Function renderTreeNode

packages/cli/src/commands/dag.ts:294–352

* Render a node and its subtree in tree format. * @param varsDisplay - Optional variable flow annotation (e.g., " via x, y"). When provided, uses arrow connector.

(
  nodeId: string,
  prefix: string,
  isLast: boolean,
  childrenMap: Map<string, { id: string; variables: string[] }[]>,
  nodeMap: Map<string, DagNode>,
  blockMap: BlockMap,
  rendered: Set<string>,
  c: ReturnType<typeof getChalk>,
  varsDisplay = ''
)

 * @param varsDisplay - Optional variable flow annotation (e.g., " via x, y"). When provided, uses arrow connector.
 */
function renderTreeNode(
  nodeId: string,
  prefix: string,
  isLast: boolean,
  childrenMap: Map<string, { id: string; variables: string[] }[]>,
  nodeMap: Map<string, DagNode>,
  blockMap: BlockMap,
  rendered: Set<string>,
  c: ReturnType<typeof getChalk>,
  varsDisplay = ''
): void {
  const info = blockMap.get(nodeId)
  const node = nodeMap.get(nodeId)
  const label = info?.label ?? nodeId

  // Tree connectors: use arrow (─►) for child nodes with variable flow, plain (──) for roots
  const isChildNode = varsDisplay !== ''
  const connector = isLast ? (isChildNode ? '└─► ' : '└── ') : isChildNode ? '├─► ' : '├── '
  const childPrefix = isLast ? '    ' : '│   '

  // Check if this node was already rendered (DAG handling)
  const alreadyRendered = rendered.has(nodeId)
  rendered.add(nodeId)

  // Render the node line
  const typeIndicator = c.dim(`[${info?.type ?? 'unknown'}]`)
  if (alreadyRendered) {
    output(`${prefix}${connector}${c.cyan(label)} ${typeIndicator}${varsDisplay} ${c.yellow('*')}`)
    return
  }

  output(`${prefix}${connector}${c.cyan(label)} ${typeIndicator}${varsDisplay}`)

  // Show defined variables if any
  const outputVars = node?.outputVariables ?? []
  if (outputVars.length > 0) {
    output(`${prefix}${childPrefix}${c.dim('defines:')} ${c.green(outputVars.join(', '))}`)
  }

  // Get and render children
  const children = buildSortedChildren(nodeId, childrenMap, nodeMap)
  for (let i = 0; i < children.length; i++) {
    const child = children[i]
    const isLastChild = i === children.length - 1
    const childVarsDisplay = child.variables.length > 0 ? c.dim(` via ${child.variables.join(', ')}`) : ''

    renderTreeNode(
      child.id,
      prefix + childPrefix,
      isLastChild,
      childrenMap,
      nodeMap,
      blockMap,
      rendered,
      c,
      childVarsDisplay
    )
  }