curLine string
+    var activeEsc string
+    updateActiveEsc := func(token string) {
+      for i := 0; i < len(token); {
+        if token[i] == 0x1b {
+          j := i + 1
+          if j < len(token) && token[j] == '[' {
+            j++
+            for j < len(token) && !(token[j] >= 0x40 && token[j] <= 0x7e) { j++ }
+            if j < len(token) { j++ }
+          }
+          esc := token[i:j]
+          if esc == "\033[0m" || esc == "\033[m" {
+            activeEsc = ""
+          } else {
+            activeEsc = esc
+          }
+          i = j
+        } else {
+          i++
+        }
+      }
+    }
+    flushLine := func() {
+      if curLine != "" {
+        out := curLine
+        if COL && activeEsc != "" && !strings.HasSuffix(out, "\033[0m") {
+          out += "\033[0m"
+        }
+        lines = append(lines, out)
+        curLine = ""
+      }
+    }
+    for _, word := range words {
+      wLen := visibleLen(word)
+      if wLen > width {
+        flushLine()
+        var chunk strings.Builder
+        cLen := 0
+        for i := 0; i < len(word); {
+          if word[i] == 0x1b {
+            j := i + 1
+            if j < len(word) && word[j] == '[' {
+              j++
+              for j < len(word) && !(word[j] >= 0x40 && word[j] <= 0x7e) { j++ }
+              if j < len(word) { j++ }
+            }
+            chunk.WriteString(word[i:j])
+            updateActiveEsc(word[i:j])
+            i = j
+            continue
+          }
+          r, size := utf8.DecodeRuneInString(word[i:])
+          if cLen >= width {
+            if COL && activeEsc != "" { chunk.WriteString("\033[0m") }
+            lines = append(lines, chunk.String())
+            chunk.Reset()
+            if COL && activeEsc != "" { chunk.WriteString(activeEsc) }
+            cLen = 0
+          }
+          chunk.WriteRune(r)
+          cLen++
+          i += size
+        }
+        if chunk.Len() > 0 { curLine = chunk.String() }
+        continue
+      }
+      cLen := visibleLen(curLine)
+      if curLine == "" {
+        curLine = word
+        updateActiveEsc(word)
+      } else if cLen+1+wLen <= width {
+        curLine += " " + word
+        updateActiveEsc(word)
+      } else {
+        flushLine()
+        if COL && activeEsc != "" {
+          curLine = activeEsc + word
+        } else {
+          curLine = word
+        }
+        updateActiveEsc(word)
+      }
+    }
+    flushLine()
+  }
+  if len(lines) == 0 { lines = []string{""} }
+  return lines
+}
+
+func renderTable(lines []string) []string {
+  if len(lines) == 0 { return nil }
+  var rows [][]string
+  var headerRow []string
+  hasHeader := false
+
+  for _, ln := range lines {
+    cells := parseTableCells(ln)
+    if isTableSep(cells) {
+      if len(rows) > 0 && !hasHeader {
+        headerRow = rows[len(rows)-1]
+        rows = rows[:len(rows)-1]
+        hasHeader = true
+      }
+      continue
+    }
+    rows = append(rows, cells)
+  }
+
+  if !hasHeader && len(lines) < 2 {
+    var out []string
+    var st mdState
+    for _, ln := range lines { out = append(out, renderMDLine(ln, &st)) }
+    return out
+  }
+
+  numCols := len(headerRow)
+  for _, r := range rows {
+    if len(r) > numCols { numCols = len(r) }
+  }
+  if numCols == 0 { return nil }
+
+  if hasHeader {
+    for len(headerRow) < numCols { headerRow = append(headerRow, "") }
