fix: fix referral address extraction (#195)

* fix: fix referral address extraction

* Fix tests

* Handle specific error

* Handle case when error is undefined

* Remove decoding and encoding data

* Unde new line deletion

Author: amateima

src/modules/referral/services/service.spec.ts

@@ -8,10 +8,8 @@ describe("ReferralService", () => {
     const moduleRef = await Test.createTestingModule({
       providers: [ReferralService],
     })
-      .useMocker((token) => {
-        if (token === "DepositRepository") {
-          return {};
-        }
+      .useMocker(() => {
+        return {};
       })
       .compile();
 
@@ -45,4 +43,11 @@ describe("ReferralService", () => {
     );
     expect(address).toEqual(undefined);
   });
+
+  it("should not extract referral address if calldata too short", () => {
+    const address = service.extractReferralAddressUsingDelimiter(
+      "0xb1a8f7c700000000000000000000000000000000000000000000000000000000000000ca00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000022000100000000000000000000000000000000000000000000000000000000000c3500000000000000000000000000000000000000000000000000000000000000",
+    );
+    expect(address).toEqual(undefined);
+  });
 });

src/modules/referral/services/service.ts

@@ -170,19 +170,15 @@ export class ReferralService {
     return { referralRate: 0.4, tier: 1 };
   }
 
+  /**
+   * Returns the calldata string without the arguments of the deposit function
+   * @param data
+   */
   public subtractFunctionArgsFromCallData(data: string) {
-    const coder = new ethers.utils.AbiCoder();
-    // strip hex method identifier
-    const dataNoMethod = ethers.utils.hexDataSlice(data, 4);
-    // keep method hex identifier
-    const methodHex = data.replace(dataNoMethod.replace("0x", ""), "");
-    const decodedData = coder.decode(
-      ["address", "address", "uint256", "uint256", "uint64", "uint32"],
-      ethers.utils.hexDataSlice(data, 4),
-    );
-    const encoded = coder.encode(["address", "address", "uint256", "uint256", "uint64", "uint32"], decodedData);
-    const fullEncoded = methodHex + encoded.replace("0x", "");
-    return data.replace(fullEncoded, "");
+    // the length of the string including the method identifier and
+    // the deposit function args ["address", "address", "uint256", "uint256", "uint64", "uint32"]
+    const methodIdAndArgsLength = 395;
+    return data.slice(methodIdAndArgsLength - 1);
   }
 
   public extractReferralAddressUsingDelimiter(data: string) {