refactor(coding-agent): flattened directory structure, eliminated core/ folder

- Eliminated core/ directory (252 files, 23 subdirs → distributed) - Reduced max nesting from 9 levels to 5 levels - Promoted tool subdirs to top level: exa/, lsp/, patch/, task/, web/ - Merged web-scrapers/ + web-search/ into web/{scrapers,search}/ - Flattened modes/interactive/ to modes/ - Split execution/ into: ipy/ (python), exec/ (bash), ssh/ - Renamed ipy/python-*.ts to ipy/*.ts (executor, kernel, etc.) - Flattened cursor/exec-bridge.ts to cursor.ts - Created logical groupings: config/, session/, extensibility/, export/ - Updated all imports across 500+ files
2026-01-23 12:24:47 +01:00
parent 7b5af2dd9f
commit cb5bbbf382
531 changed files with 1316 additions and 1322 deletions
@@ -0,0 +1,721 @@
+/**
+ * Shared utilities and constants for tool renderers.
+ *
+ * Provides consistent formatting, truncation, and display patterns across all
+ * tool renderers to ensure a unified TUI experience.
+ */
+
+import { homedir } from "node:os";
+import type { Theme } from "$c/modes/theme/theme";
+
+// =============================================================================
+// Standardized Display Constants
+// =============================================================================
+
+/** Preview limits for collapsed/expanded views */
+export const PREVIEW_LIMITS = {
+	/** Lines shown in collapsed view */
+	COLLAPSED_LINES: 3,
+	/** Lines shown in expanded view */
+	EXPANDED_LINES: 12,
+	/** Items (files, results) shown in collapsed view */
+	COLLAPSED_ITEMS: 8,
+	/** Output preview lines in collapsed view */
+	OUTPUT_COLLAPSED: 3,
+	/** Output preview lines in expanded view */
+	OUTPUT_EXPANDED: 10,
+} as const;
+
+/** Truncation lengths for different content types */
+export const TRUNCATE_LENGTHS = {
+	/** Short titles, labels */
+	TITLE: 60,
+	/** Medium-length content (messages, previews) */
+	CONTENT: 80,
+	/** Longer content (code, explanations) */
+	LONG: 100,
+	/** Full line content */
+	LINE: 110,
+	/** Very short (task previews, badges) */
+	SHORT: 40,
+} as const;
+
+/** Standard expand hint text */
+export const EXPAND_HINT = "(Ctrl+O for more)";
+
+// =============================================================================
+// Text Truncation Utilities
+// =============================================================================
+
+/**
+ * Truncate text to max length with ellipsis.
+ * The most commonly duplicated utility across renderers.
+ */
+export function truncate(text: string, maxLen: number, ellipsis: string): string {
+	if (text.length <= maxLen) return text;
+	const sliceLen = Math.max(0, maxLen - ellipsis.length);
+	return `${text.slice(0, sliceLen)}${ellipsis}`;
+}
+
+/**
+ * Get first N lines of text as preview, with each line truncated.
+ */
+export function getPreviewLines(text: string, maxLines: number, maxLineLen: number, ellipsis: string): string[] {
+	const lines = text.split("\n").filter((l) => l.trim());
+	return lines.slice(0, maxLines).map((l) => truncate(l.trim(), maxLineLen, ellipsis));
+}
+
+// =============================================================================
+// URL Utilities
+// =============================================================================
+
+/**
+ * Extract domain from URL, stripping www. prefix.
+ */
+export function getDomain(url: string): string {
+	try {
+		const u = new URL(url);
+		return u.hostname.replace(/^www\./, "");
+	} catch {
+		return url;
+	}
+}
+
+// =============================================================================
+// Formatting Utilities
+// =============================================================================
+
+/**
+ * Format byte count for display (e.g., "1.5KB", "2.3MB").
