fix(lint): treat an HTML comment as a text boundary outside inline elements (#1140)

* fix(lint): treat an HTML comment as a text boundary outside inline elements

An HTML comment left closedInline untouched, so clean() hit neither arm of
its whitespace rule and the following text lost its leading space. 'on
<!-- TODO --> a' fused to 'ona' and raised a false spelling alert.

Set closedInline on a comment only when no inline element is open. Inside
an open inline element the opening tag is still the boundary, so its
padding (#1052) is preserved.

Fixes #882

* test(lint): pin the inline-element case for #882

The fixture already covered a comment inside an open <em>, but the case
still asserted no output, so the regression it guards against would not
have failed the suite.

---------

Co-authored-by: VXNCXNX <VXNCXNX@users.noreply.github.com>

Author: VXNCXNX

internal/lint/ast.go

@@ -163,6 +163,13 @@ func (l *Linter) lintHTMLTokens(f *core.File, raw []byte, offset int) error { //
 				}
 			}
 		} else if tokt == html.CommentToken {
+			// A comment, like a closed inline element, is a source-faithful
+			// boundary: trust the next text's own whitespace (#882). Inside a
+			// still-open inline element the opening tag remains the boundary,
+			// so leave the state alone and keep its padding (#1052).
+			if !inline {
+				closedInline = true
+			}
 			f.UpdateComments(txt)
 			walker.update(txt, tokt)
 		} else if tokt == html.TextToken {

testdata/e2e/comments.yaml

@@ -100,3 +100,12 @@ cases:
     exit: 0
     want: |
       issue1001.md:5:28:demo.Ending-Preposition:Don't end a sentence with 'of.'
+
+  - name: inline-comment-spacing
+    about: "#882 -- text after a comment keeps its own leading space instead of
+      fusing with the text before it; inside a still-open inline element the
+      opening tag stays the boundary, so `sona` isn't fused into `sonata`"
+    args: issue882.md
+    exit: 1
+    want: |
+      issue882.md:4:3:Vale.Spelling:Did you really mean 'sona'?

testdata/fixtures/comments/.vale.ini

@@ -12,3 +12,6 @@ demo.SentenceCaseAny = NO
 
 [test2.mdx]
 CommentDelimiters = {/*, */}
+
+[issue882.md]
+BasedOnStyles = Vale

testdata/fixtures/comments/issue882.md

@@ -0,0 +1,4 @@
+on <!-- TODO --> a
+sonata
+
+A sona<em><!--c-->ta</em> here.