feat: support parsing (and converting) void elements, fixes #637 (#732)

.version

@@ -1 +1 @@
-0.2.682
+0.2.683

README.md

@@ -76,6 +76,16 @@ go run ./cmd/templ generate -include-version=false
 go test ./...
 ```
 
+### test-short
+
+Run Go tests.
+
+```sh
+go run ./get-version > .version
+go run ./cmd/templ generate -include-version=false
+go test ./... -short
+```
+
 ### test-cover
 
 Run Go tests.

generator/generator.go

@@ -880,46 +880,6 @@ func (g *generator) writeExpressionErrorHandler(indentLevel int, expression pars
 }
 
 func (g *generator) writeElement(indentLevel int, n parser.Element) (err error) {
-	if n.IsVoidElement() {
-		return g.writeVoidElement(indentLevel, n)
-	}
-	return g.writeStandardElement(indentLevel, n)
-}
-
-func (g *generator) writeVoidElement(indentLevel int, n parser.Element) (err error) {
-	if len(n.Children) > 0 {
-		return fmt.Errorf("writeVoidElement: void element %q must not have child elements", n.Name)
-	}
-	if len(n.Attributes) == 0 {
-		// <br>
-		if _, err = g.w.WriteStringLiteral(indentLevel, fmt.Sprintf(`<%s>`, html.EscapeString(n.Name))); err != nil {
-			return err
-		}
-	} else {
-		// <style type="text/css"></style>
-		if err = g.writeElementCSS(indentLevel, n); err != nil {
-			return err
-		}
-		// <script type="text/javascript"></script>
-		if err = g.writeElementScript(indentLevel, n); err != nil {
-			return err
-		}
-		// <hr
-		if _, err = g.w.WriteStringLiteral(indentLevel, fmt.Sprintf(`<%s`, html.EscapeString(n.Name))); err != nil {
-			return err
-		}
-		if err = g.writeElementAttributes(indentLevel, n.Name, n.Attributes); err != nil {
-			return err
-		}
-		// >
-		if _, err = g.w.WriteStringLiteral(indentLevel, `>`); err != nil {
-			return err
-		}
-	}
-	return err
-}
-
-func (g *generator) writeStandardElement(indentLevel int, n parser.Element) (err error) {
 	if len(n.Attributes) == 0 {
 		// <div>
 		if _, err = g.w.WriteStringLiteral(indentLevel, fmt.Sprintf(`<%s>`, html.EscapeString(n.Name))); err != nil {
@@ -946,6 +906,10 @@ func (g *generator) writeStandardElement(indentLevel int, n parser.Element) (err
 			return err
 		}
 	}
+	// Skip children and close tag for void elements.
+	if n.IsVoidElement() && len(n.Children) == 0 {
+		return nil
+	}
 	// Children.
 	if err = g.writeNodes(indentLevel, stripWhitespace(n.Children), nil); err != nil {
 		return err

generator/test-html/expected.html

@@ -8,4 +8,4 @@ <h1>Luiz Bonfa</h1>
 <hr noshade>
 <hr optionA optionB optionC="other">
 <hr noshade>
-
+<input name="test">Text</input>

generator/test-html/template.templ

@@ -10,4 +10,5 @@ templ render(p person) {
 	<hr noshade?={ true }/>
 	<hr optionA optionB?={ true } optionC="other" optionD?={ false }/>
 	<hr noshade/>
+	<input name="test">Text</input>
 }

parser/v2/diagnostics.go

@@ -1,6 +1,9 @@
 package parser
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 type diagnoser func(Node) ([]Diagnostic, error)
 
@@ -30,10 +33,12 @@ func walkNodes(t []Node, f func(Node) bool) {
 	}
 }
 
+var diagnosers = []diagnoser{
+	useOfLegacyCallSyntaxDiagnoser,
+	voidElementWithChildrenDiagnoser,
+}
+
 func Diagnose(t TemplateFile) ([]Diagnostic, error) {
-	diagnosers := []diagnoser{
