refactor: extract shared utilities (isMarkdownFile, isPlainObject, resolveSymlink) (#33)

src/features/claude-code-agent-loader/loader.ts

@@ -3,6 +3,7 @@ import { homedir } from "os"
 import { join, basename } from "path"
 import type { AgentConfig } from "@opencode-ai/sdk"
 import { parseFrontmatter } from "../../shared/frontmatter"
+import { isMarkdownFile } from "../../shared/file-utils"
 import type { AgentScope, AgentFrontmatter, LoadedAgent } from "./types"
 
 function parseToolsConfig(toolsStr?: string): Record<string, boolean> | undefined {
@@ -18,10 +19,6 @@ function parseToolsConfig(toolsStr?: string): Record<string, boolean> | undefine
   return result
 }
 
-function isMarkdownFile(entry: { name: string; isFile: () => boolean }): boolean {
-  return !entry.name.startsWith(".") && entry.name.endsWith(".md") && entry.isFile()
-}
-
 function loadAgentsFromDir(agentsDir: string, scope: AgentScope): LoadedAgent[] {
   if (!existsSync(agentsDir)) {
     return []

src/features/claude-code-command-loader/loader.ts

@@ -3,12 +3,9 @@ import { homedir } from "os"
 import { join, basename } from "path"
 import { parseFrontmatter } from "../../shared/frontmatter"
 import { sanitizeModelField } from "../../shared/model-sanitizer"
+import { isMarkdownFile } from "../../shared/file-utils"
 import type { CommandScope, CommandDefinition, CommandFrontmatter, LoadedCommand } from "./types"
 
-function isMarkdownFile(entry: { name: string; isFile: () => boolean }): boolean {
-  return !entry.name.startsWith(".") && entry.name.endsWith(".md") && entry.isFile()
-}
-
 function loadCommandsFromDir(commandsDir: string, scope: CommandScope): LoadedCommand[] {
   if (!existsSync(commandsDir)) {
     return []

src/features/claude-code-skill-loader/loader.ts

@@ -1,8 +1,9 @@
-import { existsSync, readdirSync, readFileSync, lstatSync, readlinkSync } from "fs"
+import { existsSync, readdirSync, readFileSync } from "fs"
 import { homedir } from "os"
-import { join, resolve } from "path"
+import { join } from "path"
 import { parseFrontmatter } from "../../shared/frontmatter"
 import { sanitizeModelField } from "../../shared/model-sanitizer"
+import { resolveSymlink } from "../../shared/file-utils"
 import type { CommandDefinition } from "../claude-code-command-loader/types"
 import type { SkillScope, SkillMetadata, LoadedSkillAsCommand } from "./types"
 
@@ -21,14 +22,7 @@ function loadSkillsFromDir(skillsDir: string, scope: SkillScope): LoadedSkillAsC
 
     if (!entry.isDirectory() && !entry.isSymbolicLink()) continue
 
-    let resolvedPath = skillPath
-    try {
-      if (lstatSync(skillPath, { throwIfNoEntry: false })?.isSymbolicLink()) {
-        resolvedPath = resolve(skillPath, "..", readlinkSync(skillPath))
-      }
-    } catch {
-      continue
-    }
+    const resolvedPath = resolveSymlink(skillPath)
 
     const skillMdPath = join(resolvedPath, "SKILL.md")
     if (!existsSync(skillMdPath)) continue

src/shared/deep-merge.ts

@@ -1,7 +1,7 @@
 const DANGEROUS_KEYS = new Set(["__proto__", "constructor", "prototype"]);
 const MAX_DEPTH = 50;
 
-function isPlainObject(value: unknown): value is Record<string, unknown> {
+export function isPlainObject(value: unknown): value is Record<string, unknown> {
   return (
     typeof value === "object" &&
     value !== null &&

src/shared/file-utils.ts

@@ -0,0 +1,26 @@
+import { lstatSync, readlinkSync } from "fs"
+import { resolve } from "path"
+
+export function isMarkdownFile(entry: { name: string; isFile: () => boolean }): boolean {
+  return !entry.name.startsWith(".") && entry.name.endsWith(".md") && entry.isFile()
+}
+
+export function isSymbolicLink(filePath: string): boolean {
+  try {
+    return lstatSync(filePath, { throwIfNoEntry: false })?.isSymbolicLink() ?? false
+  } catch {
+    return false
+  }
+}
+
+export function resolveSymlink(filePath: string): string {
+  try {
+    const stats = lstatSync(filePath, { throwIfNoEntry: false })
+    if (stats?.isSymbolicLink()) {
+      return resolve(filePath, "..", readlinkSync(filePath))
+    }
+    return filePath
+  } catch {
+    return filePath
+  }
+}

