fix: readObject when reading from packed objects with format wrapped (#1935)

* fix: return packed object result early in readObject.js

* chore: simplify conditional logic in readObject.js

* chore: add tests for reading different format objects from packfile

* docs: add @limond as a contributor

Author: limond

js/isomorphic-git/README.md

@@ -374,6 +374,7 @@ Thanks goes to these wonderful people ([emoji key](https://github.com/kentcdodds
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/lsegurado"><img src="https://avatars.githubusercontent.com/u/27731047?v=4?s=60" width="60px;" alt=""/><br /><sub><b>Lucas Martin Segurado</b></sub></a><br /><a href="https://github.com/isomorphic-git/isomorphic-git/commits?author=lsegurado" title="Documentation">📖</a> <a href="https://github.com/isomorphic-git/isomorphic-git/issues?q=author%3Alsegurado" title="Bug reports">🐛</a></td>
+    <td align="center"><a href="https://github.com/limond"><img src="https://avatars.githubusercontent.com/u/1025682?v=4?s=60" width="60px;" alt=""/><br /><sub><b>Leon Kaucher</b></sub></a><br /><a href="https://github.com/isomorphic-git/isomorphic-git/commits?author=limond" title="Code">💻</a> <a href="https://github.com/isomorphic-git/isomorphic-git/commits?author=limond" title="Tests">⚠️</a></td>
   </tr>
 </table>
 

js/isomorphic-git/index.cjs

@@ -3137,43 +3137,46 @@ async function _readObject({
       oid,
       getExternalRefDelta,
     });
-  }
-  // Finally
-  if (!result) {
-    throw new NotFoundError(oid)
+
+    if (!result) {
+      throw new NotFoundError(oid)
+    }
+
+    // Directly return packed result, as specified: packed objects always return the 'content' format.
+    return result
   }
 
+  // Loose objects are always deflated, return early
   if (format === 'deflated') {
     return result
   }
 
+  // All loose objects are deflated but the hard-coded empty tree is `wrapped` so we have to check if we need to inflate the object.
   if (result.format === 'deflated') {
     result.object = Buffer.from(await inflate(result.object));
     result.format = 'wrapped';
   }
 
-  if (result.format === 'wrapped') {
-    if (format === 'wrapped' && result.format === 'wrapped') {
-      return result
-    }
-    const sha = await shasum(result.object);
-    if (sha !== oid) {
-      throw new InternalError(
-        `SHA check failed! Expected ${oid}, computed ${sha}`
-      )
-    }
-    const { object, type } = GitObject.unwrap(result.object);
-    result.type = type;
-    result.object = object;
-    result.format = 'content';
+  if (format === 'wrapped') {
+    return result
   }
 
-  if (result.format === 'content') {
-    if (format === 'content') return result
-    return
+  const sha = await shasum(result.object);
+  if (sha !== oid) {
+    throw new InternalError(
+      `SHA check failed! Expected ${oid}, computed ${sha}`
+    )
+  }
+  const { object, type } = GitObject.unwrap(result.object);
+  result.type = type;
+  result.object = object;
+  result.format = 'content';
+
+  if (format === 'content') {
+    return result
   }
 
-  throw new InternalError(`invalid format "${result.format}"`)
+  throw new InternalError(`invalid requested format "${format}"`)
 }
 
 class AlreadyExistsError extends BaseError {

js/isomorphic-git/index.js

@@ -3131,43 +3131,46 @@ async function _readObject({
       oid,
       getExternalRefDelta,
     });
-  }
-  // Finally
-  if (!result) {
-    throw new NotFoundError(oid)
+
+    if (!result) {
+      throw new NotFoundError(oid)
+    }
+
+    // Directly return packed result, as specified: packed objects always return the 'content' format.
+    return result
   }
 
+  // Loose objects are always deflated, return early
   if (format === 'deflated') {
     return result
   }
 
+  // All loose objects are deflated but the hard-coded empty tree is `wrapped` so we have to check if we need to inflate the object.
   if (result.format === 'deflated') {
     result.object = Buffer.from(await inflate(result.object));
     result.format = 'wrapped';
   }
 
-  if (result.format === 'wrapped') {
-    if (format === 'wrapped' && result.format === 'wrapped') {
-      return result
-    }
-    const sha = await shasum(result.object);
-    if (sha !== oid) {
-      throw new InternalError(
-        `SHA check failed! Expected ${oid}, computed ${sha}`
-      )
-    }
-    const { object, type } = GitObject.unwrap(result.object);
-    result.type = type;
-    result.object = object;
-    result.format = 'content';
+  if (format === 'wrapped') {
+    return result
   }
 
-  if (result.format === 'content') {
-    if (format === 'content') return result
-    return
+  const sha = await shasum(result.object);
+  if (sha !== oid) {
+    throw new InternalError(
+      `SHA check failed! Expected ${oid}, computed ${sha}`
+    )
+  }
+  const { object, type } = GitObject.unwrap(result.object);
+  result.type = type;
+  result.object = object;
+  result.format = 'content';
+
+  if (format === 'content') {
+    return result
   }
 
-  throw new InternalError(`invalid format "${result.format}"`)
+  throw new InternalError(`invalid requested format "${format}"`)
 }
 
 class AlreadyExistsError extends BaseError {