+ */
+export function formatBytes(bytes: number): string {
+	if (bytes < 1024) return `${bytes}B`;
+	if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)}KB`;
+	return `${(bytes / (1024 * 1024)).toFixed(1)}MB`;
+}
+
+/**
+ * Format token count for display (e.g., "1.5k", "25k").
+ */
+export function formatTokens(tokens: number): string {
+	if (tokens >= 1000) {
+		return `${(tokens / 1000).toFixed(1)}k`;
+	}
+	return String(tokens);
+}
+
+/**
+ * Format duration for display (e.g., "500ms", "2.5s", "1.2m").
+ */
+export function formatDuration(ms: number): string {
+	if (ms < 1000) return `${ms}ms`;
+	if (ms < 60000) return `${(ms / 1000).toFixed(1)}s`;
+	return `${(ms / 60000).toFixed(1)}m`;
+}
+
+/**
+ * Format count with pluralized label (e.g., "3 files", "1 error").
+ */
+export function formatCount(label: string, count: number): string {
+	const safeCount = Number.isFinite(count) ? count : 0;
+	return `${safeCount} ${pluralize(label, safeCount)}`;
+}
+
+/**
+ * Format age from seconds to human-readable string.
+ */
+export function formatAge(ageSeconds: number | null | undefined): string {
+	if (!ageSeconds) return "";
+	const mins = Math.floor(ageSeconds / 60);
+	const hours = Math.floor(mins / 60);
+	const days = Math.floor(hours / 24);
+	const weeks = Math.floor(days / 7);
+	const months = Math.floor(days / 30);
+
+	if (months > 0) return `${months}mo ago`;
+	if (weeks > 0) return `${weeks}w ago`;
+	if (days > 0) return `${days}d ago`;
+	if (hours > 0) return `${hours}h ago`;
+	if (mins > 0) return `${mins}m ago`;
+	return "just now";
+}
+
+// =============================================================================
+// Theme Helper Utilities
+// =============================================================================
+
+/**
+ * Get the appropriate status icon with color for a given state.
+ * Standardizes status icon usage across all renderers.
+ */
+export function formatStatusIcon(status: ToolUIStatus, theme: Theme, spinnerFrame?: number): string {
+	switch (status) {
+		case "success":
+			return theme.styledSymbol("status.success", "success");
+		case "error":
+			return theme.styledSymbol("status.error", "error");
+		case "warning":
+			return theme.styledSymbol("status.warning", "warning");
+		case "info":
+			return theme.styledSymbol("status.info", "accent");
+		case "pending":
+			return theme.styledSymbol("status.pending", "muted");
+		case "running":
+			if (spinnerFrame !== undefined) {
+				const frames = theme.spinnerFrames;
+				return frames[spinnerFrame % frames.length];
+			}
+			return theme.styledSymbol("status.running", "accent");
+		case "aborted":
+			return theme.styledSymbol("status.aborted", "error");
+	}
+}
+
+/**
+ * Format the expand hint with proper theming.
+ * Returns empty string if already expanded or there is nothing more to show.
+ */
+export function formatExpandHint(theme: Theme, expanded?: boolean, hasMore?: boolean): string {
+	if (expanded) return "";
+	if (hasMore === false) return "";
+	return theme.fg("dim", wrapBrackets(EXPAND_HINT, theme));
+}
+
+/**
+ * Format a badge like [done] or [failed] with brackets and color.
+ */
+export function formatBadge(label: string, color: ToolUIColor, theme: Theme): string {
+	const left = theme.format.bracketLeft;
+	const right = theme.format.bracketRight;
+	return theme.fg(color, `${left}${label}${right}`);
+}
+
+/**
+ * Build a "more items" suffix line for truncated lists.
+ * Uses consistent wording pattern.
