Merge pull request #10 from gopherjs/scalar

Ensure that js-tagged fields are scalars

analysis/passes/embedjsobject/embedjsobject.go

@@ -39,6 +39,10 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		if _, ok := reflect.StructTag(tv).Lookup("js"); !ok {
 			return true
 		}
+		switch field.Type.(type) {
+		case *ast.ArrayType, *ast.MapType, *ast.FuncType, *ast.ChanType, *ast.StructType:
+			pass.Reportf(field.Pos(), "non-scalar types not permitted in structs that embed js.Object")
+		}
 		fieldList := findFieldList(stack)
 		for i, field := range fieldList.List {
 			if len(field.Names) > 0 {

analysis/passes/embedjsobject/testdata/src/embedjsobject/scalars.go

@@ -0,0 +1,15 @@
+package directjsobject
+
+import (
+	"github.com/gopherjs/gopherjs/js"
+)
+
+type _ struct {
+	*js.Object
+	Slice  []int       `js:"slice"`  // want "non-scalar types not permitted in structs that embed js.Object"
+	Array  [10]int     `js:"array"`  // want "non-scalar types not permitted in structs that embed js.Object"
+	Map    map[int]int `js:"map"`    // want "non-scalar types not permitted in structs that embed js.Object"
+	Func   func()      `js:"func"`   // want "non-scalar types not permitted in structs that embed js.Object"
+	Chan   chan int    `js:"chan"`   // want "non-scalar types not permitted in structs that embed js.Object"
+	Struct struct{}    `js:"struct"` // want "non-scalar types not permitted in structs that embed js.Object"
+}