refact: extract tree build a hook

src/components/DocsSidebar/index.tsx

@@ -1,99 +1,25 @@
-import * as R from "ramda"
 import React, { useState } from "react"
 import Tree from "react-treeview"
 import { useStaticQuery, graphql } from "gatsby"
+import useBuildTree from "./useBuildTree"
 import * as SC from "./styles"
 
-interface IFile {
+export interface IFile {
   title: string
   type: "file"
   path: string
 }
 
-interface IFolder {
+export interface IFolder {
   title: string
   type: "folder"
   path: string
   children: IFileOrFolder[]
 }
 
-type IFileOrFolder = IFile | IFolder
+export type IFileOrFolder = IFile | IFolder
 
-const traverse = (
-  [head, ...tail]: string[],
-  basePath = "/docs"
-): IFileOrFolder => {
-  const path = basePath + "/" + head
-  const isFile = !tail.length
-  if (isFile) {
-    // probably not more than one dot
-    const [name] = head.split(".")
-    return {
-      title: name,
-      type: "file",
-      path,
-    }
-  }
-  return {
-    title: head,
-    type: "folder",
-    path,
-    children: [traverse(tail, path)],
-  }
-}
-
-const generateFolder = ({
-  title,
-  path,
-  targets,
-}: {
-  title: IFolder["title"]
-  path: IFile["path"]
-  targets: IFolder[]
-}): IFolder => {
-  const children = join(R.chain(target => target.children, targets))
-
-  return {
-    title,
-    type: "folder",
-    path,
-    children,
-  }
-}
-
-const generateFile = ({
-  title,
-  path,
-}: {
-  title: IFile["title"]
-  path: IFile["path"]
-}): IFile => {
-  return {
-    title,
-    path,
-    type: "file",
-  }
-}
-
-const join = ([head, ...tail]: IFileOrFolder[]): IFileOrFolder[] => {
-  if (!head) return []
-
-  const [similarFs, remaining] = R.partition(
-    obj => obj.title === head.title && obj.type === head.type,
-    tail
-  )
-  const targets = [head, ...similarFs]
-  const { title, path } = head
-
-  const current =
-    head.type === "folder"
-      ? generateFolder({ title, path, targets: targets as IFolder[] })
-      : generateFile({ title, path })
-
-  return [current, ...join(remaining)]
-}
-
-interface IFileQuery {
+export interface IFileQuery {
   node: {
     relativePath: string
     childMarkdownRemark: {
@@ -105,7 +31,7 @@ interface IFileQuery {
   }
 }
 
-interface IAllDocsQuery {
+export interface IAllDocsQuery {
   allFile: {
     edges: IFileQuery[]
   }
@@ -160,17 +86,11 @@ function Folder({ item }: { item: IFolder }) {
 
 const DocsSidebar = () => {
   const docs = useStaticQuery<IAllDocsQuery>(ALL_DOCS)
-
-  const objects = docs.allFile.edges.map(({ node: file }: IFileQuery) =>
-    traverse(file.relativePath.split("/"))
-  )
-  const results = join(objects)
-
-  console.log(results)
+  const tree = useBuildTree(docs)
 
   return (
     <SC.DocsSidebarWrapper>
-      {results.map(node => plantTree(node))}
+      {tree.map(node => plantTree(node))}
     </SC.DocsSidebarWrapper>
   )
 }

src/components/DocsSidebar/useBuildTree.tsx

@@ -0,0 +1,90 @@
+import * as R from "ramda"
+import {
+  IFileOrFolder,
+  IFile,
+  IFolder,
+  IAllDocsQuery,
+  IFileQuery,
+} from "./index"
+
+const traverse = (
+  [head, ...tail]: string[],
+  basePath = "/docs"
+): IFileOrFolder => {
+  const path = basePath + "/" + head
+  const isFile = !tail.length
+  if (isFile) {
+    // probably not more than one dot
+    const [name] = head.split(".")
+    return {
+      title: name,
+      type: "file",
+      path,
+    }
+  }
+  return {
+    title: head,
+    type: "folder",
+    path,
+    children: [traverse(tail, path)],
+  }
+}
+
+const generateFolder = ({
+  title,
+  path,
+  targets,
+}: {
+  title: IFolder["title"]
+  path: IFile["path"]
+  targets: IFolder[]
+}): IFolder => {
+  const children = join(R.chain(target => target.children, targets))
+
+  return {
+    title,
+    type: "folder",
+    path,
+    children,
+  }
+}
+
+const generateFile = ({
+  title,
+  path,
+}: {
+  title: IFile["title"]
+  path: IFile["path"]
+}): IFile => {
+  return {
+    title,
+    path,
+    type: "file",
+  }
+}
+
+const join = ([head, ...tail]: IFileOrFolder[]): IFileOrFolder[] => {
+  if (!head) return []
+
+  const [similarFs, remaining] = R.partition(
+    obj => obj.title === head.title && obj.type === head.type,
+    tail
+  )
+  const targets = [head, ...similarFs]
+  const { title, path } = head
+
+  const current =
+    head.type === "folder"
+      ? generateFolder({ title, path, targets: targets as IFolder[] })
+      : generateFile({ title, path })
+
+  return [current, ...join(remaining)]
+}
+
+export default function useBuildTree(docs: IAllDocsQuery) {
+  const objects = docs.allFile.edges.map(({ node: file }: IFileQuery) =>
+    traverse(file.relativePath.split("/"))
+  )
+
+  return join(objects)
+}