From b95a6e2b0d8559d63e3c63c11694e67636c65e5d Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Fri, 18 Jun 2021 16:06:06 +1000
Subject: [PATCH] chore: allow access to full header in CarReader

---
 examples/car-to-fixture.js |  5 +----
 lib/reader-browser.js      | 20 ++++++++++----------
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/examples/car-to-fixture.js b/examples/car-to-fixture.js
index 740b859..0556679 100755
--- a/examples/car-to-fixture.js
+++ b/examples/car-to-fixture.js
@@ -42,10 +42,7 @@ async function run () {
   const indexer = await CarIndexer.fromBytes(bytes)
   const reader = await CarReader.fromBytes(bytes)
   const fixture = {
-    header: {
-      roots: await reader.getRoots(),
-      version: reader.version
-    },
+    header: reader._header, // a little naughty but we need gory details
     blocks: []
   }
   let i = 0
diff --git a/lib/reader-browser.js b/lib/reader-browser.js
index d520922..471f551 100644
--- a/lib/reader-browser.js
+++ b/lib/reader-browser.js
@@ -5,6 +5,8 @@ import { asyncIterableReader, bytesReader, createDecoder } from './decoder.js'
  * @typedef {import('../api').Block} Block
  * @typedef {import('../api').CarReader} CarReaderIface
  * @typedef {import('./coding').BytesReader} BytesReader
+ * @typedef {import('./coding').CarHeader} CarHeader
+ * @typedef {import('./coding').CarV2Header} CarV2Header
  */
 
 /**
@@ -26,18 +28,16 @@ import { asyncIterableReader, bytesReader, createDecoder } from './decoder.js'
  * @class
  * @implements {CarReaderIface}
  * @property {number} version The version number of the CAR referenced by this
- * reader (should be `1`).
+ * reader (should be `1` or `2`).
  */
 export class CarReader {
   /**
    * @constructs CarReader
-   * @param {number} version
-   * @param {CID[]} roots
+   * @param {CarHeader|CarV2Header} header
    * @param {Block[]} blocks
    */
-  constructor (version, roots, blocks) {
-    this._version = version
-    this._roots = roots
+  constructor (header, blocks) {
+    this._header = header
     this._blocks = blocks
     this._keys = blocks.map((b) => b.cid.toString())
   }
@@ -48,7 +48,7 @@ export class CarReader {
    * @instance
    */
   get version () {
-    return this._version
+    return this._header.version
   }
 
   /**
@@ -62,7 +62,7 @@ export class CarReader {
    * @returns {Promise<CID[]>}
    */
   async getRoots () {
-    return this._roots
+    return this._header.roots
     /* c8 ignore next 2 */
     // Node.js 12 c8 bug
   }
@@ -192,13 +192,13 @@ export class CarReader {
  */
 export async function decodeReaderComplete (reader) {
   const decoder = createDecoder(reader)
-  const { version, roots } = await decoder.header()
+  const header = await decoder.header()
   const blocks = []
   for await (const block of decoder.blocks()) {
     blocks.push(block)
   }
 
-  return new CarReader(version, roots, blocks)
+  return new CarReader(header, blocks)
   /* c8 ignore next 2 */
   // Node.js 12 c8 bug
 }