+ */
+export function formatMoreItems(remaining: number, itemType: string, theme: Theme): string {
+	const safeRemaining = Number.isFinite(remaining) ? remaining : 0;
+	return `${theme.format.ellipsis} ${safeRemaining} more ${pluralize(itemType, safeRemaining)}`;
+}
+
+export function formatMeta(meta: string[], theme: Theme): string {
+	return meta.length > 0 ? ` ${theme.fg("muted", meta.join(theme.sep.dot))}` : "";
+}
+
+export function formatScope(scopePath: string | undefined, theme: Theme): string {
+	return scopePath ? ` ${theme.fg("muted", `in ${scopePath}`)}` : "";
+}
+
+export function formatTruncationSuffix(truncated: boolean, theme: Theme): string {
+	return truncated ? theme.fg("warning", " (truncated)") : "";
+}
+
+export function formatErrorMessage(message: string | undefined, theme: Theme): string {
+	const clean = (message ?? "").replace(/^Error:\s*/, "").trim();
+	return `${theme.styledSymbol("status.error", "error")} ${theme.fg("error", `Error: ${clean || "Unknown error"}`)}`;
+}
+
+export function formatEmptyMessage(message: string, theme: Theme): string {
+	return `${theme.styledSymbol("status.warning", "warning")} ${theme.fg("muted", message)}`;
+}
+
+// =============================================================================
+// Tool UI Kit
+// =============================================================================
+
+export type ToolUIStatus = "success" | "error" | "warning" | "info" | "pending" | "running" | "aborted";
+export type ToolUIColor = "success" | "error" | "warning" | "accent" | "muted";
+
+export interface ToolUITitleOptions {
+	bold?: boolean;
+}
+
+// =============================================================================
+// Diagnostic Formatting
+// =============================================================================
+
+export class ToolUIKit {
+	constructor(public theme: Theme) {}
+
+	title(label: string, options?: ToolUITitleOptions): string {
+		const content = options?.bold === false ? label : this.theme.bold(label);
+		return this.theme.fg("toolTitle", content);
+	}
+
+	meta(meta: string[]): string {
+		return formatMeta(meta, this.theme);
+	}
+
+	count(label: string, count: number): string {
+		return formatCount(label, count);
+	}
+
+	moreItems(remaining: number, itemType: string): string {
+		return formatMoreItems(remaining, itemType, this.theme);
+	}
+
+	expandHint(expanded: boolean, hasMore: boolean): string {
+		return formatExpandHint(this.theme, expanded, hasMore);
+	}
+
+	scope(scopePath?: string): string {
+		return formatScope(scopePath, this.theme);
+	}
+
+	truncationSuffix(truncated: boolean): string {
+		return formatTruncationSuffix(truncated, this.theme);
+	}
+
+	errorMessage(message: string | undefined): string {
+		return formatErrorMessage(message, this.theme);
+	}
+
+	emptyMessage(message: string): string {
+		return formatEmptyMessage(message, this.theme);
+	}
+
+	badge(label: string, color: ToolUIColor): string {
+		return formatBadge(label, color, this.theme);
+	}
+
+	statusIcon(status: ToolUIStatus, spinnerFrame?: number): string {
+		return formatStatusIcon(status, this.theme, spinnerFrame);
+	}
+
+	wrapBrackets(text: string): string {
+		return wrapBrackets(text, this.theme);
+	}
+
+	truncate(text: string, maxLen: number): string {
+		return truncate(text, maxLen, this.theme.format.ellipsis);
+	}
+
+	previewLines(text: string, maxLines: number, maxLineLen: number): string[] {
+		return getPreviewLines(text, maxLines, maxLineLen, this.theme.format.ellipsis);