+  }
+  for i := range rows {
+    for len(rows[i]) < numCols { rows[i] = append(rows[i], "") }
+  }
+
+  colWidths := make([]int, numCols)
+  for i := 0; i < numCols; i++ {
+    if hasHeader {
+      vl := visibleLen(headerRow[i])
+      if vl > colWidths[i] { colWidths[i] = vl }
+    }
+    for _, r := range rows {
+      vl := visibleLen(renderInline(r[i]))
+      if vl > colWidths[i] { colWidths[i] = vl }
+    }
+    if colWidths[i] < 3 { colWidths[i] = 3 }
+  }
+
+  maxTableWidth := termWidth()
+  if maxTableWidth < 20 { maxTableWidth = 80 }
+  overhead := 3*numCols + 1
+  availContent := maxTableWidth - overhead
+  if availContent < numCols*3 { availContent = numCols * 3 }
+
+  tot := 0
+  for _, w := range colWidths { tot += w }
+
+  for tot > availContent {
+    maxIdx := 0
+    maxVal := colWidths[0]
+    for i := 1; i < numCols; i++ {
+      if colWidths[i] > maxVal {
+        maxVal = colWidths[i]
+        maxIdx = i
+      }
+    }
+    if maxVal <= 3 { break }
+    colWidths[maxIdx]--
+    tot--
+  }
+
+  var res []string
+
+  var topParts []string
+  for _, w := range colWidths { topParts = append(topParts, strings.Repeat("─", w+2)) }
+  res = append(res, c("┌"+strings.Join(topParts, "┬")+"┐", 2))
+
+  if hasHeader {
+    headerCols := make([][]string, numCols)
+    maxHeaderLines := 1
+    for i, h := range headerRow {
+      wrapped := wrapCell(h, colWidths[i])
+      if len(wrapped) > maxHeaderLines { maxHeaderLines = len(wrapped) }
+      headerCols[i] = wrapped
+    }
+
+    for lineIdx := 0; lineIdx < maxHeaderLines; lineIdx++ {
+      var hCells []string
+      for i := 0; i < numCols; i++ {
+        txt := ""
+        if lineIdx < len(headerCols[i]) { txt = headerCols[i][lineIdx] }
+        rh := c(txt, 1, 36)
+        pad := strings.Repeat(" ", colWidths[i]-visibleLen(txt))
+        hCells = append(hCells, " "+rh+pad+" ")
+      }
+      res = append(res, c("│", 2)+strings.Join(hCells, c("│", 2))+c("│", 2))
+    }
+
+    var midParts []string
+    for _, w := range colWidths { midParts = append(midParts, strings.Repeat("─", w+2)) }
+    res = append(res, c("├"+strings.Join(midParts, "┼")+"┤", 2))
+  }
+
+  for _, r := range rows {
+    rowCols := make([][]string, numCols)
+    maxRowLines := 1
+    for i, cell := range r {
+      rc := renderInline(cell)
+      wrapped := wrapCell(rc, colWidths[i])
+      if len(wrapped) > maxRowLines { maxRowLines = len(wrapped) }
+      rowCols[i] = wrapped
+    }
+
+    for lineIdx := 0; lineIdx < maxRowLines; lineIdx++ {
+      var rCells []string
+      for i := 0; i < numCols; i++ {
+        txt := ""
+        if lineIdx < len(rowCols[i]) { txt = rowCols[i][lineIdx] }
+        pad := strings.Repeat(" ", colWidths[i]-visibleLen(txt))
+        rCells = append(rCells, " "+txt+pad+" ")
+      }
+      res = append(res, c("│", 2)+strings.Join(rCells, c("│", 2))+c("│", 2))
+    }
+  }
+
+  var botParts []string
+  for _, w := range colWidths { botParts = append(botParts, strings.Repeat("─", w+2)) }
+  res = append(res, c("└"+strings.Join(botParts, "┴")+"┘", 2))
+
+  return res
+}
+
+func renderMD(text string) string {
+  if !COL { return text }
+  lines := strings.Split(text, "\n")
+  var out []string
+  var st mdState
+  var tbl []string
+
+  flushTable := func() {
+    if len(tbl) > 0 {
+      out = append(out, renderTable(tbl)...)
