Add parse function, emit AST

.changeset/yellow-numbers-leave.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/compiler': minor
+---
+
+Adds support for `Astro.self` (as accepted in the [Recursive Components RFC](https://github.com/withastro/rfcs/blob/main/active-rfcs/0000-recursive-components.md)).

cmd/astro-wasm/astro-wasm.go

@@ -14,6 +14,7 @@ import (
 	"github.com/norunners/vert"
 	astro "github.com/withastro/compiler/internal"
 	"github.com/withastro/compiler/internal/printer"
+	t "github.com/withastro/compiler/internal/t"
 	"github.com/withastro/compiler/internal/transform"
 	wasm_utils "github.com/withastro/compiler/internal_wasm/utils"
 	"golang.org/x/net/html/atom"
@@ -23,6 +24,7 @@ var done chan bool
 
 func main() {
 	js.Global().Set("__astro_transform", Transform())
+	js.Global().Set("__astro_parse", Parse())
 	// This ensures that the WASM doesn't exit early
 	<-make(chan bool)
 }
@@ -41,6 +43,19 @@ func jsBool(j js.Value) bool {
 	return j.Bool()
 }
 
+func makeParseOptions(options js.Value) t.ParseOptions {
+	position := true
+
+	pos := options.Get("position")
+	if !pos.IsNull() && !pos.IsUndefined() {
+		position = pos.Bool()
+	}
+
+	return t.ParseOptions{
+		Position: position,
+	}
+}
+
 func makeTransformOptions(options js.Value, hash string) transform.TransformOptions {
 	filename := jsString(options.Get("sourcefile"))
 	if filename == "" {
@@ -107,6 +122,10 @@ type HoistedScript struct {
 	Type string `js:"type"`
 }
 
+type ParseResult struct {
+	AST string `js:"ast"`
+}
+
 type TransformResult struct {
 	Code    string          `js:"code"`
 	Map     string          `js:"map"`
@@ -133,6 +152,36 @@ func preprocessStyle(i int, style *astro.Node, transformOptions transform.Transf
 	style.FirstChild.Data = str
 }
 
+func Parse() interface{} {
+	return js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+		source := jsString(args[0])
+		parseOptions := makeParseOptions(js.Value(args[1]))
+
+		var doc *astro.Node
+		nodes, err := astro.ParseFragment(strings.NewReader(source), &astro.Node{
+			Type:     astro.ElementNode,
+			Data:     atom.Template.String(),
+			DataAtom: atom.Template,
+		})
+		if err != nil {
+			fmt.Println(err)
+		}
+		doc = &astro.Node{
+			Type: astro.DocumentNode,
+		}
+		for i := 0; i < len(nodes); i++ {
+			n := nodes[i]
+			doc.AppendChild(n)
+		}
+
+		result := printer.PrintToJSON(source, doc, parseOptions)
+
+		return vert.ValueOf(ParseResult{
+			AST: string(result.Output),
+		})
+	})
+}
+
 func Transform() interface{} {
 	return js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 		source := jsString(args[0])

go.mod

@@ -11,4 +11,6 @@ require (
 	golang.org/x/net v0.0.0-20210716203947-853a461950ff
 )
 
+require github.com/iancoleman/strcase v0.2.0 // indirect
+
 replace github.com/norunners/vert => github.com/natemoo-re/vert v0.0.0-natemoo-re.7

go.sum

@@ -1,5 +1,7 @@
 github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/iancoleman/strcase v0.2.0 h1:05I4QRnGpI0m37iZQRuskXh+w77mr6Z41lwQzuHLwW0=
+github.com/iancoleman/strcase v0.2.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
 github.com/lithammer/dedent v1.1.0 h1:VNzHMVCBNG1j0fh3OrsFRkVUwStdDArbgBWoPAffktY=
 github.com/lithammer/dedent v1.1.0/go.mod h1:jrXYCQtgg0nJiN+StA2KgR7w6CiQNv9Fd/Z9BP0jIOc=
 github.com/natemoo-re/vert v0.0.0-natemoo-re.7 h1:nhfKslS16o2Uruqt8Bwv8ZFYUuf+PW9iC2M5HI/Bs6U=

