refactor: simplify tree class + add typing

app/src/components/RecursiveListGroup.vue

@@ -1,9 +1,9 @@
 <script setup lang="ts">
-import type { Obj } from '@/types/commons'
+import type { TreeChildNode, AnyTreeNode } from '@/helpers/data/tree'
 
 const props = withDefaults(
   defineProps<{
-    tree: Obj
+    tree: AnyTreeNode
     flush?: boolean
     last?: boolean
     toggleText?: string
@@ -16,10 +16,14 @@ const props = withDefaults(
 )
 
 defineSlots<{
-  default: (props: any) => any
+  default: (props: {
+    [K in keyof TreeChildNode as TreeChildNode[K] extends Function
+      ? never
+      : K]: TreeChildNode[K]
+  }) => any
 }>()
 
-function getClasses(node: Obj, i: number) {
+function getClasses(node: AnyTreeNode, i: number) {
   const children = node.height > 0
   const opened = children && node.data?.opened
   const last =

app/src/helpers/data/tree.ts

@@ -1,15 +1,23 @@
+import type { RouteLocationRaw } from 'vue-router'
+
+type TreeNodeData = {
+  name: string
+  parent: string | null
+  to: RouteLocationRaw
+  opened: boolean
+}
+
 /**
  * A Node that can have a parent and children.
  */
-export class Node {
-  constructor(data) {
-    this.data = data
-    this.depth = 0
-    this.height = 0
-    this.parent = null
-    // this.id = null
-    // this.children = null
-  }
+class TreeNode {
+  data: TreeNodeData | null = null
+  depth: number = 0
+  height: number = 0
+  parent: AnyTreeNode | null = null
+  id: string = 'root'
+  children: TreeChildNode[] = []
+  _remove: boolean = false
 
   /**
    * Invokes the specified `callback` for this node and each descendant in pre-order
@@ -18,17 +26,17 @@ export class Node {
    * The specified function is passed the current descendant, the zero-based traversal
    * index, and this node.
    * Code taken and adapted from d3.js https://github.com/d3/d3-hierarchy/blob/main/src/hierarchy/eachBefore.js.
-   *
-   * @param {function} callback
-   * @return {Object}
    */
-  eachBefore(callback) {
-    const nodes = []
+  eachBefore(
+    callback: (node: AnyTreeNode, index: number, root: TreeRootNode) => void,
+  ) {
+    const root = this as TreeRootNode
+    const nodes: AnyTreeNode[] = []
     let index = -1
-    let node = this
+    let node: AnyTreeNode | undefined = root
 
     while (node) {
-      callback(node, ++index, this)
+      callback(node, ++index, root)
       if (node.children) {
         nodes.push(...node.children)
       }
@@ -45,14 +53,14 @@ export class Node {
    * The specified function is passed the current descendant, the zero-based traversal
    * index, and this node.
    * Code taken and adapted from d3.js https://github.com/d3/d3-hierarchy/blob/main/src/hierarchy/eachAfter.js.
-   *
-   * @param {function} callback
-   * @return {Object}
    */
-  eachAfter(callback) {
-    const nodes = []
-    const next = []
-    let node = this
+  eachAfter(
+    callback: (node: AnyTreeNode, index: number, root: TreeRootNode) => void,
+  ) {
+    const root = this as TreeRootNode
+    const nodes: AnyTreeNode[] = []
+    const next: AnyTreeNode[] = []
+    let node: AnyTreeNode | undefined = root
 
     while (node) {
       next.push(node)
@@ -64,132 +72,113 @@ export class Node {
 
     let index = 0
     for (let i = next.length - 1; i >= 0; i--) {
-      callback(next[i], index++, this)
+      callback(next[i], index++, root)
     }
 