-		legacyCallSyntaxDiagnoser,
-	}
 	var diags []Diagnostic
 	var errs error
 	walkTemplate(t, func(n Node) bool {
@@ -50,7 +55,7 @@ func Diagnose(t TemplateFile) ([]Diagnostic, error) {
 	return diags, errs
 }
 
-func legacyCallSyntaxDiagnoser(n Node) ([]Diagnostic, error) {
+func useOfLegacyCallSyntaxDiagnoser(n Node) ([]Diagnostic, error) {
 	if c, ok := n.(CallTemplateExpression); ok {
 		return []Diagnostic{{
 			Message: "`{! foo }` syntax is deprecated. Use `@foo` syntax instead. Run `templ fmt .` to fix all instances.",
@@ -59,3 +64,20 @@ func legacyCallSyntaxDiagnoser(n Node) ([]Diagnostic, error) {
 	}
 	return nil, nil
 }
+
+func voidElementWithChildrenDiagnoser(n Node) (d []Diagnostic, err error) {
+	e, ok := n.(Element)
+	if !ok {
+		return
+	}
+	if !e.IsVoidElement() {
+		return
+	}
+	if len(e.Children) == 0 {
+		return
+	}
+	return []Diagnostic{{
+		Message: fmt.Sprintf("void element <%s> should not have child content", e.Name),
+		Range:   e.NameRange,
+	}}, nil
+}

parser/v2/diagnostics_test.go

@@ -23,10 +23,10 @@ templ template () {
 			want: nil,
 		},
 
-		// legacyCallSyntaxDiagnoser
+		// useOfLegacyCallSyntaxDiagnoser
 
 		{
-			name: "legacyCallSyntaxDiagnoser: template root",
+			name: "useOfLegacyCallSyntaxDiagnoser: template root",
 			template: `
 package main
 
@@ -39,7 +39,7 @@ templ template () {
 			}},
 		},
 		{
-			name: "legacyCallSyntaxDiagnoser: in div",
+			name: "useOfLegacyCallSyntaxDiagnoser: in div",
 			template: `
 package main
 
@@ -54,7 +54,7 @@ templ template () {
 			}},
 		},
 		{
-			name: "legacyCallSyntaxDiagnoser: in if",
+			name: "useOfLegacyCallSyntaxDiagnoser: in if",
 			template: `
 package main
 
@@ -69,7 +69,7 @@ templ template () {
 			}},
 		},
 		{
-			name: "legacyCallSyntaxDiagnoser: in for",
+			name: "useOfLegacyCallSyntaxDiagnoser: in for",
 			template: `
 package main
 
@@ -84,7 +84,7 @@ templ template () {
 			}},
 		},
 		{
-			name: "legacyCallSyntaxDiagnoser: in switch",
+			name: "useOfLegacyCallSyntaxDiagnoser: in switch",
 			template: `
 package main
 
@@ -108,7 +108,7 @@ templ template () {
 			},
 		},
 		{
-			name: "legacyCallSyntaxDiagnoser: in block",
+			name: "useOfLegacyCallSyntaxDiagnoser: in block",
 			template: `
 package main
 
@@ -122,6 +122,33 @@ templ template () {
 				Range:   Range{Position{59, 5, 5}, Position{75, 5, 21}},
 			}},
 		},
+		{
+			name: "voidElementWithChildrenDiagnoser: no diagnostics",
+			template: `
+package main
+
+templ template () {
+	<div>
+		<input/>
+	</div>
+}`,
+			want: nil,
+		},
+		{
+			name: "voidElementWithChildrenDiagnoser: with diagnostics",
+			template: `
+package main
+
+templ template () {
+	<div>
+	  <input>Child content</input>
+	</div>
+}`,
+			want: []Diagnostic{{
+				Message: "void element <input> should not have child content",
+				Range:   Range{Position{46, 5, 4}, Position{51, 5, 9}},
+			}},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -133,7 +160,7 @@ templ template () {
 			if err != nil {
 				t.Fatalf("Diagnose() error = %v", err)
 			}
-			if diff := cmp.Diff(got, tt.want); diff != "" {
+			if diff := cmp.Diff(tt.want, got); diff != "" {
 				t.Errorf("Diagnose() mismatch (-got +want):\n%s", diff)
 			}
 		})