+	}
+
+	formatBytes(bytes: number): string {
+		return formatBytes(bytes);
+	}
+
+	formatTokens(tokens: number): string {
+		return formatTokens(tokens);
+	}
+
+	formatDuration(ms: number): string {
+		return formatDuration(ms);
+	}
+
+	formatAge(ageSeconds: number | null | undefined): string {
+		return formatAge(ageSeconds);
+	}
+
+	formatDiagnostics(
+		diag: { errored: boolean; summary: string; messages: string[] },
+		expanded: boolean,
+		getLangIcon: (filePath: string) => string,
+	): string {
+		return formatDiagnostics(diag, expanded, this.theme, getLangIcon);
+	}
+
+	formatDiffStats(added: number, removed: number, hunks: number): string {
+		return formatDiffStats(added, removed, hunks, this.theme);
+	}
+}
+
+interface ParsedDiagnostic {
+	filePath: string;
+	line: number;
+	col: number;
+	severity: "error" | "warning" | "info" | "hint";
+	source?: string;
+	message: string;
+	code?: string;
+}
+
+function parseDiagnosticMessage(msg: string): ParsedDiagnostic | null {
+	const match = msg.match(/^(.+?):(\d+):(\d+)\s+\[(\w+)\]\s+(?:\[([^\]]+)\]\s+)?(.+?)(?:\s+\(([^)]+)\))?$/);
+	if (!match) return null;
+	return {
+		filePath: match[1],
+		line: parseInt(match[2], 10),
+		col: parseInt(match[3], 10),
+		severity: match[4] as ParsedDiagnostic["severity"],
+		source: match[5],
+		message: match[6],
+		code: match[7],
+	};
+}
+
+export function formatDiagnostics(
+	diag: { errored: boolean; summary: string; messages: string[] },
+	expanded: boolean,
+	theme: Theme,
+	getLangIcon: (filePath: string) => string,
+): string {
+	if (diag.messages.length === 0) return "";
+
+	const byFile = new Map<string, ParsedDiagnostic[]>();
+	const unparsed: string[] = [];
+
+	for (const msg of diag.messages) {
+		const parsed = parseDiagnosticMessage(msg);
+		if (parsed) {
+			const existing = byFile.get(parsed.filePath) ?? [];
+			existing.push(parsed);
+			byFile.set(parsed.filePath, existing);
+		} else {
+			unparsed.push(msg);
+		}
+	}
+
+	const headerIcon = diag.errored
+		? theme.styledSymbol("status.error", "error")
+		: theme.styledSymbol("status.warning", "warning");
+	let output = `\n\n${headerIcon} ${theme.fg("toolTitle", "Diagnostics")} ${theme.fg("dim", `(${diag.summary})`)}`;
+
+	const maxDiags = expanded ? diag.messages.length : 5;
+	let diagsShown = 0;
+
+	const files = Array.from(byFile.entries());
+
+	// Count total diagnostics for "... X more" calculation
+	const totalParsedDiags = files.reduce((sum, [, diags]) => sum + diags.length, 0);
+	const totalDiags = totalParsedDiags + unparsed.length;
+
+	// Helper to check if this is the very last item in the tree
+	const isTreeEnd = (fileIdx: number, diagIdx: number | null, unparsedIdx: number | null): boolean => {
+		const willShowMore = totalDiags > diagsShown + 1;
+		if (willShowMore) return false;
+
+		if (unparsedIdx !== null) {
+			return unparsedIdx === unparsed.length - 1;
+		}
+		if (diagIdx !== null) {
+			const isLastDiagInFile = diagIdx === files[fileIdx][1].length - 1;
+			const isLastFile = fileIdx === files.length - 1;
+			return isLastDiagInFile && isLastFile && unparsed.length === 0;
+		}
+		// File node - never the tree end if it has diagnostics
+		return false;
+	};
+
+	for (let fi = 0; fi < files.length && diagsShown < maxDiags; fi++) {
+		const [filePath, diagnostics] = files[fi];
+		// File is "last" only if no more files AND no unparsed AND we'll show all diags AND no "... X more"
+		const remainingDiagsInFile = diagnostics.length;
