Add commits dropdown in PR files view and allow commit by commit review (#25528)

This PR adds a new dropdown to select a commit or a commit range
(shift-click like github) of a Pull Request.
After selection of a commit only the changes of this commit will be shown.
When selecting a range of commits the diff of this range is shown.

This allows to review a PR commit by commit or by viewing only commit ranges.
The "Show changes since your last review" mechanism github uses is implemented, too.
When reviewing a single commit or a commit range the "Viewed" functionality is disabled.

## Screenshots

### The commit dropdown

![image](0db3ae62-1272-436c-be64-4730c5d611e3)

### Selecting a commit range

![image](ad81eedb-8437-42b0-8073-2d940c25fe8f)

### Show changes of a single commit only

![image](6b1a113b-73ef-4ecc-adf6-bc2340bb8f97)

### Show changes of a commit range

![image](6401b358-cd66-4c09-8baa-6cf6177f23a7)


Fixes https://github.com/go-gitea/gitea/issues/20989
Fixes https://github.com/go-gitea/gitea/issues/19263

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>

tests/gitea-repositories-meta/user2/commitsonpr.git/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

tests/gitea-repositories-meta/user2/commitsonpr.git/config

@@ -0,0 +1,4 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = true

tests/gitea-repositories-meta/user2/commitsonpr.git/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

tests/gitea-repositories-meta/user2/commitsonpr.git/info/exclude

@@ -0,0 +1,6 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~

tests/gitea-repositories-meta/user2/commitsonpr.git/info/refs

@@ -0,0 +1,3 @@
+1978192d98bb1b65e11c2cf37da854fbf94bffd6	refs/heads/branch1
+cbff181af4c9c7fee3cf6c106699e07d9a3f54e6	refs/heads/main
+1978192d98bb1b65e11c2cf37da854fbf94bffd6	refs/pull/1/head

tests/gitea-repositories-meta/user2/commitsonpr.git/logs/HEAD

@@ -0,0 +1 @@
+0000000000000000000000000000000000000000 cbff181af4c9c7fee3cf6c106699e07d9a3f54e6 Gitea <gitea@fake.local> 1688672318 +0200

tests/gitea-repositories-meta/user2/commitsonpr.git/logs/refs/heads/branch1

@@ -0,0 +1 @@
+0000000000000000000000000000000000000000 1978192d98bb1b65e11c2cf37da854fbf94bffd6 Gitea <gitea@fake.local> 1688672383 +0200	push

tests/gitea-repositories-meta/user2/commitsonpr.git/logs/refs/heads/main

@@ -0,0 +1 @@
+0000000000000000000000000000000000000000 cbff181af4c9c7fee3cf6c106699e07d9a3f54e6 root <sauer.sebastian@gmail.com> 1688672317 +0200	push

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/23/576dd018294e476c06e569b6b0f170d0558705

@@ -0,0 +1,2 @@
+x
¥ŽA
+Â0E]ç³$™´™D¼ƒ'˜If´`­´éý­OàêÁƒ÷ùež¦±
váÐUˆC©\Q;_ò<5F>™…%VÏHÆæ<C386>DS Ú»7/újPú„ÉJV³žT‚	å$>Ô®zC‹Foí1/pSáµ<C3A1>ü‚oºÀyýâ´þôõ>ñø<•yº@HÃ<48>#E8zôÞív?Ûöì¯×tmйJÝNê

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/81/1d46c7e518f4f180afb862c0db5cb8c80529ce

@@ -0,0 +1,2 @@
+x
¥<>M
+ֲ0F]ח³ֺה§<D794>	ˆx‡<78>`ׂL´`­´י‎<D799>Oאךƒ<07>דMכ²ּ\°§÷©‚c;₪R²`<60>°8Oװ«„₪<E2809E>bVִ<56>‹gפז-›¾*LװXך)<06>‚q9זּ>ה>‘÷ֲ<05>"9ךc<D79A>`װ${<7B>ו£÷ֱe<D6B1>N·<4E>נם¾ָ<C2BE>ל¦u¹‚˜j
־טM£-¶¶<C2B6>_Su¯@ז¼DLג

