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

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