From 60b56c9f66efa24e8fe943a13e4f2d76e0b80964 Mon Sep 17 00:00:00 2001
From: Russell Dempsey <1173416+SgtPooki@users.noreply.github.com>
Date: Mon, 4 Mar 2024 17:35:45 -0800
Subject: [PATCH] chore: some cleanup and code coverage

---
 .../src/utils/request-headers.ts              | 12 ++---
 packages/verified-fetch/src/verified-fetch.ts | 50 +++++++++++--------
 .../test/utils/request-headers.spec.ts        |  6 ++-
 3 files changed, 37 insertions(+), 31 deletions(-)

diff --git a/packages/verified-fetch/src/utils/request-headers.ts b/packages/verified-fetch/src/utils/request-headers.ts
index 124f4209..109bae8f 100644
--- a/packages/verified-fetch/src/utils/request-headers.ts
+++ b/packages/verified-fetch/src/utils/request-headers.ts
@@ -13,14 +13,12 @@ export function getHeader (headers: HeadersInit | undefined, header: string): st
     const entry = headers.find(([key]) => key.toLowerCase() === header.toLowerCase())
     return entry?.[1]
   }
-  if (typeof headers === 'object') {
-    const key = Object.keys(headers).find(k => k.toLowerCase() === header.toLowerCase())
-    if (key == null) {
-      return undefined
-    }
-    return headers[key]
+  const key = Object.keys(headers).find(k => k.toLowerCase() === header.toLowerCase())
+  if (key == null) {
+    return undefined
   }
-  return headers[header]
+
+  return headers[key]
 }
 
 /**
diff --git a/packages/verified-fetch/src/verified-fetch.ts b/packages/verified-fetch/src/verified-fetch.ts
index 3da6f074..60cde747 100644
--- a/packages/verified-fetch/src/verified-fetch.ts
+++ b/packages/verified-fetch/src/verified-fetch.ts
@@ -378,28 +378,9 @@ export class VerifiedFetch {
           length = rangeWithSize.length
         }
       }
-
-      if (offset != null) {
-        if (offset < 0) {
-          // the requested range start is negative
-          this.log.error('range start %d is negative', offset)
-          return badRangeResponse(resource)
-        } else if (stat.fileSize < offset) {
-          // the requested range start is larger than the requested content size
-          this.log.error('range start %d is larger than the requested content size %d', offset, stat.fileSize)
-          return badRangeResponse(resource)
-        } else if (length != null && Number(stat.fileSize) < (offset + length)) {
-          // the requested range is larger than the requested content size
-          this.log.error('range end %d is larger than the requested content size %d', offset + length, stat.fileSize)
-          return badRangeResponse(resource)
-        }
-      }
-      if (length != null) {
-        if (Number(stat.fileSize) < length) {
-          // the requested range is larger than the requested content size
-          this.log.error('range end %d is larger than the requested content size %d', length, stat.fileSize)
-          return badRangeResponse(resource)
-        }
+      const resp = this.checkForInvalidRangeRequest({ stat, offset, length, resource })
+      if (resp != null) {
+        return resp
       }
     }
 
@@ -487,6 +468,31 @@ export class VerifiedFetch {
     response.headers.set('content-type', contentType)
   }
 
+  private checkForInvalidRangeRequest ({ offset, length, resource, stat }: { offset?: number, length?: number, resource: string, stat: UnixFSStats }): Response | undefined {
+    if (offset != null) {
+      if (offset < 0) {
+        // the requested range start is negative
+        this.log.error('range start %d is negative', offset)
+        return badRangeResponse(resource)
+      } else if (stat.fileSize < offset) {
+        // the requested range start is larger than the requested content size
+        this.log.error('range start %d is larger than the requested content size %d', offset, stat.fileSize)
+        return badRangeResponse(resource)
+      } else if (length != null && Number(stat.fileSize) < (offset + length)) {
+        // the requested range is larger than the requested content size
+        this.log.error('range end %d is larger than the requested content size %d', offset + length, stat.fileSize)
+        return badRangeResponse(resource)
+      }
+    }
+    if (length != null) {
+      if (Number(stat.fileSize) < length) {
+        // the requested range is larger than the requested content size
+        this.log.error('range end %d is larger than the requested content size %d', length, stat.fileSize)
+        return badRangeResponse(resource)
+      }
+    }
+  }
+
   /**
    * If the user has not specified an Accept header or format query string arg,
    * use the CID codec to choose an appropriate handler for the block data.
diff --git a/packages/verified-fetch/test/utils/request-headers.spec.ts b/packages/verified-fetch/test/utils/request-headers.spec.ts
index 12d7b730..9bfbbae3 100644
--- a/packages/verified-fetch/test/utils/request-headers.spec.ts
+++ b/packages/verified-fetch/test/utils/request-headers.spec.ts
@@ -4,8 +4,10 @@ import { getHeader, getRequestRange } from '../../src/utils/request-headers.js'
 describe('request-headers', () => {
   describe('getHeader', () => {
     it('should return undefined when headers are undefined', () => {
-      const result = getHeader(undefined, 'dummy')
-      expect(result).to.be.undefined()
+      expect(getHeader(undefined, 'dummy')).to.be.undefined()
+      expect(getHeader(new Headers(), 'dummy')).to.be.undefined()
+      expect(getHeader({}, 'dummy')).to.be.undefined()
+      expect(getHeader([], 'dummy')).to.be.undefined()
     })
 
     it('should return correct header value for Headers instance', () => {