internal/const.go

@@ -4,6 +4,8 @@
 
 package astro
 
+import a "golang.org/x/net/html/atom"
+
 // Section 12.2.4.2 of the HTML5 specification says "The following elements
 // have varying levels of special parsing rules".
 // https://html.spec.whatwg.org/multipage/syntax.html#the-stack-of-open-elements
@@ -109,3 +111,26 @@ func isSpecialElement(element *Node) bool {
 	}
 	return false
 }
+
+var knownDirectiveMap = map[string]bool{
+	"client:load":    true,
+	"client:idle":    true,
+	"client:visible": true,
+	"client:only":    true,
+	"class:list":     true,
+	"set:text":       true,
+	"set:html":       true,
+}
+
+func IsKnownDirective(element *Node, attr *Attribute) bool {
+	if knownDirectiveMap[attr.Key] {
+		return true
+	}
+	if element.DataAtom == a.Script {
+		return attr.Key == "hoist"
+	}
+	if element.DataAtom == a.Style {
+		return attr.Key == "global"
+	}
+	return false
+}

internal/node.go

@@ -30,6 +30,29 @@ const (
 	ExpressionNode
 )
 
+func (t NodeType) String() string {
+	switch t {
+	case ErrorNode:
+		return "error"
+	case TextNode:
+		return "text"
+	case DocumentNode:
+		return "root"
+	case ElementNode:
+		return "element"
+	case CommentNode:
+		return "comment"
+	case DoctypeNode:
+		return "doctype"
+	case FrontmatterNode:
+		return "frontmatter"
+	case ExpressionNode:
+		return "expression"
+	default:
+		return ""
+	}
+}
+
 // Used as an Attribute Key to mark implicit nodes
 const ImplicitNodeMarker = "\x00implicit"
 

internal/parser.go

@@ -365,6 +365,7 @@ func (p *parser) addFrontmatter(empty bool) {
 		}
 		if empty {
 			p.frontmatterState = FrontmatterClosed
+			p.fm.Attr = append(p.fm.Attr, Attribute{Key: ImplicitNodeMarker, Type: EmptyAttribute})
 		} else {
 			p.frontmatterState = FrontmatterOpen
 			p.oe = append(p.oe, p.fm)

internal/printer/print-to-js.go

@@ -106,8 +106,7 @@ func render1(p *printer, n *Node, opts RenderOptions) {
 		}
 
 		p.printReturnClose()
-		// TODO: use proper component name
-		p.printFuncSuffix("$$Component")
+		p.printFuncSuffix(opts.opts)
 		return
 	}
 
@@ -149,8 +148,7 @@ func render1(p *printer, n *Node, opts RenderOptions) {
 					// 3. The metadata object
 					p.printComponentMetadata(n.Parent, opts.opts, []byte(c.Data))
 
-					// TODO: use the proper component name
-					p.printFuncPrelude("$$Component")
+					p.printFuncPrelude(opts.opts)
 				} else {
 					importStatements := c.Data[0:renderBodyStart]
 					content := c.Data[renderBodyStart:]
@@ -176,8 +174,7 @@ func render1(p *printer, n *Node, opts RenderOptions) {
 						}
 					}
 
-					// TODO: use the proper component name
-					p.printFuncPrelude("$$Component")
+					p.printFuncPrelude(opts.opts)
 					if len(c.Loc) > 0 {
 						p.addSourceMapping(loc.Loc{Start: c.Loc[0].Start + renderBodyStart})
 					}
@@ -225,8 +222,7 @@ func render1(p *printer, n *Node, opts RenderOptions) {
 		p.printTopLevelAstro(opts.opts)
 
 		// Render func prelude. Will only run for the first non-frontmatter node
-		// TODO: use the proper component name
-		p.printFuncPrelude("$$Component")
+		p.printFuncPrelude(opts.opts)
 		// This just ensures a newline
 		p.println("")