Test renderReadmeFile (go-gitea#23185)

Add test coverage to the important features of
[`routers.web.repo.renderReadmeFile`](https://github.com/go-gitea/gitea/blob/067b0c2664d127c552ccdfd264257caca4907a77/routers/web/repo/view.go#L273);
namely that:

- it can handle looking in docs/, .gitea/, and .github/
- it can handle choosing between multiple competing READMEs
- it prefers the localized README to the markdown README to the
plaintext README
- it can handle broken symlinks when processing all the options
- it uses the name of the symlink, not the name of the target of the
symlink

models/db/iterate_test.go

@@ -25,7 +25,7 @@ func TestIterate(t *testing.T) {
 		return nil
 	})
 	assert.NoError(t, err)
-	assert.EqualValues(t, 83, repoCnt)
+	assert.EqualValues(t, 84, repoCnt)
 
 	err = db.Iterate(db.DefaultContext, nil, func(ctx context.Context, repoUnit *repo_model.RepoUnit) error {
 		reopUnit2 := repo_model.RepoUnit{ID: repoUnit.ID}

models/db/list_test.go

@@ -35,11 +35,11 @@ func TestFind(t *testing.T) {
 	var repoUnits []repo_model.RepoUnit
 	err := db.Find(db.DefaultContext, &opts, &repoUnits)
 	assert.NoError(t, err)
-	assert.EqualValues(t, 83, len(repoUnits))
+	assert.EqualValues(t, 84, len(repoUnits))
 
 	cnt, err := db.Count(db.DefaultContext, &opts, new(repo_model.RepoUnit))
 	assert.NoError(t, err)
-	assert.EqualValues(t, 83, cnt)
+	assert.EqualValues(t, 84, cnt)
 
 	repoUnits = make([]repo_model.RepoUnit, 0, 10)
 	newCnt, err := db.FindAndCount(db.DefaultContext, &opts, &repoUnits)

models/fixtures/repo_unit.yml

@@ -569,3 +569,9 @@
   type: 3
   config: "{\"IgnoreWhitespaceConflicts\":false,\"AllowMerge\":true,\"AllowRebase\":true,\"AllowRebaseMerge\":true,\"AllowSquash\":true}"
   created_unix: 946684810
+
+-
+  id: 84
+  repo_id: 56
+  type: 1
+  created_unix: 946684810

models/fixtures/repository.yml

@@ -1634,3 +1634,16 @@
   is_private: true
   num_issues: 1
   status: 0
+
+-
+  id: 56
+  owner_id: 2
+  owner_name: user2
+  lower_name: readme-test
+  name: readme-test
+  default_branch: master
+  is_empty: false
+  is_archived: false
+  is_private: true
+  status: 0
+  num_issues: 0

models/fixtures/user.yml

@@ -66,7 +66,7 @@
   num_followers: 2
   num_following: 1
   num_stars: 2
-  num_repos: 11
+  num_repos: 12
   num_teams: 0
   num_members: 0
   visibility: 0

tests/gitea-repositories-meta/user2/readme-test.git/HEAD

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

tests/gitea-repositories-meta/user2/readme-test.git/config

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

tests/gitea-repositories-meta/user2/readme-test.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/readme-test.git/info/refs

@@ -0,0 +1,21 @@
+ea9ef877d1d88af76682d8798418081264f10cfc	refs/heads/fallbacks
+0d4c14db927c9ffba01fa7e126cc748b5c02c01e	refs/heads/fallbacks2
+c66d5b07c2063d3268707f22226c708b589574ef	refs/heads/fallbacks3
+89f8426e9eb5eff35c09b3565836c8f8e15d0ce9	refs/heads/fallbacks4
+b0e902496eae435ad03c92a5d479f916ef2d4893	refs/heads/fallbacks5
+84a5500b5cc040b11daf53fc42c542a99589dc76	refs/heads/fallbacks6
+cf406a96e416d7de5c4c1bbfffdd672300c822bf	refs/heads/fallbacks7
+0d6ac644b969e9199915a492da9dba08c179fd23	refs/heads/fallbacks8
+5038febc0c57215beb3748d7ae4091a25a4acc93	refs/heads/fallbacks9
+9134e1f178ca4cccf1a197142646f2d7627e8cd5	refs/heads/i18n
+744d2441e55bc0010d6b340d303f0106a627ad29	refs/heads/master
+3c492566170b057e962c025515ab38bbd7444077	refs/heads/plain
+3882d6373a0882a6739b3cd9b24d21c630621234	refs/heads/sp-ace
+bf5ed898252eaa50dcc01108ed4417c3ea98a294	refs/heads/special-subdir-.gitea
+c03543573ab088ce1cf7090a387d2be621426234	refs/heads/special-subdir-.github
+e75957ad9b7e6ed16dda183529ec283db0bbc5fe	refs/heads/special-subdir-docs
+46f5d5ab33d701642e08c713fab42af89fdd4fea	refs/heads/special-subdir-nested
+9c0f872256b839c2b97ec22fd348d87b14045513	refs/heads/subdir
+d7a854fff61e45b98234d7aa79ecbcb1619cd3dd	refs/heads/symlink
+30b9c0ed4b1039dbd99f3fb537b84ca507e0549d	refs/heads/symlink-loop
+41489b7be5c2244d2b7b524dcb31caf3bd1f9ccc	refs/heads/txt

