From ef228254b3fbe8625431cc5f74b453904554d99b Mon Sep 17 00:00:00 2001
From: MrTuxedo <dev@based.consulting>
Date: Sat, 22 Apr 2023 11:38:11 -0700
Subject: [PATCH] handle observable errors

---
 package-lock.json |  8 ++++++++
 package.json      |  2 ++
 src/blockchain.ts | 14 +++++++++-----
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 10cdddd..a6c522a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,10 +12,12 @@
         "discord.js": "^14.9.0",
         "dotenv": "^16.0.3",
         "ethers": "^6.3.0",
+        "lodash": "^4.17.21",
         "redis": "^4.6.5",
         "rxjs": "^7.8.0"
       },
       "devDependencies": {
+        "@types/lodash": "^4.14.194",
         "typescript": "^4.9.5"
       }
     },
@@ -197,6 +199,12 @@
       "resolved": "https://registry.npmjs.org/@tokenizer/token/-/token-0.3.0.tgz",
       "integrity": "sha512-OvjF+z51L3ov0OyAU0duzsYuvO01PH7x4t6DJx+guahgTnBHkhJdG7soQeTSFLWN3efnHyibZ4Z8l2EuWwJN3A=="
     },
+    "node_modules/@types/lodash": {
+      "version": "4.14.194",
+      "resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.194.tgz",
+      "integrity": "sha512-r22s9tAS7imvBt2lyHC9B8AGwWnXaYb1tY09oyLkXDs4vArpYJzw09nj8MLx5VfciBPGIb+ZwG0ssYnEPJxn/g==",
+      "dev": true
+    },
     "node_modules/@types/node": {
       "version": "18.15.11",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-18.15.11.tgz",
diff --git a/package.json b/package.json
index 2228a04..3935d3b 100644
--- a/package.json
+++ b/package.json
@@ -14,10 +14,12 @@
     "discord.js": "^14.9.0",
     "dotenv": "^16.0.3",
     "ethers": "^6.3.0",
+    "lodash": "^4.17.21",
     "redis": "^4.6.5",
     "rxjs": "^7.8.0"
   },
   "devDependencies": {
+    "@types/lodash": "^4.14.194",
     "typescript": "^4.9.5"
   }
 }
diff --git a/src/blockchain.ts b/src/blockchain.ts
index 01de37c..0b471c4 100644
--- a/src/blockchain.ts
+++ b/src/blockchain.ts
@@ -1,7 +1,8 @@
 import 'dotenv/config.js';
 import { WebSocketProvider, formatUnits } from 'ethers';
-import { Observable } from 'rxjs';
-import { map, scan } from 'rxjs/operators';
+import { sortBy } from 'lodash';
+import { Observable, throwError } from 'rxjs';
+import { catchError, map, scan, retry } from 'rxjs/operators';
 
 import { GasPrices } from '../types/gasPrices';
 
@@ -16,13 +17,14 @@ const blockGasPricesObservable = new Observable<GasPrices>((observer) => {
 
       if (!block) throw new Error(`Error fetching block! ${blockNumber}`);
 
-      const gasPrices = block.prefetchedTransactions.map((tx) => tx.gasPrice).sort();
+      const gasPrices = sortBy(block.prefetchedTransactions, ['gasPrice']).map(x => x.gasPrice);
       const fast = Number(formatUnits(gasPrices[Math.floor(gasPrices.length * 0.9)], "gwei"));
       const average = Number(formatUnits(gasPrices[Math.floor(gasPrices.length / 2)], "gwei"));
       const slow = Number(formatUnits(gasPrices[Math.floor(gasPrices.length * 0.05)], "gwei"));
 
       // Log averages every 10 blocks
-      if (blockNumber % 10 == 0) console.log(`Found new block data for ${blockNumber}! Base average transaction cost: ${slow} Gwei`)
+      if (blockNumber % 10 == 0) console.log(`Found new block data for ${blockNumber}!
+      Gas price spreads: ⚡ ${fast.toFixed(2)} ⦚⦚ 🚶 ${average.toFixed(2)} ⦚⦚ 🐢 ${slow.toFixed(2)} Gwei`)
 
       observer.next({ fast, average, slow } as GasPrices);
     } catch (error) {
@@ -46,7 +48,9 @@ const averageGasPricesObservable = blockGasPricesObservable.pipe(
       average: Math.round(average / blocks.length),
       slow: Math.round(slow / blocks.length),
     } as GasPrices;
-  })
+  }),
+  catchError(err => throwError(() => new Error(err))),
+  retry(2)
 );
 
 export { averageGasPricesObservable };
\ No newline at end of file