+		const remainingDiagsAfter = files.slice(fi + 1).reduce((sum, [, d]) => sum + d.length, 0) + unparsed.length;
+		const willShowAllRemaining = diagsShown + remainingDiagsInFile + remainingDiagsAfter <= maxDiags;
+		const isLastFileNode = fi === files.length - 1 && unparsed.length === 0 && willShowAllRemaining;
+		const fileBranch = isLastFileNode ? theme.tree.last : theme.tree.branch;
+
+		const fileIcon = theme.fg("muted", getLangIcon(filePath));
+		output += `\n ${theme.fg("dim", fileBranch)} ${fileIcon} ${theme.fg("accent", filePath)}`;
+
+		for (let di = 0; di < diagnostics.length && diagsShown < maxDiags; di++) {
+			const d = diagnostics[di];
+			const isLastDiagInFile = di === diagnostics.length - 1;
+			// This is the last visible diag in file if it's actually last OR we're about to hit the limit
+			const atDisplayLimit = diagsShown + 1 >= maxDiags;
+			const isLastVisibleInFile = isLastDiagInFile || atDisplayLimit;
+			// Check if this is the last visible item in the entire tree
+			const isVeryLast = isTreeEnd(fi, di, null);
+			const diagBranch = isLastFileNode
+				? isLastVisibleInFile || isVeryLast
+					? `  ${theme.tree.last}`
+					: `  ${theme.tree.branch}`
+				: isLastVisibleInFile || isVeryLast
+					? `${theme.tree.vertical} ${theme.tree.last}`
+					: `${theme.tree.vertical} ${theme.tree.branch}`;
+
+			const sevIcon =
+				d.severity === "error"
+					? theme.styledSymbol("status.error", "error")
+					: d.severity === "warning"
+						? theme.styledSymbol("status.warning", "warning")
+						: theme.styledSymbol("status.info", "muted");
+			const location = theme.fg("dim", `:${d.line}:${d.col}`);
+			const codeTag = d.code ? theme.fg("dim", ` (${d.code})`) : "";
+			const msgColor = d.severity === "error" ? "error" : d.severity === "warning" ? "warning" : "toolOutput";
+
+			output += `\n ${theme.fg("dim", diagBranch)} ${sevIcon}${location} ${theme.fg(msgColor, d.message)}${codeTag}`;
+			diagsShown++;
+		}
+	}
+
+	for (let ui = 0; ui < unparsed.length && diagsShown < maxDiags; ui++) {
+		const msg = unparsed[ui];
+		const isVeryLast = isTreeEnd(-1, null, ui);
+		const branch = isVeryLast ? theme.tree.last : theme.tree.branch;
+		const color = msg.includes("[error]") ? "error" : msg.includes("[warning]") ? "warning" : "dim";
+		output += `\n ${theme.fg("dim", branch)} ${theme.fg(color, msg)}`;
+		diagsShown++;
+	}
+
+	if (totalDiags > diagsShown) {
+		const remaining = totalDiags - diagsShown;
+		output += `\n ${theme.fg("dim", theme.tree.last)} ${theme.fg(
+			"muted",
+			`${theme.format.ellipsis} ${remaining} more`,
+		)} ${formatExpandHint(theme)}`;
+	}
+
+	return output;
+}
+
+// =============================================================================
+// Diff Utilities
+// =============================================================================
+
+export interface DiffStats {
+	added: number;
+	removed: number;
+	hunks: number;
+	lines: number;
+}
+
+export function getDiffStats(diffText: string): DiffStats {
+	const lines = diffText ? diffText.split("\n") : [];
+	let added = 0;
+	let removed = 0;
+	let hunks = 0;
+	let inHunk = false;
+
+	for (const line of lines) {
+		const isAdded = line.startsWith("+");
+		const isRemoved = line.startsWith("-");
+		const isChange = isAdded || isRemoved;
+
+		if (isAdded) added++;
+		if (isRemoved) removed++;
+
+		if (isChange && !inHunk) {
+			hunks++;
+			inHunk = true;
+		} else if (!isChange) {
+			inHunk = false;
+		}
+	}
+
+	return { added, removed, hunks, lines: lines.length };