tests/gitea-repositories-meta/user2/readme-test.git/objects/21/470f9b3e8ff24e0fa083d2dbc447f4c3401355

@@ -0,0 +1,2 @@
+x
��;�0@�s
+_�*N��H��1q
�u(�?�t��T�0��==���Q��+�*4��d��h�S�η.z���͙Z3�c
t��0'�As�5h�zL�=D��B�\cx-ݴ��!O������q�����<�����	0�T�装���5�=-�����U s�7,O�
#�M�

tests/gitea-repositories-meta/user2/readme-test.git/objects/3b/23d7f1a9cb904cb46f5f2272bfa5ed5f871fb9

@@ -0,0 +1 @@
+x
��M� �aל��0&Ƹs��ئ�'�.���x������4]���.)�D��Q�|@b6Xbd��}�2+b�%�T� �I>g�	2�7Q���. (c�����"o��n�M�<�[6�_^橼�Z��T�U�� ���n��qO�*3��{���N\

tests/gitea-repositories-meta/user2/readme-test.git/objects/60/ea618ae7d4ecbe9c1962591c7da1b05bb1a5c8

@@ -0,0 +1,3 @@
+x
��;�0@�s
+_�*N뤕bcc���Њ�Tҁ�S!N�����d�>���!���քLu�Ul�#q����l�Q�,�ꔡ��lCBn$6��X�Dɹ�bbҖR0���y�[/O�n���
+�i�����2�1��Ї@�e�p�d���iޭ�殯��!�<���N�

tests/gitea-repositories-meta/user2/readme-test.git/objects/e3/a6fd8fe49e323ee10017f72b777a53fbd8076f

@@ -0,0 +1,3 @@
+x
��M
+1�a�=E.��m�� �Νwh����#�"��A<��g�~|eǾ�#�jU:����$%�9o��{�9F	�գQdsOU��H��rA�(�=�x��E���$nkҳ]�
+�����\ҫV�M7��yx�mؔ��1�-�1 ��}ږ��3�/�%=�f>&L�

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

@@ -0,0 +1,2 @@
+P pack-8933bd634b76f8154310cccb52537a0195e43166.pack
+

tests/gitea-repositories-meta/user2/readme-test.git/packed-refs

@@ -0,0 +1,22 @@
+# pack-refs with: peeled fully-peeled sorted 
+ea9ef877d1d88af76682d8798418081264f10cfc refs/heads/fallbacks
+0d4c14db927c9ffba01fa7e126cc748b5c02c01e refs/heads/fallbacks2
+c66d5b07c2063d3268707f22226c708b589574ef refs/heads/fallbacks3
+89f8426e9eb5eff35c09b3565836c8f8e15d0ce9 refs/heads/fallbacks4
+b0e902496eae435ad03c92a5d479f916ef2d4893 refs/heads/fallbacks5
+84a5500b5cc040b11daf53fc42c542a99589dc76 refs/heads/fallbacks6
+cf406a96e416d7de5c4c1bbfffdd672300c822bf refs/heads/fallbacks7
+0d6ac644b969e9199915a492da9dba08c179fd23 refs/heads/fallbacks8
+5038febc0c57215beb3748d7ae4091a25a4acc93 refs/heads/fallbacks9
+9134e1f178ca4cccf1a197142646f2d7627e8cd5 refs/heads/i18n
+744d2441e55bc0010d6b340d303f0106a627ad29 refs/heads/master
+3c492566170b057e962c025515ab38bbd7444077 refs/heads/plain
+3882d6373a0882a6739b3cd9b24d21c630621234 refs/heads/sp-ace
+bf5ed898252eaa50dcc01108ed4417c3ea98a294 refs/heads/special-subdir-.gitea
+c03543573ab088ce1cf7090a387d2be621426234 refs/heads/special-subdir-.github
+e75957ad9b7e6ed16dda183529ec283db0bbc5fe refs/heads/special-subdir-docs
+46f5d5ab33d701642e08c713fab42af89fdd4fea refs/heads/special-subdir-nested
+9c0f872256b839c2b97ec22fd348d87b14045513 refs/heads/subdir
+d7a854fff61e45b98234d7aa79ecbcb1619cd3dd refs/heads/symlink
+30b9c0ed4b1039dbd99f3fb537b84ca507e0549d refs/heads/symlink-loop
+41489b7be5c2244d2b7b524dcb31caf3bd1f9ccc refs/heads/txt

tests/gitea-repositories-meta/user2/readme-test.git/refs/heads/fallbacks-broken-symlinks

@@ -0,0 +1 @@
+fe495ea336f079ef2bed68648d0ba9a37cdbd4aa

tests/integration/repo_test.go

@@ -257,6 +257,111 @@ func TestViewRepoDirectory(t *testing.T) {
 	assert.Zero(t, repoSummary.Length())
 }
 