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/83/7d5c8125633d7d258f93b998e867eab0145520

@@ -0,0 +1,3 @@
+x
¥ŽA
+Â0E]ç³ÊL'MRñ=Á$™hÁZiÓûžÀՇǟŸÖe™+ô–NuS…àSNÄÌe(D^ƾpÒâƒFEF"²‘¡y˦¯
+Þúœ#èÄA+¾‘€­>8QreÔ‘9'#G}¬Le¯³¼`’C7¸ìßèö¾Ý™Ÿ]Z—+<2B>Áùž=Ã{DÓh;[›ö׌©ºWÍȵM

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/87/cdc1333f5f117a92f3cef78ebe0301114b3610

@@ -0,0 +1,2 @@
+x
+)JMU067`040031QrutńuŐËMa¸–ďšĎ!Ľ´E~óÓŹGŠYM…**I-.1Ô+©(axsóď­<C48F>F‡Đw‰S…îŘ%˝gS’"#°"ˬ€Ů)ýôBSć
+p·˝Ř™sŕ)’"c°˘KáS÷ď‘ö°Ě¬köžZ›xÂv¦?’"°˘é<±ŻKŐf؇ú­Z¸u"ÓĺÇľ#)2+2ý`'ž÷ě’OŰÖ3ËfEs/Z †¤Č¬¨Y×ř‰ĹĄ-+ňw5žN߬+›¸Bă4’"s°˘ŕY*Ťę¬ßKZÂú˛®ßn)ó‘d><3E>¤Č¬<>+÷–łLѲ%«DĎx,9]K*ô<>’"K°"<22>Yěđăč­»óAÂ|ŞÄ–ɉźZ
vۓG

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/c5/626fc9eff57eb1bb7b796b01d4d0f2f3f792a2

@@ -0,0 +1,2 @@
+x
ĄŽA
+Â0E]çłĘ4I3ń=Á$L´`¬4éý­OŕęÁ<C499>÷ůy­ué`ýxę›*°%L=Ó<>AEÂT˛F‹Łě)bˇŔČć-›ľ:pČZĽP"›\¶ťGŃP0—ivĘH”ŮŮűcÝ`Ö$­/ň‚YvÝŕŇľÚOßîU–ç<E28093>×z…1ÄČ:rpF‹h{śíGö׌éÚ:8ó
•ELÇ

tests/gitea-repositories-meta/user2/commitsonpr.git/objects/info/packs

@@ -0,0 +1 @@
+

tests/gitea-repositories-meta/user2/commitsonpr.git/refs/heads/branch1

@@ -0,0 +1 @@
+1978192d98bb1b65e11c2cf37da854fbf94bffd6

tests/gitea-repositories-meta/user2/commitsonpr.git/refs/heads/main

@@ -0,0 +1 @@
+cbff181af4c9c7fee3cf6c106699e07d9a3f54e6

tests/gitea-repositories-meta/user2/commitsonpr.git/refs/heads/master

@@ -0,0 +1 @@
+cbff181af4c9c7fee3cf6c106699e07d9a3f54e6

tests/gitea-repositories-meta/user2/commitsonpr.git/refs/pull/1/head

@@ -0,0 +1 @@
+1978192d98bb1b65e11c2cf37da854fbf94bffd6

tests/integration/api_issue_test.go

@@ -219,7 +219,7 @@ func TestAPISearchIssues(t *testing.T) {
 	token := getUserToken(t, "user2", auth_model.AccessTokenScopeReadIssue)
 