src/shared/index.ts

@@ -8,3 +8,4 @@ export * from "./tool-name"
 export * from "./pattern-matcher"
 export * from "./hook-disabled"
 export * from "./deep-merge"
+export * from "./file-utils"

src/shared/snake-case.ts

@@ -1,3 +1,5 @@
+import { isPlainObject } from "./deep-merge"
+
 export function camelToSnake(str: string): string {
   return str.replace(/[A-Z]/g, (letter) => `_${letter.toLowerCase()}`)
 }
@@ -6,10 +8,6 @@ export function snakeToCamel(str: string): string {
   return str.replace(/_([a-z])/g, (_, letter) => letter.toUpperCase())
 }
 
-function isPlainObject(value: unknown): value is Record<string, unknown> {
-  return typeof value === "object" && value !== null && !Array.isArray(value)
-}
-
 export function objectToSnakeCase(
   obj: Record<string, unknown>,
   deep: boolean = true

src/tools/skill/tools.ts

@@ -1,9 +1,10 @@
 import { tool } from "@opencode-ai/plugin"
-import { existsSync, readdirSync, lstatSync, readlinkSync, readFileSync } from "fs"
+import { existsSync, readdirSync, readFileSync } from "fs"
 import { homedir } from "os"
-import { join, resolve, basename } from "path"
+import { join, basename } from "path"
 import { z } from "zod/v4"
 import { parseFrontmatter, resolveCommandsInText } from "../../shared"
+import { resolveSymlink } from "../../shared/file-utils"
 import { SkillFrontmatterSchema } from "./types"
 import type { SkillScope, SkillMetadata, SkillInfo, LoadedSkill, SkillFrontmatter } from "./types"
 
@@ -37,15 +38,7 @@ function discoverSkillsFromDir(
     const skillPath = join(skillsDir, entry.name)
 
     if (entry.isDirectory() || entry.isSymbolicLink()) {
-      let resolvedPath = skillPath
-      try {
-        const stats = lstatSync(skillPath, { throwIfNoEntry: false })
-        if (stats?.isSymbolicLink()) {
-          resolvedPath = resolve(skillPath, "..", readlinkSync(skillPath))
-        }
-      } catch {
-        continue
-      }
+      const resolvedPath = resolveSymlink(skillPath)
 
       const skillMdPath = join(resolvedPath, "SKILL.md")
       if (!existsSync(skillMdPath)) continue
@@ -83,18 +76,6 @@ const skillListForDescription = availableSkills
   .map((s) => `- ${s.name}: ${s.description} (${s.scope})`)
   .join("\n")
 
-function resolveSymlink(skillPath: string): string {
-  try {
-    const stats = lstatSync(skillPath, { throwIfNoEntry: false })
-    if (stats?.isSymbolicLink()) {
-      return resolve(skillPath, "..", readlinkSync(skillPath))
-    }
-    return skillPath
-  } catch {
-    return skillPath
-  }
-}
-
 async function parseSkillMd(skillPath: string): Promise<SkillInfo | null> {
   const resolvedPath = resolveSymlink(skillPath)
   const skillMdPath = join(resolvedPath, "SKILL.md")

src/tools/slashcommand/tools.ts

@@ -3,6 +3,7 @@ import { existsSync, readdirSync, readFileSync } from "fs"
 import { homedir } from "os"
 import { join, basename, dirname } from "path"
 import { parseFrontmatter, resolveCommandsInText, resolveFileReferencesInText, sanitizeModelField } from "../../shared"
+import { isMarkdownFile } from "../../shared/file-utils"
 import type { CommandScope, CommandMetadata, CommandInfo } from "./types"
 
 function discoverCommandsFromDir(commandsDir: string, scope: CommandScope): CommandInfo[] {
@@ -14,9 +15,7 @@ function discoverCommandsFromDir(commandsDir: string, scope: CommandScope): Comm
   const commands: CommandInfo[] = []
 
   for (const entry of entries) {
-    if (entry.name.startsWith(".")) continue
-    if (!entry.name.endsWith(".md")) continue
-    if (!entry.isFile()) continue
+    if (!isMarkdownFile(entry)) continue
 
     const commandPath = join(commandsDir, entry.name)
     const commandName = basename(entry.name, ".md")