From 388ac02b0ed79e79d227c12e6ffb1195155561ef Mon Sep 17 00:00:00 2001
From: Offroaders123 <65947371+Offroaders123@users.noreply.github.com>
Date: Fri, 2 Feb 2024 17:54:47 -0800
Subject: [PATCH] NBT Error Parse Info

Working on figuring out the concepts behind making your own error handlers, in that I can provide the missing metadata I need to be able to get without needing to parse the error message itself.

This is a big of a weird setup at the moment, since I don't quite know the correct way to structure these kinds of extensions.

https://developer.mozilla.org/en-US/docs/Web/API/DOMException
https://stackoverflow.com/questions/5136727/manually-artificially-throwing-a-domexception-with-javascript
https://javascript.info/custom-errors
https://stackoverflow.com/questions/67558074/how-to-throw-custom-errors
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause

#31
---
 src/error.ts | 20 ++++++++++++++++++++
 src/index.ts |  1 +
 src/read.ts  |  3 ++-
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 src/error.ts

diff --git a/src/error.ts b/src/error.ts
new file mode 100644
index 0000000..9e3e449
--- /dev/null
+++ b/src/error.ts
@@ -0,0 +1,20 @@
+import type { NBTData } from "./format.js";
+
+export interface NBTErrorOptions extends ErrorOptions {
+  byteOffset: number;
+  cause: NBTData;
+  remaining: number;
+}
+
+export class NBTError extends Error {
+  byteOffset: number;
+  override cause: NBTData;
+  remaining: number;
+
+  constructor(message: string, options: NBTErrorOptions) {
+    super(message,options);
+    this.byteOffset = options.byteOffset;
+    this.cause = options.cause;
+    this.remaining = options.remaining;
+  }
+}
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index 1481f7e..8411ade 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -5,4 +5,5 @@ export * from "./stringify.js";
 export * from "./format.js";
 export * from "./tag.js";
 export * from "./primitive.js";
+export * from "./error.js";
 export * from "./compression.js";
\ No newline at end of file
diff --git a/src/read.ts b/src/read.ts
index 69fe1cc..89c0d18 100644
--- a/src/read.ts
+++ b/src/read.ts
@@ -2,6 +2,7 @@ import { NBTData } from "./format.js";
 import { Int8, Int16, Int32, Float32 } from "./primitive.js";
 import { TAG, TAG_TYPE } from "./tag.js";
 import { decompress } from "./compression.js";
+import { NBTError } from "./error.js";
 
 import type { RootName, Endian, Compression, BedrockLevel } from "./format.js";
 import type { Tag, RootTag, RootTagLike, ByteTag, ShortTag, IntTag, LongTag, FloatTag, DoubleTag, StringTag, ByteArrayTag, ListTag, CompoundTag, IntArrayTag, LongArrayTag } from "./tag.js";
@@ -199,7 +200,7 @@ export class NBTReader {
 
     if (strict && data.byteLength > this.#byteOffset){
       const remaining = data.byteLength - this.#byteOffset;
-      throw new Error(`Encountered unexpected End tag at byte offset ${this.#byteOffset}, ${remaining} unread bytes remaining`);
+      throw new NBTError(`Encountered unexpected End tag at byte offset ${this.#byteOffset}, ${remaining} unread bytes remaining`,{ byteOffset: this.#byteOffset, cause: new NBTData<RootTag>(value as RootTag,{ rootName, endian }), remaining });
     }
 
     return new NBTData<T>(value,{ rootName, endian });