chore: enable forcetypeassert linter, fix issues (#38804)

Enable [`forcetypeassert`](https://github.com/gostaticanalysis/forcetypeassert)
linter to prevent unchecked type assertions. ~650 issues fixed, most
fixes were clean, some use `setting.PanicInDevOrTesting`.

The only behaviour changes are where code would previously send a 500 error
or panic, a 4xx error is now emitted.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/markup/markdown/math/block_parser.go

@@ -86,7 +86,7 @@ func (b *blockParser) Open(parent ast.Node, reader text.Reader, pc parser.Contex
 
 // Continue parses the current line and returns a result of parsing.
 func (b *blockParser) Continue(node ast.Node, reader text.Reader, pc parser.Context) parser.State {
-	block := node.(*Block)
+	block := node.(*Block) //nolint:forcetypeassert // this parser only ever opens *Block nodes
 	if block.Closed {
 		return parser.Close
 	}

modules/markup/markdown/math/block_renderer.go

@@ -49,7 +49,7 @@ func (r *BlockRenderer) writeLines(w util.BufWriter, source []byte, n gast.Node)
 }
 
 func (r *BlockRenderer) renderBlock(w util.BufWriter, source []byte, node gast.Node, entering bool) (gast.WalkStatus, error) {
-	n := node.(*Block)
+	n := node.(*Block) //nolint:forcetypeassert // registered for KindBlock only
 	if entering {
 		codeHTML := giteaUtil.Iif[template.HTML](n.Inline, "", `<pre class="code-block is-loading">`) + `<code class="language-math">`
 		_, _ = w.WriteString(string(r.renderInternal.ProtectSafeAttrs(codeHTML)))

modules/markup/markdown/math/inline_node.go

@@ -19,8 +19,8 @@ func (n *Inline) Inline() {}
 // IsBlank returns if this inline node is empty
 func (n *Inline) IsBlank(source []byte) bool {
 	for c := n.FirstChild(); c != nil; c = c.NextSibling() {
-		text := c.(*ast.Text).Segment
-		if !util.IsBlank(text.Value(source)) {
+		text := c.(*ast.Text) //nolint:forcetypeassert // an inline math node only holds text children
+		if !util.IsBlank(text.Segment.Value(source)) {
 			return false
 		}
 	}

modules/markup/markdown/math/inline_parser.go

@@ -160,12 +160,12 @@ func trimBlock(node *Inline, block text.Reader) {
 	}
 
 	// trim first space and last space
-	first := node.FirstChild().(*ast.Text)
+	first := node.FirstChild().(*ast.Text) //nolint:forcetypeassert // an inline math node only holds text children
 	if !(!first.Segment.IsEmpty() && block.Source()[first.Segment.Start] == ' ') {
 		return
 	}
 
-	last := node.LastChild().(*ast.Text)
+	last := node.LastChild().(*ast.Text) //nolint:forcetypeassert // an inline math node only holds text children
 	if !(!last.Segment.IsEmpty() && block.Source()[last.Segment.Stop-1] == ' ') {
 		return
 	}

modules/markup/markdown/math/inline_renderer.go

@@ -30,7 +30,7 @@ func (r *InlineRenderer) renderInline(w util.BufWriter, source []byte, n ast.Nod
 	if entering {
 		_, _ = w.WriteString(string(r.renderInternal.ProtectSafeAttrs(`<code class="language-math">`)))
 		for c := n.FirstChild(); c != nil; c = c.NextSibling() {
-			segment := c.(*ast.Text).Segment
+			segment := c.(*ast.Text).Segment //nolint:forcetypeassert // an inline math node only holds text children
 			value := util.EscapeHTML(segment.Value(source))
 			if bytes.HasSuffix(value, []byte("\n")) {
 				_, _ = w.Write(value[:len(value)-1])