From edf96f2c9ab872e2d4aa84c06564f136b0086018 Mon Sep 17 00:00:00 2001
From: EnixCoda <enixcoda@gmail.com>
Date: Sat, 27 Jun 2020 16:58:07 +0800
Subject: [PATCH] fix: fetch complete diff data

---
 src/platforms/GitHub/API.ts       |  9 ++++++---
 src/platforms/GitHub/DOMHelper.ts | 23 +++++++++++++++++++++++
 src/platforms/GitHub/index.ts     | 18 ++++++++++++++----
 3 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/src/platforms/GitHub/API.ts b/src/platforms/GitHub/API.ts
index 6b7cbf7..518a568 100644
--- a/src/platforms/GitHub/API.ts
+++ b/src/platforms/GitHub/API.ts
@@ -93,11 +93,14 @@ export async function getPullTreeData(
 export async function getPullPageDocument(
   userName: string,
   repoName: string,
-  pullId: string,
+  pullId: string, // not used
+  baseSHA: string,
+  headSHA: string,
 ): Promise<Document> {
   const search = new URLSearchParams(window.location.search)
-  search.set('_pjax', '#js-repo-pjax-container')
-  const url = `https://${window.location.host}/${userName}/${repoName}/pull/${pullId}/files?${search}`
+  search.set('sha1', baseSHA)
+  search.set('sha2', headSHA)
+  const url = `https://${window.location.host}/${userName}/${repoName}/diffs?${search}`
   return new DOMParser().parseFromString(await (await fetch(url)).text(), 'text/html')
 }
 
diff --git a/src/platforms/GitHub/DOMHelper.ts b/src/platforms/GitHub/DOMHelper.ts
index 0d141f6..6919671 100644
--- a/src/platforms/GitHub/DOMHelper.ts
+++ b/src/platforms/GitHub/DOMHelper.ts
@@ -16,6 +16,29 @@ export function getIssueTitle() {
   if (title && id) return `${id} ${title}`
 }
 
+export function getPullSHA() {
+  return $('#js-repo-pjax-container', e => {
+    const commentNodes: ChildNode[] = []
+    e.childNodes.forEach(node => {
+      if (node.nodeType === document.COMMENT_NODE) {
+        commentNodes.push(node)
+      }
+    })
+    let baseSHA, headSHA
+    for (const node of commentNodes) {
+      const matchBase = node.textContent?.match(/base sha1:.*?(\w{40})/)
+      if (matchBase) baseSHA = matchBase[1]
+      const matchHead = node.textContent?.match(/head sha1:.*?(\w{40})/)
+      if (matchHead) headSHA = matchHead[1]
+    }
+    if (baseSHA && headSHA)
+      return {
+        baseSHA,
+        headSHA,
+      }
+  })
+}
+
 export function getCurrentBranch() {
   const selectedBranchButtonSelector = [
     '.repository-content #branch-select-menu summary',
diff --git a/src/platforms/GitHub/index.ts b/src/platforms/GitHub/index.ts
index c0b33e4..9a6ce27 100644
--- a/src/platforms/GitHub/index.ts
+++ b/src/platforms/GitHub/index.ts
@@ -1,3 +1,4 @@
+import { raiseError } from 'analytics'
 import { GITHUB_OAUTH } from 'env'
 import { Base64 } from 'js-base64'
 import { platform } from 'platforms'
@@ -194,10 +195,19 @@ export const GitHub: Platform = {
 }
 
 async function createPullFileResolver(userName: string, repoName: string, pullId: string) {
-  const doc =
-    URLHelper.parse().path[1] === 'files'
-      ? document
-      : await API.getPullPageDocument(userName, repoName, pullId)
+  let doc: Document
+  if (URLHelper.parse().path[1] === 'files') {
+    doc = document
+  } else {
+    const shas = DOMHelper.getPullSHA()
+    if (!shas) {
+      raiseError(new Error(`Cannot resolve sha from DOM`))
+      doc = document
+      // fallback, at least not throw error
+    } else {
+      doc = await API.getPullPageDocument(userName, repoName, pullId, shas.baseSHA, shas.headSHA)
+    }
+  }
 
   return (path: string) => {
     const id = doc.querySelector(`*[data-path^="${path}"]`)?.parentElement?.id