 	// as this API was used in the frontend, it uses UI page size
-	expectedIssueCount := 16 // from the fixtures
+	expectedIssueCount := 17 // from the fixtures
 	if expectedIssueCount > setting.UI.IssuePagingNum {
 		expectedIssueCount = setting.UI.IssuePagingNum
 	}
@@ -243,7 +243,7 @@ func TestAPISearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.Len(t, apiIssues, 9)
+	assert.Len(t, apiIssues, 10)
 	query.Del("since")
 	query.Del("before")
 
@@ -259,15 +259,15 @@ func TestAPISearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.EqualValues(t, "18", resp.Header().Get("X-Total-Count"))
-	assert.Len(t, apiIssues, 18)
+	assert.EqualValues(t, "19", resp.Header().Get("X-Total-Count"))
+	assert.Len(t, apiIssues, 19)
 
 	query.Add("limit", "10")
 	link.RawQuery = query.Encode()
 	req = NewRequest(t, "GET", link.String())
 	resp = MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.EqualValues(t, "18", resp.Header().Get("X-Total-Count"))
+	assert.EqualValues(t, "19", resp.Header().Get("X-Total-Count"))
 	assert.Len(t, apiIssues, 10)
 
 	query = url.Values{"assigned": {"true"}, "state": {"all"}, "token": {token}}
@@ -296,7 +296,7 @@ func TestAPISearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.Len(t, apiIssues, 7)
+	assert.Len(t, apiIssues, 8)
 
 	query = url.Values{"owner": {"user3"}, "token": {token}} // organization
 	link.RawQuery = query.Encode()
@@ -317,7 +317,7 @@ func TestAPISearchIssuesWithLabels(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
 	// as this API was used in the frontend, it uses UI page size
-	expectedIssueCount := 16 // from the fixtures
+	expectedIssueCount := 17 // from the fixtures
 	if expectedIssueCount > setting.UI.IssuePagingNum {
 		expectedIssueCount = setting.UI.IssuePagingNum
 	}

tests/integration/api_nodeinfo_test.go

@@ -33,7 +33,7 @@ func TestNodeinfo(t *testing.T) {
 		assert.True(t, nodeinfo.OpenRegistrations)
 		assert.Equal(t, "gitea", nodeinfo.Software.Name)
 		assert.Equal(t, 25, nodeinfo.Usage.Users.Total)
-		assert.Equal(t, 18, nodeinfo.Usage.LocalPosts)
+		assert.Equal(t, 19, nodeinfo.Usage.LocalPosts)
 		assert.Equal(t, 2, nodeinfo.Usage.LocalComments)
 	})
 }

tests/integration/api_repo_test.go

@@ -93,9 +93,9 @@ func TestAPISearchRepo(t *testing.T) {
 	}{
 		{
 			name: "RepositoriesMax50", requestURL: "/api/v1/repos/search?limit=50&private=false", expectedResults: expectedResults{
-				nil:   {count: 32},
-				user:  {count: 32},
-				user2: {count: 32},
+				nil:   {count: 33},
+				user:  {count: 33},
+				user2: {count: 33},
 			},
 		},
 		{

tests/integration/issue_test.go

@@ -356,7 +356,7 @@ func TestSearchIssues(t *testing.T) {
 
 	session := loginUser(t, "user2")
 
-	expectedIssueCount := 16 // from the fixtures
+	expectedIssueCount := 17 // from the fixtures
 	if expectedIssueCount > setting.UI.IssuePagingNum {
 		expectedIssueCount = setting.UI.IssuePagingNum
 	}
@@ -377,7 +377,7 @@ func TestSearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.Len(t, apiIssues, 9)
+	assert.Len(t, apiIssues, 10)
 	query.Del("since")
 	query.Del("before")
 
