[#95] Support HTML tag parsing compatible with HTML spec

Problem: We had hardcoded HTML tag parser, that doesn't work with add valid HTML tags

Solution: Replace it with `tagsoup` library, that care about all parsing stuff

package.yaml

@@ -101,6 +101,7 @@ library:
     - regex-tdfa
     - req
     - roman-numerals
+    - tagsoup
     - text
     - text-metrics
     - th-lift-instances

src/Xrefcheck/Scanners/Markdown.hs

@@ -26,6 +26,7 @@ import Data.Default (def)
 import Data.Text qualified as T
 import Data.Text.Lazy qualified as LT
 import Fmt (Buildable (..), blockListF, nameF, (+|), (|+))
+import Text.HTML.TagSoup
 
 import Xrefcheck.Core
 import Xrefcheck.Scan
@@ -146,7 +147,16 @@ nodeExtractInfo input@(Node _ _ nSubs) = do
           return $ FileInfoDiff DList.empty $ DList.singleton $ Anchor {aType, aName, aPos}
 
         HTML_INLINE text -> do
-          let mName = T.stripSuffix "\">" =<< T.stripPrefix "<a name=\"" text
+          let
+            mName = do
+              tag <- safeHead $ parseTags text
+              attributes <- case tag of
+                TagOpen a attrs
+                  | T.toLower a == "a" -> Just attrs
+                _ -> Nothing
+              (_, name) <- find (\(field, _) -> T.toLower field == "name") attributes
+              pure name
+
           case mName of
             Just aName -> do
               let aType = HandAnchor

tests/golden/check-html/check-html.md

@@ -0,0 +1,13 @@
+<!--
+ - SPDX-FileCopyrightText: 2022 Serokell <https://serokell.io>
+ -
+ - SPDX-License-Identifier: MPL-2.0
+ -->
+
+## <a name='one'> <a name=two> <a NAME="three"> <a name="four"></a> <a     NAME=five   >  Title1
+
+[One](#one)
+[Two](#two)
+[Three](#three)
+[Four](#four)
+[Five](#five)

tests/golden/check-html/check.html.bats

@@ -0,0 +1,16 @@
+#!/usr/bin/env bats
+
+# SPDX-FileCopyrightText: 2022 Serokell <https://serokell.io>
+#
+# SPDX-License-Identifier: MPL-2.0
+
+load '../helpers/bats-support/load'
+load '../helpers/bats-assert/load'
+load '../helpers'
+
+
+@test "All HTML anchors should be valid" {
+  run xrefcheck
+
+  assert_output --partial "All repository links are valid."
+}