+      tbl = nil
+    }
+  }
+
+  for _, ln := range lines {
+    trimmed := strings.TrimSpace(ln)
+    if strings.HasPrefix(trimmed, "```") {
+      flushTable()
+      out = append(out, renderMDLine(ln, &st))
+      continue
+    }
+    if st.inCode {
+      out = append(out, renderMDLine(ln, &st))
+      continue
+    }
+    if isTableLine(ln) {
+      tbl = append(tbl, ln)
+      continue
+    }
+    flushTable()
+    out = append(out, renderMDLine(ln, &st))
+  }
+  flushTable()
+  return strings.Join(out, "\n")
+}
+
 type Message struct {
   Role             string     `json:"role"`
   Content          *string    `json:"content"`
@@ -297,8 +708,19 @@ func llm(cfg *Cfg, msgs []Message, tools []map[string]any) (Message, error) {
 func parseStream(r io.Reader) (Message, error) {
   var content, reas string
   var rh, ch bool
+  var lineBuf string
+  var mdSt mdState
+  var tblBuf []string
   tcs := map[int]*ToolCall{}
   var order []int
+
+  flushTable := func() {
+    if len(tblBuf) > 0 {
+      for _, tln := range renderTable(tblBuf) { fmt.Println(tln) }
+      tblBuf = nil
+    }
+  }
+
   sc := bufio.NewScanner(r)
   sc.Buffer(make([]byte, 0, 64*1024), 4*1024*1024)
   for sc.Scan() {
@@ -319,8 +741,26 @@ func parseStream(r io.Reader) (Message, error) {
     if dl.Content != "" {
       if rh && !ch { fmt.Print("\n" + c("--- reasoning end ---", 36) + "\n\n") }
       ch = true
-      fmt.Print(dl.Content)
       content += dl.Content
+      lineBuf += dl.Content
+      for {
+        idx := strings.IndexByte(lineBuf, '\n')
+        if idx == -1 { break }
+        curLine := lineBuf[:idx]
+        lineBuf = lineBuf[idx+1:]
+        trimmed := strings.TrimSpace(curLine)
+        if strings.HasPrefix(trimmed, "```") {
+          flushTable()
+          fmt.Println(renderMDLine(curLine, &mdSt))
+        } else if mdSt.inCode {
+          fmt.Println(renderMDLine(curLine, &mdSt))
+        } else if isTableLine(curLine) {
+          tblBuf = append(tblBuf, curLine)
+        } else {
+          flushTable()
+          fmt.Println(renderMDLine(curLine, &mdSt))
+        }
+      }
     }
     for _, tc := range dl.ToolCalls {
       t, ok := tcs[tc.Index]
@@ -334,10 +774,17 @@ func parseStream(r io.Reader) (Message, error) {
       if tc.Function.Arguments != "" { t.Function.Arguments += tc.Function.Arguments }
     }
   }
+  flushTable()
+  if lineBuf != "" {
+    if !mdSt.inCode && isTableLine(lineBuf) {
+      tblBuf = append(tblBuf, lineBuf)
+      flushTable()
+    } else {
+      fmt.Println(renderMDLine(lineBuf, &mdSt))
+    }
+  }
   if rh && !ch {
     fmt.Print("\n" + c("--- reasoning end ---", 36) + "\n")
-  } else if ch {
-    fmt.Print("\n")
   }
   m := Message{Role: "assistant"}
   if content != "" { m.Content = strp(content) }
@@ -410,7 +857,7 @@ func AL(cfg *Cfg, msgs []Message, sp string, depth int) ([]Message, error) {
       if m.ReasoningContent != "" {
         fmt.Println(c("--- reasoning start ---", 36) + "\n" + c(m.ReasoningContent, 2) + "\n" + c("--- reasoning end ---", 36))
       }
-      if m.Content != nil { fmt.Println(*m.Content) }
+      if m.Content != nil { fmt.Println(renderMD(*m.Content)) }
     }
     if len(m.ToolCalls) == 0 { done = true; break }
     for _, tc := range m.ToolCalls {

main_test.go

@@ -1373,3 +1373,221 @@ func TestLLMForwardsRelevantParameters(t *testing.T) {
   }
 }
 
+// ---------- Markdown rendering tests ----------
+
+func TestRenderInline(t *testing.T) {
+  COL = true