@@ -393,15 +393,15 @@ func TestSearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.EqualValues(t, "18", resp.Header().Get("X-Total-Count"))
-	assert.Len(t, apiIssues, 18)
+	assert.EqualValues(t, "19", resp.Header().Get("X-Total-Count"))
+	assert.Len(t, apiIssues, 19)
 
 	query.Add("limit", "5")
 	link.RawQuery = query.Encode()
 	req = NewRequest(t, "GET", link.String())
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.EqualValues(t, "18", resp.Header().Get("X-Total-Count"))
+	assert.EqualValues(t, "19", resp.Header().Get("X-Total-Count"))
 	assert.Len(t, apiIssues, 5)
 
 	query = url.Values{"assigned": {"true"}, "state": {"all"}}
@@ -430,7 +430,7 @@ func TestSearchIssues(t *testing.T) {
 	req = NewRequest(t, "GET", link.String())
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiIssues)
-	assert.Len(t, apiIssues, 7)
+	assert.Len(t, apiIssues, 8)
 
 	query = url.Values{"owner": {"user3"}} // organization
 	link.RawQuery = query.Encode()
@@ -450,7 +450,7 @@ func TestSearchIssues(t *testing.T) {
 func TestSearchIssuesWithLabels(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
-	expectedIssueCount := 16 // from the fixtures
+	expectedIssueCount := 17 // from the fixtures
 	if expectedIssueCount > setting.UI.IssuePagingNum {
 		expectedIssueCount = setting.UI.IssuePagingNum
 	}

tests/integration/pull_diff_test.go

@@ -0,0 +1,58 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/http"
+	"testing"
+
+	"code.gitea.io/gitea/tests"
+
+	"github.com/PuerkitoBio/goquery"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPullDiff_CompletePRDiff(t *testing.T) {
+	doTestPRDiff(t, "/user2/commitsonpr/pulls/1/files", false, []string{"test1.txt", "test10.txt", "test2.txt", "test3.txt", "test4.txt", "test5.txt", "test6.txt", "test7.txt", "test8.txt", "test9.txt"})
+}
+
+func TestPullDiff_SingleCommitPRDiff(t *testing.T) {
+	doTestPRDiff(t, "/user2/commitsonpr/pulls/1/commits/c5626fc9eff57eb1bb7b796b01d4d0f2f3f792a2", true, []string{"test3.txt"})
+}
+
+func TestPullDiff_CommitRangePRDiff(t *testing.T) {
+	doTestPRDiff(t, "/user2/commitsonpr/pulls/1/files/4ca8bcaf27e28504df7bf996819665986b01c847..23576dd018294e476c06e569b6b0f170d0558705", true, []string{"test2.txt", "test3.txt", "test4.txt"})
+}
+
+func TestPullDiff_StartingFromBaseToCommitPRDiff(t *testing.T) {
+	doTestPRDiff(t, "/user2/commitsonpr/pulls/1/files/c5626fc9eff57eb1bb7b796b01d4d0f2f3f792a2", true, []string{"test1.txt", "test2.txt", "test3.txt"})
+}
+
+func doTestPRDiff(t *testing.T, prDiffURL string, reviewBtnDisabled bool, expectedFilenames []string) {
+	defer tests.PrepareTestEnv(t)()
+
+	session := loginUser(t, "user2")
+
+	req := NewRequest(t, "GET", "/user2/commitsonpr/pulls")
+	session.MakeRequest(t, req, http.StatusOK)
+
+	// Get the given PR diff url
+	req = NewRequest(t, "GET", prDiffURL)
+	resp := session.MakeRequest(t, req, http.StatusOK)
+	doc := NewHTMLParser(t, resp.Body)
+
+	// Assert all files are visible.
+	fileContents := doc.doc.Find(".file-content")
+	numberOfFiles := fileContents.Length()
+
+	assert.Equal(t, len(expectedFilenames), numberOfFiles)
+
+	fileContents.Each(func(i int, s *goquery.Selection) {
+		filename, _ := s.Attr("data-old-filename")
+		assert.Equal(t, expectedFilenames[i], filename)
+	})
+
+	// Ensure the review button is enabled for full PR reviews
+	assert.Equal(t, reviewBtnDisabled, doc.doc.Find(".js-btn-review").HasClass("disabled"))
+}