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/goldmark.go

@@ -43,8 +43,8 @@ func (g *ASTTransformer) applyElementDir(n ast.Node) {
 // Transform transforms the given AST tree.
 func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
 	firstChild := node.FirstChild()
-	ctx := pc.Get(renderContextKey).(*markup.RenderContext)
-	rc := pc.Get(renderConfigKey).(*RenderConfig)
+	ctx := pc.Get(renderContextKey).(*markup.RenderContext) //nolint:forcetypeassert // the renderer always seeds this key before parsing
+	rc := pc.Get(renderConfigKey).(*RenderConfig)           //nolint:forcetypeassert // the renderer always seeds this key before parsing
 
 	tocMode := ""
 	if rc.yamlNode != nil {
@@ -150,9 +150,7 @@ func (r *HTMLRenderer) renderCodeBlock(w util.BufWriter, source []byte, n ast.No
 }
 
 func (r *HTMLRenderer) renderDocument(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
-	n := node.(*ast.Document)
-
-	if val, has := n.AttributeString("lang"); has {
+	if val, has := node.AttributeString("lang"); has {
 		var err error
 		if entering {
 			_, err = w.WriteString("<div")
@@ -212,7 +210,7 @@ func (r *HTMLRenderer) renderRawHTML(w util.BufWriter, source []byte, node ast.N
 	if !entering {
 		return ast.WalkContinue, nil
 	}
-	n := node.(*RawHTML)
+	n := node.(*RawHTML) //nolint:forcetypeassert // registered for KindRawHTML only
 	_, err := w.WriteString(string(r.renderInternal.ProtectSafeAttrs(n.rawHTML)))
 	if err != nil {
 		return ast.WalkStop, err

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])

modules/markup/markdown/transform_blockquote.go

@@ -18,7 +18,7 @@ import (
 // renderAttention renders a quote marked with i.e. "> **Note**" or "> [!Warning]" with a corresponding svg
 func (r *HTMLRenderer) renderAttention(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
 	if entering {
-		n := node.(*Attention)
+		n := node.(*Attention) //nolint:forcetypeassert // registered for KindAttention only
 		var octiconName string
 		switch n.AttentionType {
 		case "tip":

modules/markup/markdown/transform_list.go

@@ -15,7 +15,7 @@ import (
 )
 
 func (r *HTMLRenderer) renderTaskCheckBoxListItem(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
-	n := node.(*TaskCheckBoxListItem)
+	n := node.(*TaskCheckBoxListItem) //nolint:forcetypeassert // registered for KindTaskCheckBoxListItem only
 	if entering {
 		if n.Attributes() != nil {
 			_, _ = w.WriteString("<li")
@@ -60,7 +60,7 @@ func (g *ASTTransformer) transformList(_ *markup.RenderContext, v *ast.List, rc
 		v.RemoveChildren(v)
 
 		for _, child := range children {
-			listItem := child.(*ast.ListItem)
+			listItem := child.(*ast.ListItem) //nolint:forcetypeassert // a list only holds list items
 			if !child.HasChildren() || !child.FirstChild().HasChildren() {
 				v.AppendChild(v, child)
 				continue