+  defer func() { COL = false }()
+
+  // Code
+  out := renderInline("Use `go test -v` command")
+  if !strings.Contains(out, "\033[33mgo test -v\033[0m") {
+    t.Errorf("renderInline code = %q", out)
+  }
+
+  // Bold
+  out = renderInline("This is **bold** text")
+  if !strings.Contains(out, "\033[1mbold\033[0m") {
+    t.Errorf("renderInline bold = %q", out)
+  }
+
+  // Italic
+  out = renderInline("This is *italic* text")
+  if !strings.Contains(out, "\033[3mitalic\033[0m") {
+    t.Errorf("renderInline italic = %q", out)
+  }
+
+  // Bold + Italic
+  out = renderInline("This is ***important*** text")
+  if !strings.Contains(out, "\033[1;3mimportant\033[0m") {
+    t.Errorf("renderInline bold+italic = %q", out)
+  }
+
+  // Strikethrough
+  out = renderInline("This is ~~deleted~~ text")
+  if !strings.Contains(out, "\033[9mdeleted\033[0m") {
+    t.Errorf("renderInline strikethrough = %q", out)
+  }
+
+  // Link
+  out = renderInline("Visit [Go](https://go.dev) site")
+  if !strings.Contains(out, "\033[4;36mGo\033[0m") || !strings.Contains(out, "https://go.dev") {
+    t.Errorf("renderInline link = %q", out)
+  }
+
+  // Code shielding (asterisks inside code should not become italic)
+  out = renderInline("Run `foo * bar` now")
+  if !strings.Contains(out, "\033[33mfoo * bar\033[0m") {
+    t.Errorf("renderInline code shield = %q", out)
+  }
+}
+
+func TestRenderMDBlocks(t *testing.T) {
+  COL = true
+  defer func() { COL = false }()
+
+  // Headings
+  h1 := renderMD("# Title One")
+  if !strings.Contains(h1, "Title One") || !strings.Contains(h1, "\033[35m■ \033[0m") {
+    t.Errorf("renderMD H1 = %q", h1)
+  }
+  h2 := renderMD("## Subtitle")
+  if !strings.Contains(h2, "Subtitle") || !strings.Contains(h2, "\033[34m▲ \033[0m") {
+    t.Errorf("renderMD H2 = %q", h2)
+  }
+  h3 := renderMD("### Section")
+  if !strings.Contains(h3, "Section") || !strings.Contains(h3, "\033[32m● \033[0m") {
+    t.Errorf("renderMD H3 = %q", h3)
+  }
+
+  // Code block
+  codeMD := "```go\nfunc main() {\n  println(1)\n}\n```"
+  renderedCode := renderMD(codeMD)
+  if !strings.Contains(renderedCode, "[ go ]") || !strings.Contains(renderedCode, "println(1)") {
+    t.Errorf("renderMD code block = %q", renderedCode)
+  }
+
+  // Lists
+  ul := renderMD("- Item A\n- Item B")
+  if !strings.Contains(ul, "• ") || !strings.Contains(ul, "Item A") {
+    t.Errorf("renderMD unordered list = %q", ul)
+  }
+
+  ol := renderMD("1. Step 1\n2. Step 2")
+  if !strings.Contains(ol, "1. ") || !strings.Contains(ol, "Step 1") {
+    t.Errorf("renderMD ordered list = %q", ol)
+  }
+
+  tasks := renderMD("- [ ] Pending\n- [x] Finished")
+  if !strings.Contains(tasks, "☐ ") || !strings.Contains(tasks, "☑ ") {
+    t.Errorf("renderMD task list = %q", tasks)
+  }
+
+  // Blockquote
+  bq := renderMD("> Important quote")
+  if !strings.Contains(bq, "▎ ") || !strings.Contains(bq, "Important quote") {
+    t.Errorf("renderMD blockquote = %q", bq)
+  }
+
+  // Horizontal rule
+  hr := renderMD("---")
+  if !strings.Contains(hr, "────") {
+    t.Errorf("renderMD hr = %q", hr)
+  }
+
+  // Table
+  tbl := renderMD("| Col A | Col B |\n|---|---|\n| Val 1 | Val 2 |")
+  if !strings.Contains(tbl, "Col A") || !strings.Contains(tbl, "Val 1") {
+    t.Errorf("renderMD table = %q", tbl)
+  }
+}
+
+func TestRenderTableFormatting(t *testing.T) {
+  COL = true
+  defer func() { COL = false }()
+
+  raw := strings.Join([]string{
+    "| Name | Role | Location |",