+// ensure that the all the different ways to find and render a README work
+func TestViewRepoDirectoryReadme(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// there are many combinations:
+	// - READMEs can be .md, .txt, or have no extension
+	// - READMEs can be tagged with a language and even a country code
+	// - READMEs can be stored in docs/, .gitea/, or .github/
+	// - READMEs can be symlinks to other files
+	// - READMEs can be broken symlinks which should not render
+	//
+	// this doesn't cover all possible cases, just the major branches of the code
+
+	session := loginUser(t, "user2")
+
+	check := func(name, url, expectedFilename, expectedReadmeType, expectedContent string) {
+		t.Run(name, func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			req := NewRequest(t, "GET", url)
+			resp := session.MakeRequest(t, req, http.StatusOK)
+
+			htmlDoc := NewHTMLParser(t, resp.Body)
+			readmeName := htmlDoc.doc.Find("h4.file-header")
+			readmeContent := htmlDoc.doc.Find(".file-view") // TODO: add a id="readme" to the output to make this test more precise
+			readmeType, _ := readmeContent.Attr("class")
+
+			assert.Equal(t, expectedFilename, strings.TrimSpace(readmeName.Text()))
+			assert.Contains(t, readmeType, expectedReadmeType)
+			assert.Contains(t, readmeContent.Text(), expectedContent)
+		})
+	}
+
+	// viewing the top level
+	check("Home", "/user2/readme-test/", "README.md", "markdown", "The cake is a lie.")
+
+	// viewing different file extensions
+	check("md", "/user2/readme-test/src/branch/master/", "README.md", "markdown", "The cake is a lie.")
+	check("txt", "/user2/readme-test/src/branch/txt/", "README.txt", "plain-text", "My spoon is too big.")
+	check("plain", "/user2/readme-test/src/branch/plain/", "README", "plain-text", "Birken my stocks gee howdy")
+	check("i18n", "/user2/readme-test/src/branch/i18n/", "README.zh.md", "markdown", "蛋糕是一个谎言")
+
+	// viewing different subdirectories
+	check("subdir", "/user2/readme-test/src/branch/subdir/libcake", "README.md", "markdown", "Four pints of sugar.")
+	check("docs-direct", "/user2/readme-test/src/branch/special-subdir-docs/docs/", "README.md", "markdown", "This is in docs/")
+	check("docs", "/user2/readme-test/src/branch/special-subdir-docs/", "docs/README.md", "markdown", "This is in docs/")
+	check(".gitea", "/user2/readme-test/src/branch/special-subdir-.gitea/", ".gitea/README.md", "markdown", "This is in .gitea/")
+	check(".github", "/user2/readme-test/src/branch/special-subdir-.github/", ".github/README.md", "markdown", "This is in .github/")
+
+	// symlinks
+	// symlinks are subtle:
+	// - they should be able to handle going a reasonable number of times up and down in the tree
+	// - they shouldn't get stuck on link cycles
+	// - they should determine the filetype based on the name of the link, not the target
+	check("symlink", "/user2/readme-test/src/branch/symlink/", "README.md", "markdown", "This is in some/other/path")
+	check("symlink-multiple", "/user2/readme-test/src/branch/symlink/some/", "README.txt", "plain-text", "This is in some/other/path")
+	check("symlink-up-and-down", "/user2/readme-test/src/branch/symlink/up/back/down/down", "README.md", "markdown", "It's a me, mario")
+
+	// testing fallback rules
+	// READMEs are searched in this order:
+	// - [README.zh-cn.md, README.zh_cn.md, README.zh.md, README_zh.md, README.md, README.txt, README,
+	//     docs/README.zh-cn.md, docs/README.zh_cn.md, docs/README.zh.md, docs/README_zh.md, docs/README.md, docs/README.txt, docs/README,
+	//    .gitea/README.zh-cn.md, .gitea/README.zh_cn.md, .gitea/README.zh.md, .gitea/README_zh.md, .gitea/README.md, .gitea/README.txt, .gitea/README,
+
+	//     .github/README.zh-cn.md, .github/README.zh_cn.md, .github/README.zh.md, .github/README_zh.md, .github/README.md, .github/README.txt, .github/README]
+	// and a broken/looped symlink counts as not existing at all and should be skipped.
+	// again, this doesn't cover all cases, but it covers a few
+	check("fallback/top", "/user2/readme-test/src/branch/fallbacks/", "README.en.md", "markdown", "This is README.en.md")
+	check("fallback/2", "/user2/readme-test/src/branch/fallbacks2/", "README.md", "markdown", "This is README.md")
+	check("fallback/3", "/user2/readme-test/src/branch/fallbacks3/", "README", "plain-text", "This is README")
+	check("fallback/4", "/user2/readme-test/src/branch/fallbacks4/", "docs/README.en.md", "markdown", "This is docs/README.en.md")
+	check("fallback/5", "/user2/readme-test/src/branch/fallbacks5/", "docs/README.md", "markdown", "This is docs/README.md")
+	check("fallback/6", "/user2/readme-test/src/branch/fallbacks6/", "docs/README", "plain-text", "This is docs/README")
+	check("fallback/7", "/user2/readme-test/src/branch/fallbacks7/", ".gitea/README.en.md", "markdown", "This is .gitea/README.en.md")
+	check("fallback/8", "/user2/readme-test/src/branch/fallbacks8/", ".gitea/README.md", "markdown", "This is .gitea/README.md")
+	check("fallback/9", "/user2/readme-test/src/branch/fallbacks9/", ".gitea/README", "plain-text", "This is .gitea/README")
+
+	// this case tests that broken symlinks count as missing files, instead of rendering their contents
+	check("fallbacks-broken-symlinks", "/user2/readme-test/src/branch/fallbacks-broken-symlinks/", "docs/README", "plain-text", "This is docs/README")
+
+	// some cases that should NOT render a README
+	// - /readme
+	// - /.github/docs/README.md
+	// - a symlink loop
+
+	missing := func(name, url string) {
+		t.Run("missing/"+name, func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			req := NewRequest(t, "GET", url)
+			resp := session.MakeRequest(t, req, http.StatusOK)
+
+			htmlDoc := NewHTMLParser(t, resp.Body)
+			_, exists := htmlDoc.doc.Find(".file-view").Attr("class")
+			fmt.Printf("%s", resp.Body)
+
+			assert.False(t, exists, "README should not have rendered")
+		})
+	}
+	missing("sp-ace", "/user2/readme-test/src/branch/sp-ace/")
+	missing("nested-special", "/user2/readme-test/src/branch/special-subdir-nested/subproject") // the special subdirs should only trigger on the repo root
+	// missing("special-subdir-nested", "/user2/readme-test/src/branch/special-subdir-nested/") // This is currently FAILING, due to a bug introduced in https://github.com/go-gitea/gitea/pull/22177
+	missing("symlink-loop", "/user2/readme-test/src/branch/symlink-loop/")
+}
+
 func TestMarkDownImage(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()