make sure Decoder raises DecodeError or DataViewIndexOutOfBoundsError

src/DecodeError.ts

@@ -0,0 +1,16 @@
+
+export class DecodeError extends Error {
+  constructor(message: string) {
+    super(message);
+
+    // fix the prototype chain in a cross-platform way
+    const proto: typeof DecodeError.prototype = Object.create(DecodeError.prototype);
+    Object.setPrototypeOf(this, proto);
+
+    Object.defineProperty(this, "name", {
+      configurable: true,
+      enumerable: false,
+      value: DecodeError.name,
+    });
+  }
+}

src/Decoder.ts

@@ -4,6 +4,7 @@ import { getInt64, getUint64 } from "./utils/int";
 import { utf8DecodeJs, TEXT_DECODER_THRESHOLD, utf8DecodeTD } from "./utils/utf8";
 import { createDataView, ensureUint8Array } from "./utils/typedArrays";
 import { CachedKeyDecoder, KeyDecoder } from "./CachedKeyDecoder";
+import { DecodeError } from "./DecodeError";
 
 const enum State {
   ARRAY,
@@ -60,22 +61,6 @@ const DEFAULT_MAX_LENGTH = 0xffff_ffff; // uint32_max
 
 const sharedCachedKeyDecoder = new CachedKeyDecoder();
 
-export class DecodeError extends Error {
-  constructor(message: string) {
-    super(message);
-
-    // fix the prototype chain in a cross-platform way
-    const proto: typeof DecodeError.prototype = Object.create(DecodeError.prototype);
-    Object.setPrototypeOf(this, proto);
-
-    Object.defineProperty(this, "name", {
-      configurable: true,
-      enumerable: false,
-      value: DecodeError.name,
-    });
-  }
-}
-
 export class Decoder<ContextType = undefined> {
   private totalPos = 0;
   private pos = 0;
@@ -133,6 +118,10 @@ export class Decoder<ContextType = undefined> {
     return new RangeError(`Extra ${view.byteLength - pos} of ${view.byteLength} byte(s) found at buffer[${posToShow}]`);
   }
 
+  /**
+   * @throws {DecodeError}
+   * @throws {RangeError}
+   */
   public decode(buffer: ArrayLike<number> | BufferSource): unknown {
     this.reinitializeState();
     this.setBuffer(buffer);

src/index.ts

@@ -13,8 +13,9 @@ export { DecodeOptions };
 import { decodeAsync, decodeArrayStream, decodeMultiStream, decodeStream } from "./decodeAsync";
 export { decodeAsync, decodeArrayStream, decodeMultiStream, decodeStream };
 
-import { Decoder, DecodeError } from "./Decoder";
-export { Decoder, DecodeError };
+import { Decoder, DataViewIndexOutOfBoundsError } from "./Decoder";
+import { DecodeError } from "./DecodeError";
+export { Decoder, DecodeError, DataViewIndexOutOfBoundsError };
 
 import { Encoder } from "./Encoder";
 export { Encoder };

src/timestamp.ts

@@ -1,4 +1,5 @@
 // https://github.com/msgpack/msgpack/blob/master/spec.md#timestamp-extension-type
+import { DecodeError } from "./DecodeError";
 import { getInt64, setInt64 } from "./utils/int";
 
 export const EXT_TIMESTAMP = -1;
@@ -91,7 +92,7 @@ export function decodeTimestampToTimeSpec(data: Uint8Array): TimeSpec {
       return { sec, nsec };
     }
     default:
-      throw new Error(`Unrecognized data size for timestamp: ${data.length}`);
+      throw new DecodeError(`Unrecognized data size for timestamp (expected 4, 8, or 12): ${data.length}`);
   }
 }