+    "| :--- | :---: | ---: |",
+    "| Alice | `Lead` | New York |",
+    "| Bob | Developer | London |",
+  }, "\n")
+
+  rendered := renderMD(raw)
+  lines := strings.Split(rendered, "\n")
+  if len(lines) != 6 {
+    t.Fatalf("expected 6 table lines (top, header, mid, row1, row2, bot), got %d:\n%s", len(lines), rendered)
+  }
+
+  if !strings.HasPrefix(lines[0], "\033[2m┌") || !strings.HasSuffix(lines[0], "┐\033[0m") {
+    t.Errorf("top border = %q", lines[0])
+  }
+  if !strings.Contains(lines[1], "Name") || !strings.Contains(lines[1], "Role") || !strings.Contains(lines[1], "Location") {
+    t.Errorf("header row = %q", lines[1])
+  }
+  if !strings.HasPrefix(lines[2], "\033[2m├") || !strings.HasSuffix(lines[2], "┤\033[0m") {
+    t.Errorf("mid border = %q", lines[2])
+  }
+  if !strings.Contains(lines[3], "Alice") || !strings.Contains(lines[3], "New York") {
+    t.Errorf("row 1 = %q", lines[3])
+  }
+  if !strings.Contains(lines[4], "Bob") || !strings.Contains(lines[4], "London") {
+    t.Errorf("row 2 = %q", lines[4])
+  }
+  if !strings.HasPrefix(lines[5], "\033[2m└") || !strings.HasSuffix(lines[5], "┘\033[0m") {
+    t.Errorf("bot border = %q", lines[5])
+  }
+}
+
+func TestWrapCell(t *testing.T) {
+  COL = true
+  defer func() { COL = false }()
+
+  lines := wrapCell("Short text", 20)
+  if len(lines) != 1 || lines[0] != "Short text" {
+    t.Errorf("wrapCell short = %v", lines)
+  }
+
+  lines = wrapCell("The quick brown fox jumps over the lazy dog", 15)
+  if len(lines) < 3 {
+    t.Errorf("wrapCell long = %v", lines)
+  }
+  for _, l := range lines {
+    if visibleLen(l) > 15 {
+      t.Errorf("line %q visible length = %d > 15", l, visibleLen(l))
+    }
+  }
+
+  // With ANSI escape codes
+  styled := "\033[1;36mAlice In Wonderland\033[0m"
+  lines = wrapCell(styled, 10)
+  if len(lines) != 2 {
+    t.Errorf("wrapCell styled count = %d, lines = %v", len(lines), lines)
+  }
+  for _, l := range lines {
+    if visibleLen(l) > 10 {
+      t.Errorf("styled line %q length = %d > 10", l, visibleLen(l))
+    }
+  }
+}
+
+func TestRenderTableWidthConstraint(t *testing.T) {
+  COL = true
+  defer func() { COL = false }()
+
+  // Create an extra-wide table with long text
+  raw := strings.Join([]string{
+    "| Long Column Header One | Extremely Long Column Header Two That Would Definitely Overflow | Another Very Wide Column Header Three |",
+    "|---|---|---|",
+    "| Some detailed explanation that is very long and has lots of words in it | Another paragraph of text that continues on and on without stopping | Final column with even more long descriptions |",
+  }, "\n")
+
+  rendered := renderMD(raw)
+  lines := strings.Split(rendered, "\n")
+  maxW := termWidth()
+  if maxW < 20 { maxW = 80 }
+
+  for i, ln := range lines {
+    vl := visibleLen(ln)
+    if vl > maxW {
+      t.Errorf("table line %d visible length = %d, exceeds max width %d:\n%s", i, vl, maxW, ln)
+    }
+  }
+
+  // Ensure content was wrapped rather than dropped
+  if !strings.Contains(rendered, "detailed") || !strings.Contains(rendered, "explanation") || !strings.Contains(rendered, "paragraph") {
+    t.Errorf("rendered table should contain all words wrapped across lines:\n%s", rendered)
+  }
+}
+
+func TestRenderMDNoColorFallback(t *testing.T) {
+  COL = false
+  raw := "# Heading\n**bold** and `code`\n- list item"
+  out := renderMD(raw)
+  if out != raw {
+    t.Errorf("renderMD with COL=false should return raw text, got %q", out)
+  }
+}
+
+
+