-    return this
+    return root
   }
 
   /**
    * Returns a deep copied and filtered tree of itself.
    * Specified filter function is passed each nodes in post-order traversal and must
    * return `true` or `false` like a regular filter function.
-   *
-   * @param {Function} callback - filter callback function to invoke on each nodes
-   * @param {Object} args
-   * @param {String} [args.idKey='name'] - the key name where we can find the node identity.
-   * @param {String} [args.parentIdKey='name'] - the key name where we can find the parent identity.
-   * @return {Node}
    */
-  filter(callback) {
+  filter(
+    callback: (node: AnyTreeNode, index: number, root: TreeRootNode) => boolean,
+  ) {
+    const root = this as TreeRootNode
     // Duplicates this tree and iter on nodes from leaves to root (post-order traversal)
-    return hierarchy(this).eachAfter((node, i) => {
+    return hierarchy(root).eachAfter((node, i) => {
       // Since we create a new hierarchy from another, nodes's `data` contains the
       // whole dupplicated node. Overwrite node's `data` by node's original `data`.
-      node.data = node.data.data
 
       if (node.children) {
         // Removed flagged children
-        node.children = node.children.filter((child) => !child.remove)
-        if (!node.children.length) delete node.children
+        node.children = node.children.filter((child) => !child._remove)
       }
 
       // Perform filter callback on non-root nodes
-      const match = node.data ? callback(node, i, this) : true
+      const match =
+        node instanceof TreeChildNode ? callback(node, i, root) : true
       // Flag node if there's no match in node nor in its children
-      if (!match && !node.children) {
-        node.remove = true
+      if (!match && !node.children.length) {
+        node._remove = true
       }
     })
   }
 }
 
+export class TreeRootNode extends TreeNode {
+  data: null = null
+  parent: null = null
+  id: 'root' = 'root'
+}
+
+export class TreeChildNode extends TreeNode {
+  data: TreeNodeData
+  parent: AnyTreeNode
+  id: string
+
+  constructor(data: TreeNodeData, parent: AnyTreeNode) {
+    super()
+    this.data = data
+    this.parent = parent
+    this.id = data.name
+  }
+}
+
+export type AnyTreeNode = TreeRootNode | TreeChildNode
 /**
  * Generates a new hierarchy from the specified tabular `dataset`.
  * The specified `dataset` must be an array of objects that contains at least a
  * `name` property and an optional `parent` property referencing its parent `name`.
  * Code taken and adapted from d3.js https://github.com/d3/d3-hierarchy/blob/main/src/stratify.js#L16.
- *
- * @param {Array} dataset
- * @param {Object} args
- * @param {String} [args.idKey='name'] - the key name where we can find the node identity.
- * @param {String} [args.parentIdKey='name'] - the key name where we can find the parent identity.
- * @return {Node}
  */
-export function stratify(
-  dataset,
-  { idKey = 'name', parentIdKey = 'parent' } = {},
-) {
-  const root = new Node(null, true)
-  root.children = []
-  const nodesMap = new Map()
+export function stratify(dataset: TreeNodeData[]) {
+  const root = new TreeRootNode()
+  const nodesMap: Map<TreeChildNode['id'], TreeChildNode> = new Map()
 
   // Creates all nodes that will be arranged in a hierarchy
-  const nodes = dataset.map((d) => {
-    const node = new Node(d)
-    node.id = d[idKey]
+  dataset.map((d) => {
+    const parent = d.parent ? nodesMap.get(d.parent) || root : root
+    const node = new TreeChildNode(d, parent)
+    parent.children.push(node)
     nodesMap.set(node.id, node)
-    if (d[parentIdKey]) {
-      node.parent = d[parentIdKey]
-    }
     return node
   })
 
-  // Build a hierarchy from nodes
-  nodes.forEach((node, i) => {
-    const parentId = node.parent
-    if (parentId) {
-      const parent = nodesMap.get(parentId)
-      if (!parent) throw new Error('Missing parent node: ' + parentId)
-      if (parent.children) parent.children.push(node)
-      else parent.children = [node]
-      node.parent = parent
-    } else {
-      node.parent = root
-      root.children.push(node)
-    }
-  })
-
   root.eachBefore((node) => {
     // Compute node depth
     if (node.parent) {
       node.depth = node.parent.depth + 1
       // Remove parent key if parent is root (node with no data)
-      if (!node.parent.data) delete node.parent
     }
     computeNodeHeight(node)
   })
+
   return root
 }
 