+}
+
+export function formatDiffStats(added: number, removed: number, hunks: number, theme: Theme): string {
+	const parts: string[] = [];
+	if (added > 0) parts.push(theme.fg("success", `+${added}`));
+	if (removed > 0) parts.push(theme.fg("error", `-${removed}`));
+	if (hunks > 0) parts.push(theme.fg("dim", `${hunks} hunk${hunks !== 1 ? "s" : ""}`));
+	return parts.join(theme.fg("dim", " / "));
+}
+
+interface DiffSegment {
+	lines: string[];
+	isChange: boolean;
+	isEllipsis: boolean;
+}
+
+function parseDiffSegments(lines: string[]): DiffSegment[] {
+	const segments: DiffSegment[] = [];
+	let current: DiffSegment | null = null;
+
+	for (const line of lines) {
+		const isChange = line.startsWith("+") || line.startsWith("-");
+		const isEllipsis = line.trimStart().startsWith("...");
+
+		if (isEllipsis) {
+			if (current) segments.push(current);
+			segments.push({ lines: [line], isChange: false, isEllipsis: true });
+			current = null;
+		} else if (!current || current.isChange !== isChange) {
+			if (current) segments.push(current);
+			current = { lines: [line], isChange, isEllipsis: false };
+		} else {
+			current.lines.push(line);
+		}
+	}
+
+	if (current) segments.push(current);
+	return segments;
+}
+
+export function truncateDiffByHunk(
+	diffText: string,
+	maxHunks: number,
+	maxLines: number,
+): { text: string; hiddenHunks: number; hiddenLines: number } {
+	const lines = diffText ? diffText.split("\n") : [];
+	const totalStats = getDiffStats(diffText);
+
+	if (lines.length <= maxLines && totalStats.hunks <= maxHunks) {
+		return { text: diffText, hiddenHunks: 0, hiddenLines: 0 };
+	}
+
+	const segments = parseDiffSegments(lines);
+
+	const changeSegments = segments.filter((s) => s.isChange);
+	const changeLineCount = changeSegments.reduce((sum, s) => sum + s.lines.length, 0);
+
+	if (changeLineCount > maxLines) {
+		const kept: string[] = [];
+		let keptHunks = 0;
+
+		for (const seg of segments) {
+			if (seg.isChange) {
+				keptHunks++;
+				if (keptHunks > maxHunks) break;
+			}
+			kept.push(...seg.lines);
+			if (kept.length >= maxLines) break;
+		}
+
+		const keptStats = getDiffStats(kept.join("\n"));
+		return {
+			text: kept.join("\n"),
+			hiddenHunks: Math.max(0, totalStats.hunks - keptStats.hunks),
+			hiddenLines: Math.max(0, lines.length - kept.length),
+		};
+	}
+
+	const contextBudget = maxLines - changeLineCount;
+	const contextSegments = segments.filter((s) => !s.isChange && !s.isEllipsis);
+	const totalContextLines = contextSegments.reduce((sum, s) => sum + s.lines.length, 0);
+
+	const kept: string[] = [];
+	let keptHunks = 0;
+
+	if (totalContextLines <= contextBudget) {
+		for (const seg of segments) {
+			if (seg.isChange) {
+				keptHunks++;
+				if (keptHunks > maxHunks) break;
+			}
+			kept.push(...seg.lines);
+		}
+	} else {
+		const contextRatio = contextSegments.length > 0 ? contextBudget / totalContextLines : 0;
+
+		for (let i = 0; i < segments.length; i++) {
+			const seg = segments[i];
+
+			if (seg.isChange) {
+				keptHunks++;
+				if (keptHunks > maxHunks) break;
+				kept.push(...seg.lines);
+			} else if (seg.isEllipsis) {
+				kept.push(...seg.lines);
+			} else {
+				const allowedLines = Math.max(1, Math.floor(seg.lines.length * contextRatio));
+				const isBeforeChange = segments[i + 1]?.isChange;
+				const isAfterChange = segments[i - 1]?.isChange;
+
+				if (isBeforeChange && isAfterChange) {
+					const half = Math.ceil(allowedLines / 2);
+					if (seg.lines.length > allowedLines) {
