shader: Add more tests

internal/shader/shader.go

@@ -303,6 +303,7 @@ func (sh *Shader) parseFunc(d *ast.FuncDecl, block *block) function {
 	}
 
 	var rets []variable
+	if d.Type.Results != nil {
 		for _, f := range d.Type.Results.List {
 			t := parseType(f.Type)
 			if t == typNone {
@@ -323,6 +324,7 @@ func (sh *Shader) parseFunc(d *ast.FuncDecl, block *block) function {
 				}
 			}
 		}
+	}
 
 	return function{
 		name: d.Name.Name,
@@ -397,7 +399,11 @@ func (s *Shader) detectType(b *block, expr ast.Expr) typ {
 		if e.Kind == token.FLOAT {
 			return typFloat
 		}
+		if e.Kind == token.INT {
+			s.addError(expr.Pos(), fmt.Sprintf("integer literal is not implemented yet: %s", e.Value))
+		} else {
 			s.addError(expr.Pos(), fmt.Sprintf("unexpected literal: %s", e.Value))
+		}
 		return typNone
 	case *ast.CompositeLit:
 		return parseType(e.Type)
@@ -425,7 +431,9 @@ func (s *Shader) detectType(b *block, expr ast.Expr) typ {
 func (s *Shader) Dump() string {
 	var lines []string
 
+	if s.position.name != "" {
 		lines = append(lines, fmt.Sprintf("var %s varying %s // position", s.position.name, s.position.typ))
+	}
 	for _, v := range s.varyings {
 		lines = append(lines, fmt.Sprintf("var %s varying %s", v.name, v.typ))
 	}

internal/shader/shader_test.go

@@ -23,12 +23,12 @@ import (
 func TestDump(t *testing.T) {
 	tests := []struct {
 		Name string
-		In   string
+		Src  string
 		Dump string
 	}{
 		{
 			Name: "general",
-			In: `package main
+			Src: `package main
 
 type VertexOut struct {
 	Position vec4 ` + "`kage:\"position\"`" + `
@@ -74,11 +74,27 @@ func F1(a vec2, b vec2) (_ vec4) {
 	c3 = vec4{c0, c1}
 	return c2
 }
+`,
+		},
+		{
+			Name: "Type",
+			Src:  `package main
+
+var c0 = 0.0
+func F() {
+	c1 := c0
+}
+`,
+			Dump: `var c0 float = 0.0
+func F() {
+	var c1 float
+	c1 = c0
+}
 `,
 		},
 	}
 	for _, tc := range tests {
-		s, err := NewShader([]byte(tc.In))
+		s, err := NewShader([]byte(tc.Src))
 		if err != nil {
 			t.Error(err)
 			continue