get balance of previous transaction to avoid decay calculation

frontend/src/components/DecayInformations/DecayInformation-Decay.vue

@@ -13,7 +13,7 @@
       </b-col>
       <b-col cols="6">
         <div>
-          {{ (Number(balance) - Number(decay)) | GDD }}
+          {{ previousBookedBalance | GDD }}
           {{ decay | GDD }} {{ $t('math.equal') }}
           <b>{{ balance | GDD }}</b>
         </div>
@@ -33,6 +33,10 @@ export default {
       type: String,
       required: true,
     },
+    previousBookedBalance: {
+      type: String,
+      required: true,
+    },
   },
 }
 </script>

frontend/src/components/GddTransactionList.vue

@@ -15,7 +15,11 @@
       <div v-for="({ id, typeId }, index) in transactions" :key="id">
         <transaction-list-item :typeId="typeId" class="pointer">
           <template #DECAY>
-            <transaction-decay class="list-group-item" v-bind="transactions[index]" />
+            <transaction-decay
+              class="list-group-item"
+              v-bind="transactions[index]"
+              :previousBookedBalance="previousBookedBalance(index)"
+            />
           </template>
 
           <template #SEND>
@@ -110,6 +114,10 @@ export default {
       })
       window.scrollTo(0, 0)
     },
+    previousBookedBalance(idx) {
+      if (this.transactions[idx + 1]) return this.transactions[idx + 1].balance
+      return 0
+    },
   },
   watch: {
     currentPage() {

frontend/src/components/Transactions/TransactionDecay.vue

@@ -21,7 +21,11 @@
       </div>
 
       <b-collapse class="pb-4 pt-5" v-model="visible">
-        <decay-information-decay :balance="balance" :decay="decay.decay" />
+        <decay-information-decay
+          :balance="balance"
+          :decay="decay.decay"
+          :previousBookedBalance="previousBookedBalance"
+        />
       </b-collapse>
     </div>
   </div>
@@ -53,6 +57,10 @@ export default {
       type: Object,
       required: true,
     },
+    previousBookedBalance: {
+      type: String,
+      required: true,
+    },
   },
   data() {
     return {