+						kept.push(...seg.lines.slice(0, half));
+						kept.push(seg.lines[0].replace(/^(\s*\d*\s*).*/, "$1..."));
+						kept.push(...seg.lines.slice(-half));
+					} else {
+						kept.push(...seg.lines);
+					}
+				} else if (isBeforeChange) {
+					kept.push(...seg.lines.slice(-allowedLines));
+				} else if (isAfterChange) {
+					kept.push(...seg.lines.slice(0, allowedLines));
+				} else {
+					kept.push(...seg.lines.slice(0, Math.min(allowedLines, 2)));
+				}
+			}
+		}
+	}
+
+	const keptStats = getDiffStats(kept.join("\n"));
+	return {
+		text: kept.join("\n"),
+		hiddenHunks: Math.max(0, totalStats.hunks - keptStats.hunks),
+		hiddenLines: Math.max(0, lines.length - kept.length),
+	};
+}
+
+// =============================================================================
+// Path Utilities
+// =============================================================================
+
+export function shortenPath(filePath: string, homeDir?: string): string {
+	const home = homeDir ?? homedir();
+	if (home && filePath.startsWith(home)) {
+		return `~${filePath.slice(home.length)}`;
+	}
+	return filePath;
+}
+
+export function wrapBrackets(text: string, theme: Theme): string {
+	return `${theme.format.bracketLeft}${text}${theme.format.bracketRight}`;
+}
+
+export function replaceTabs(text: string): string {
+	return text.replace(/\t/g, "   ");
+}
+
+function pluralize(label: string, count: number): string {
+	if (count === 1) return label;
+	if (/(?:ch|sh|s|x|z)$/i.test(label)) return `${label}es`;
+	if (/[^aeiou]y$/i.test(label)) return `${label.slice(0, -1)}ies`;
+	return `${label}s`;
+}
+
+// =============================================================================
+// Tree Rendering Utilities
+// =============================================================================
+
+/**
+ * Get the branch character for a tree item.
+ */
+export function getTreeBranch(isLast: boolean, theme: Theme): string {
+	return isLast ? theme.tree.last : theme.tree.branch;
+}
+
+/**
+ * Get the continuation prefix for nested content under a tree item.
+ */
+export function getTreeContinuePrefix(isLast: boolean, theme: Theme): string {
+	return isLast ? "   " : `${theme.tree.vertical}  `;
+}
+
+/**
+ * Render a list of items with tree branches, handling truncation.
+ *
+ * @param items - Full list of items to render
+ * @param expanded - Whether view is expanded
+ * @param maxCollapsed - Max items to show when collapsed
+ * @param renderItem - Function to render a single item
+ * @param itemType - Type name for "more X" message (e.g., "file", "entry")
+ * @param theme - Theme instance
+ * @returns Array of formatted lines
+ */
+export function renderTreeList<T>(
+	items: T[],
+	expanded: boolean,
+	maxCollapsed: number,
+	renderItem: (item: T, branch: string, isLast: boolean, theme: Theme) => string,
+	itemType: string,
+	theme: Theme,
+): string[] {
+	const lines: string[] = [];
+	const maxItems = expanded ? items.length : Math.min(items.length, maxCollapsed);
+
+	for (let i = 0; i < maxItems; i++) {
+		const isLast = i === maxItems - 1 && (expanded || items.length <= maxCollapsed);
+		const branch = getTreeBranch(isLast, theme);
+		lines.push(renderItem(items[i], branch, isLast, theme));
+	}
+
+	if (!expanded && items.length > maxCollapsed) {
+		const remaining = items.length - maxCollapsed;
+		lines.push(
+			` ${theme.fg("dim", theme.tree.last)} ${theme.fg("muted", formatMoreItems(remaining, itemType, theme))}`,
+		);
+	}
+
+	return lines;
+}