fix orderedTextDepart getter

src/store/modules/library.js

@@ -15,7 +15,7 @@ export default {
   state: {
     trees: {},
     randomNodes: undefined,
-    nodebook: undefined,
+    nodebook: [],
 
     // LibraryOptions options
     tagsOptions: [],
@@ -219,20 +219,20 @@ export default {
 
     nodesDepartsOptions: (state, getters, rootState) => {
       const departIds = rootState.ids.depart
-      if (departIds === undefined || rootState.nodes[departIds[0]] === undefined) return
-      return departIds.map(id => {
-        const text = rootState.nodes[id]
-        const firstAuthor = text.authors !== null ? text.authors[0].name : 'Pad de noms'
+      if (departIds === undefined) return
+      const nodes = departIds.map(id => rootState.nodes[id])
+      if (nodes.some(node => node === undefined)) return
+      return nodes.map(node => {
+        const firstAuthor = node.authors !== null ? node.authors[0].name : 'Pad de noms'
         return {
-          text: `${firstAuthor}, ${text.title} (${id})`,
-          value: id
+          text: `${firstAuthor}, ${node.title} (${node.id})`,
+          value: node.id
         }
       })
     },
 
     // Library
     nodebook: (state, getters, rootState) => {
-      if (!state.nodebook) return []
       return state.nodebook.map(([parentId, ...childrenIds]) => {
         return {
           parent: rootState.nodes[parentId],