Merge pull request #37 from ChainSafe/expected-errors

Prevent "BLS not initialized" error from causing a false negative

src/errors.ts

@@ -0,0 +1,5 @@
+/**
+ * Indicate that this error is expected and should not be ignored
+ * by the functional interface try / catch blocks
+ */
+export class ExpectedError extends Error {}

src/functional.ts

@@ -1,5 +1,6 @@
-import {validateBytes} from "./helpers";
 import {IBls} from "./interface";
+import {validateBytes} from "./helpers";
+import {ExpectedError} from "./errors";
 
 // Returned type is enforced at each implementation's index
 // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
@@ -53,6 +54,7 @@ export function functionalInterfaceFactory({
     try {
       return Signature.fromBytes(signature).verify(PublicKey.fromBytes(publicKey), message);
     } catch (e) {
+      if (e instanceof ExpectedError) throw e;
       return false;
     }
   }
@@ -74,6 +76,7 @@ export function functionalInterfaceFactory({
         message
       );
     } catch (e) {
+      if (e instanceof ExpectedError) throw e;
       return false;
     }
   }
@@ -99,6 +102,7 @@ export function functionalInterfaceFactory({
         messages.map((msg) => msg)
       );
     } catch (e) {
+      if (e instanceof ExpectedError) throw e;
       return false;
     }
   }

src/herumi/context.ts

@@ -1,5 +1,6 @@
 /* eslint-disable require-atomic-updates */
 import bls from "bls-eth-wasm";
+import {ExpectedError} from "../errors";
 
 type Bls = typeof bls;
 let blsGlobal: Bls | null = null;
@@ -27,7 +28,7 @@ export function destroy(): void {
 
 export function getContext(): Bls {
   if (!blsGlobal) {
-    throw new Error("BLS not initialized");
+    throw new ExpectedError("BLS not initialized");
   }
   return blsGlobal;
 }