fix: strip null bytes from text changed events

.changeset/little-cycles-deny.md

@@ -0,0 +1,5 @@
+---
+"ensindexer": minor
+---
+
+now explicitly strips null bytes from resolver text values rather than relying on ponder's default behavior

apps/ensindexer/src/handlers/Resolver.ts

@@ -6,7 +6,7 @@ import { type Address, Hash, type Hex, hexToBytes } from "viem";
 import { makeSharedEventValues, upsertAccount, upsertResolver } from "@/lib/db-helpers";
 import { decodeTXTData, parseRRSet } from "@/lib/dns-helpers";
 import { makeResolverId } from "@/lib/ids";
-import { hasNullByte, uniq } from "@/lib/lib-helpers";
+import { hasNullByte, stripNullBytes, uniq } from "@/lib/lib-helpers";
 import type { EventWithArgs } from "@/lib/ponder-helpers";
 import { decodeDNSPacketBytes } from "@ensnode/utils/subname-helpers";
 
@@ -187,16 +187,21 @@ export const makeResolverHandlers = ({ pluginName }: { pluginName: PluginName })
         .update(schema.resolver, { id })
         .set({ texts: uniq([...(resolver.texts ?? []), key]) });
 
+      // NOTE: ponder's (viem's) event parsing produces empty string for some TextChanged events
+      // (which is correct) but the subgraph records null for these instances, so we coalesce
+      // falsy strings to null for compatibility
+      // ex: https://etherscan.io/tx/0x7fac4f1802c9b1969311be0412e6f900d531c59155421ff8ce1fda78b87956d0#eventlog
+      //
+      // NOTE: we also must strip null bytes in strings, which are unindexable by Postgres
+      // ex: https://etherscan.io/tx/0x2eb93d872a8f3e4295ea50773c3816dcaea2541f202f650948e8d6efdcbf4599#eventlog
+      const sanitizedValue = !value ? null : stripNullBytes(value) || null;
+
       // log ResolverEvent
       await context.db.insert(schema.textChanged).values({
         ...sharedEventValues(context.network.chainId, event),
         resolverId: id,
         key,
-        // ponder's (viem's) event parsing produces empty string for some TextChanged events
-        // (which is correct) but the subgraph records null for these instances, so we coalesce
-        // falsy strings to null for compatibility
-        // ex: last TextChanged in tx 0x7fac4f1802c9b1969311be0412e6f900d531c59155421ff8ce1fda78b87956d0
-        value: value || null,
+        value: sanitizedValue,
       });
     },
 
@@ -374,6 +379,9 @@ export const makeResolverHandlers = ({ pluginName }: { pluginName: PluginName })
             // https://github.com/mafintosh/dns-packet
             const value = decodeTXTData(answer.data as Buffer[]);
 
+            // note: sanitize value, see `handleTextChanged` for context
+            const sanitizedValue = !value ? null : stripNullBytes(value) || null;
+
             // upsert new key
             await context.db
               .update(schema.resolver, { id })
@@ -384,8 +392,7 @@ export const makeResolverHandlers = ({ pluginName }: { pluginName: PluginName })
               ...sharedEventValues(context.network.chainId, event),
               resolverId: id,
               key,
-              // note: coalesce empty string to null, see `handleTextChanged` for context
-              value: value || null,
+              value: sanitizedValue,
             });
             break;
           }

apps/ensindexer/src/lib/lib-helpers.ts

@@ -1,5 +1,7 @@
 export const uniq = <T>(arr: T[]): T[] => [...new Set(arr)];
 
+export const bigintMax = (...args: bigint[]): bigint => args.reduce((a, b) => (a > b ? a : b));
+
 export const hasNullByte = (value: string) => value.indexOf("\u0000") !== -1;
 
-export const bigintMax = (...args: bigint[]): bigint => args.reduce((a, b) => (a > b ? a : b));
+export const stripNullBytes = (value: string) => value.replaceAll("\u0000", "");

apps/ensindexer/test/lib-helpers.test.ts

@@ -1,4 +1,4 @@
-import { bigintMax, hasNullByte, uniq } from "@/lib/lib-helpers";
+import { bigintMax, hasNullByte, stripNullBytes, uniq } from "@/lib/lib-helpers";
 import { describe, expect, it } from "vitest";
 
 describe("helpers", () => {
@@ -8,6 +8,12 @@ describe("helpers", () => {
     });
   });
 
+  describe("bigintMax", () => {
+    it("should return the maximum bigint value", () => {
+      expect(bigintMax(1n, 2n, 3n)).toBe(3n);
+    });
+  });
+
   describe("hasNullByte", () => {
     it("should return true if the string contains a null byte", () => {
       expect(hasNullByte("hello\u0000world")).toBe(true);
@@ -18,9 +24,11 @@ describe("helpers", () => {
     });
   });
 
-  describe("bigintMax", () => {
-    it("should return the maximum bigint value", () => {
-      expect(bigintMax(1n, 2n, 3n)).toBe(3n);
+  describe("stripNullBytes", () => {
+    it("should remove null bytes", () => {
+      expect(stripNullBytes("hello\u0000world")).toBe("helloworld");
+      expect(stripNullBytes("\0")).toBe("");
+      expect(stripNullBytes("x\0y\0z\0")).toBe("xyz");
     });
   });
 });