Add 'try catch' statements to writing disk

'try catch' statement will handle errors like "Directory already
exists". Also, the check of mkdir is located now at the beggining of the
script, reducing the probability of not being able to save the data
queried to subgraph.

scripts/gen_merkle_dist.js

@@ -11,6 +11,13 @@ const endTimeDate = new Date(endTime * 1000).toISOString().slice(0, 10)
 const distribution_path = "distributions/" + endTimeDate
 
 async function main() {
+  try {
+    fs.mkdirSync(distribution_path)
+  } catch (err) {
+    console.error(err)
+    return
+  }
+
   const ongoingRewards = await stakingRewards.getOngoingMekleInput(
     graphqlApi,
     startTime,
@@ -23,27 +30,27 @@ async function main() {
   )
   const merkleDist = stakingRewards.genMerkleDist(merkleInput)
 
-  fs.mkdir(distribution_path, (err) => {
-    if (err) {
-      return console.error(err)
-    }
-  })
-  fs.writeFileSync(
-    distribution_path + "/MerkleInputOngoingRewards.json",
-    JSON.stringify(ongoingRewards, null, 4)
-  )
-  fs.writeFileSync(
-    distribution_path + "/MerkleInputBonusRewards.json",
-    JSON.stringify(bonusRewards, null, 4)
-  )
-  fs.writeFileSync(
-    distribution_path + "/MerkleInputTotalRewards.json",
-    JSON.stringify(merkleInput, null, 4)
-  )
-  fs.writeFileSync(
-    distribution_path + "/MerkleDist.json",
-    JSON.stringify(merkleDist, null, 4)
-  )
+  try{
+    fs.writeFileSync(
+      distribution_path + "/MerkleInputOngoingRewards.json",
+      JSON.stringify(ongoingRewards, null, 4)
+    )
+    fs.writeFileSync(
+      distribution_path + "/MerkleInputBonusRewards.json",
+      JSON.stringify(bonusRewards, null, 4)
+    )
+    fs.writeFileSync(
+      distribution_path + "/MerkleInputTotalRewards.json",
+      JSON.stringify(merkleInput, null, 4)
+    )
+    fs.writeFileSync(
+      distribution_path + "/MerkleDist.json",
+      JSON.stringify(merkleDist, null, 4)
+    )
+  } catch (err) {
+    console.error(err)
+    return
+  }
 
   console.log("Total amount of rewards: ", merkleDist.totalAmount)
 }