feat(renderer): add file info renderer

Implements a new renderer that appends file metadata (size, modification
time, permissions, type) to item labels. Supports relative time display,
field selection, and optional colorization based on file type.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: lambdalisue

builtin/renderer/file_info.ts

@@ -0,0 +1,211 @@
+import { format } from "@std/fmt/bytes";
+import { relative } from "@std/path/relative";
+
+import { defineRenderer, type Renderer } from "../../renderer.ts";
+
+type Detail = {
+  path: string;
+};
+
+export type FileInfoOptions = {
+  /**
+   * Which file information to display.
+   * @default ["size", "modified"]
+   */
+  fields?: Array<"size" | "modified" | "permissions" | "type">;
+
+  /**
+   * Whether to show relative timestamps (e.g., "2 hours ago").
+   * @default true
+   */
+  relativeTime?: boolean;
+
+  /**
+   * Width of each field in characters.
+   * @default { size: 8, modified: 16, permissions: 10, type: 4 }
+   */
+  fieldWidths?: {
+    size?: number;
+    modified?: number;
+    permissions?: number;
+    type?: number;
+  };
+
+  /**
+   * Whether to colorize output (using ANSI codes).
+   * @default false
+   */
+  colorize?: boolean;
+};
+
+/**
+ * Creates a Renderer that appends file information to item labels.
+ *
+ * This Renderer adds file metadata such as size, modification time,
+ * permissions, and file type to each item's label in a formatted manner.
+ *
+ * @param options - Options to customize file info display.
+ * @returns A Renderer that adds file information to item labels.
+ */
+export function fileInfo(
+  options: Readonly<FileInfoOptions> = {},
+): Renderer<Detail> {
+  const fields = options.fields ?? ["size", "modified"];
+  const relativeTime = options.relativeTime ?? true;
+  const fieldWidths = {
+    size: 8,
+    modified: 16,
+    permissions: 10,
+    type: 4,
+    ...options.fieldWidths,
+  };
+  const colorize = options.colorize ?? false;
+
+  return defineRenderer(async (_denops, { items }) => {
+    // Process items in parallel
+    await Promise.all(
+      items.map(async (item) => {
+        const { path } = item.detail;
+        const parts: string[] = [];
+
+        try {
+          // Get file stats
+          const stat = await Deno.stat(path);
+
+          // Add requested fields
+          for (const field of fields) {
+            switch (field) {
+              case "size": {
+                const sizeStr = stat.isFile
+                  ? format(stat.size, { minimumFractionDigits: 0 })
+                  : stat.isDirectory
+                  ? "-"
+                  : "0B";
+                parts.push(sizeStr.padStart(fieldWidths.size));
+                break;
+              }
+
+              case "modified": {
+                const mtime = stat.mtime;
+                let timeStr: string;
+                if (mtime && relativeTime) {
+                  timeStr = formatRelativeTime(mtime);
+                } else if (mtime) {
+                  timeStr = formatDate(mtime);
+                } else {
+                  timeStr = "-";
+                }
+                parts.push(timeStr.padEnd(fieldWidths.modified));
+                break;
+              }
+
+              case "permissions": {
+                const permsStr = formatPermissions(stat.mode);
+                parts.push(permsStr.padEnd(fieldWidths.permissions));
+                break;
+              }
+
+              case "type": {
+                const typeStr = stat.isDirectory
+                  ? "dir"
+                  : stat.isFile
+                  ? "file"
+                  : stat.isSymlink
+                  ? "link"
+                  : "other";
+                parts.push(typeStr.padEnd(fieldWidths.type));
+                break;
+              }
+            }
+          }
+
+          // Combine parts and append to label
+          const info = parts.join(" ");
+          if (colorize) {
+            // Add color based on file type
+            if (stat.isDirectory) {
+              item.label = `${item.label}  \x1b[34m${info}\x1b[0m`;
+            } else if (stat.isSymlink) {
+              item.label = `${item.label}  \x1b[36m${info}\x1b[0m`;
+            } else if ((stat.mode ?? 0) & 0o111) {
+              // Executable
+              item.label = `${item.label}  \x1b[32m${info}\x1b[0m`;
+            } else {
+              item.label = `${item.label}  \x1b[90m${info}\x1b[0m`;
+            }
+          } else {
+            item.label = `${item.label}  ${info}`;
+          }
+        } catch {
+          // If stat fails, add placeholder
+          const placeholder = fields.map((field) => {
+            const width = fieldWidths[field as keyof typeof fieldWidths] ?? 10;
+            return "-".padEnd(width);
+          }).join(" ");
+          item.label = `${item.label}  ${placeholder}`;
+        }
+      }),
+    );
+  });
+}
+
+/**
+ * Formats a date to a relative time string.
+ */
+function formatRelativeTime(date: Date): string {
+  const now = new Date();
+  const diff = now.getTime() - date.getTime();
+  const seconds = Math.floor(diff / 1000);
+  const minutes = Math.floor(seconds / 60);
+  const hours = Math.floor(minutes / 60);
+  const days = Math.floor(hours / 24);
+  const months = Math.floor(days / 30);
+  const years = Math.floor(days / 365);
+
+  if (years > 0) {
+    return `${years}y ago`;
+  } else if (months > 0) {
+    return `${months}mo ago`;
+  } else if (days > 0) {
+    return `${days}d ago`;
+  } else if (hours > 0) {
+    return `${hours}h ago`;
+  } else if (minutes > 0) {
+    return `${minutes}m ago`;
+  } else {
+    return "just now";
+  }
+}
+
+/**
+ * Formats a date to a standard string.
+ */
+function formatDate(date: Date): string {
+  const year = date.getFullYear();
+  const month = String(date.getMonth() + 1).padStart(2, "0");
+  const day = String(date.getDate()).padStart(2, "0");
+  const hour = String(date.getHours()).padStart(2, "0");
+  const minute = String(date.getMinutes()).padStart(2, "0");
+  return `${year}-${month}-${day} ${hour}:${minute}`;
+}
+
+/**
+ * Formats file permissions to a Unix-style string.
+ */
+function formatPermissions(mode: number | null): string {
+  if (mode === null) {
+    return "---------";
+  }
+
+  const perms = [];
+  const types = ["---", "--x", "-w-", "-wx", "r--", "r-x", "rw-", "rwx"];
+
+  // User permissions
+  perms.push(types[(mode >> 6) & 7]);
+  // Group permissions
+  perms.push(types[(mode >> 3) & 7]);
+  // Other permissions
+  perms.push(types[mode & 7]);
+
+  return perms.join("");
+}

builtin/renderer/mod.ts

@@ -1,5 +1,6 @@
 // This file is generated by gen-mod.ts
 export * from "./absolute_path.ts";
+export * from "./file_info.ts";
 export * from "./helptag.ts";
 export * from "./nerdfont.ts";
 export * from "./noop.ts";