 /**
  * Constructs a root node from the specified hierarchical `data`.
  * The specified `data` must be an object representing the root node and its children.
- * If given a `Node` object this will return a deep copy of it.
+ * If given a `TreeRootNode` object this will return a deep copy of it.
  * Code taken and adapted from d3.js https://github.com/d3/d3-hierarchy/blob/main/src/hierarchy/index.js#L15.
  *
- * @param {Node|Object} data - object representing a root node (a simple { id, children } object or a `Node`)
- * @return {Node}
+ * @param data - object representing a root node (a simple { id, children } object or a `TreeNode`)
  */
-export function hierarchy(data) {
-  const root = new Node(data)
-  const nodes = []
-  let node = root
-
-  while (node) {
-    if (node.data.children) {
-      node.children = node.data.children.map((child_) => {
-        const child = new Node(child_)
-        child.id = child_.id
-        child.parent = node === root ? null : node
-        child.depth = node.depth + 1
-        nodes.push(child)
-        return child
-      })
-    }
-    node = nodes.pop()
+export function hierarchy(data: TreeRootNode) {
+  function deepCopyNodes(nodes: TreeChildNode[], parent: AnyTreeNode) {
+    return nodes.map((node) => {
+      const copy = new TreeChildNode(node.data, parent)
+      copy.depth = parent.depth + 1
+      copy.children = deepCopyNodes(node.children, copy)
+      return copy
+    })
   }
 
+  const root = new TreeRootNode()
+  root.children = deepCopyNodes(data.children, root)
   root.eachBefore(computeNodeHeight)
   return root
 }
@@ -197,13 +186,12 @@ export function hierarchy(data) {
 /**
  * Compute the node height by iterating on parents
  * Code taken from d3.js https://github.com/d3/d3-hierarchy/blob/main/src/hierarchy/index.js#L62.
- *
- * @param {Node} node
  */
-function computeNodeHeight(node) {
+function computeNodeHeight(node: TreeNode) {
+  let node_: TreeNode | null = node
   let height = 0
   do {
-    node.height = height
-    node = node.parent
-  } while (node && node.height < ++height)
+    node_.height = height
+    node_ = node_.parent
+  } while (node_ && node_.height < ++height)
 }

app/src/views/domain/DomainList.vue

@@ -3,6 +3,7 @@ import { useStoreGetters } from '@/store/utils'
 import { computed, ref } from 'vue'
 
 import RecursiveListGroup from '@/components/RecursiveListGroup.vue'
+import type { TreeRootNode } from '@/helpers/data/tree'
 
 const { domains, mainDomain, domainsTree } = useStoreGetters()
 
@@ -11,12 +12,13 @@ const search = ref('')
 
 const tree = computed(() => {
   // FIXME rm ts type when moved to pinia or else
-  if (!domainsTree.value) return
+  const tree = domainsTree.value as TreeRootNode | undefined
+  if (!tree) return
   const search_ = search.value.toLowerCase()
   if (search_) {
-    return domainsTree.value.filter((node) => node.id.includes(search_))
+    return tree.filter((node) => node.id.includes(search_))
   }
-  return domainsTree.value
+  return tree
 })
 
 const hasFilteredItems = computed(() => {
@@ -42,6 +44,7 @@ const hasFilteredItems = computed(() => {
     </template>
 
     <RecursiveListGroup
+      v-if="tree"
       :tree="tree"
       :toggle-text="$t('domain.toggle_subdomains')"
       class="mb-5"
@@ -52,9 +55,7 @@ const hasFilteredItems = computed(() => {
           <h5 class="me-3">
             <BLink :to="data.to" class="text-body text-decoration-none">
               <span class="fw-bold">
-                {{
-                  data.name.replace(parent?.data ? parent.data.name : null, '')
-                }}
+                {{ data.name.replace(parent.data?.name ?? '', '') }}
               </span>
               <span v-if="parent?.data" class="text-secondary">
                 {{ parent.data.name }}