Add explicit type check

bindings/node.js/kzg.ts

@@ -82,10 +82,11 @@ function requireSetupHandle(): SetupHandle {
 }
 
 function checkBlob(blob: Blob) {
+  if (!(blob instanceof Uint8Array)) {
+    throw new Error("Expected blob to be a UInt8Array.");
+  }
   if (blob.length != BYTES_PER_BLOB) {
-    throw new Error(
-      `Expected blob to be UInt8Array of ${BYTES_PER_BLOB} bytes.`,
-    );
+    throw new Error(`Expected blob to be ${BYTES_PER_BLOB} bytes.`);
   }
 }
 
@@ -96,10 +97,11 @@ function checkBlobs(blobs: Blob[]) {
 }
 
 function checkCommitment(commitment: KZGCommitment) {
+  if (!(commitment instanceof Uint8Array)) {
+    throw new Error("Expected commitment to be a UInt8Array.");
+  }
   if (commitment.length != BYTES_PER_COMMITMENT) {
-    throw new Error(
-      `Expected commitment to be UInt8Array of ${BYTES_PER_COMMITMENT} bytes.`,
-    );
+    throw new Error(`Expected commitment to be ${BYTES_PER_COMMITMENT} bytes.`);
   }
 }
 
@@ -110,10 +112,11 @@ function checkCommitments(commitments: KZGCommitment[]) {
 }
 
 function checkProof(proof: KZGProof) {
+  if (!(proof instanceof Uint8Array)) {
+    throw new Error("Expected proof to be a UInt8Array.");
+  }
   if (proof.length != BYTES_PER_PROOF) {
-    throw new Error(
-      `Expected proof to be UInt8Array of ${BYTES_PER_PROOF} bytes.`,
-    );
+    throw new Error(`Expected proof to be ${BYTES_PER_PROOF} bytes.`);
   }
 }
 
@@ -124,9 +127,12 @@ function checkProofs(proofs: KZGProof[]) {
 }
 
 function checkFieldElement(field: Bytes32) {
+  if (!(field instanceof Uint8Array)) {
+    throw new Error("Expected field element to be a UInt8Array.");
+  }
   if (field.length != BYTES_PER_FIELD_ELEMENT) {
     throw new Error(
-      `Expected field element to be UInt8Array of ${BYTES_PER_FIELD_ELEMENT} bytes.`,
+      `Expected field element to be ${BYTES_PER_FIELD_ELEMENT} bytes.`,
     );
   }
 }

bindings/node.js/test.ts

@@ -205,14 +205,14 @@ describe("C-KZG", () => {
     it("throws as expected when given an argument of invalid type", () => {
       // @ts-expect-error
       expect(() => blobToKzgCommitment("wrong type")).toThrowError(
-        "Expected blob to be UInt8Array of 131072 bytes",
+        "Expected blob to be a UInt8Array",
       );
     });
 
     it("throws as expected when given an argument of invalid length", () => {
       expect(() =>
         blobToKzgCommitment(randomBytes(BYTES_PER_BLOB - 1)),
-      ).toThrowError("Expected blob to be UInt8Array of 131072 bytes");
+      ).toThrowError("Expected blob to be 131072 bytes");
     });
   });
 
@@ -281,6 +281,13 @@ describe("C-KZG", () => {
   });
 
   describe("edge cases for verifyBlobKzgProofBatch", () => {
+    it("should reject non-bytearray blob", () => {
+      expect(() =>
+        // @ts-expect-error
+        verifyBlobKzgProofBatch(["foo", "bar"], [], []),
+      ).toThrowError("Expected blob to be a UInt8Array");
+    });
+
     it("zero blobs/commitments/proofs should verify as true", () => {
       expect(verifyBlobKzgProofBatch([], [], [])).toBe(true);
     });