Merge pull request #32 from gobuffalo/fix-for-loop-error-numbers

Line numbers for errors are wrongly reported inside of for loops fixes #30

compiler.go

@@ -17,6 +17,7 @@ var ErrUnknownIdentifier = errors.New("unknown identifier")
 type compiler struct {
 	ctx     *Context
 	program *ast.Program
+	curStmt ast.Statement
 }
 
 func (c *compiler) compile() (string, error) {
@@ -37,7 +38,11 @@ func (c *compiler) compile() (string, error) {
 			res, err = c.evalLetStatement(node)
 		}
 		if err != nil {
-			return "", errors.WithStack(errors.Wrapf(err, "line %d", stmt.T().LineNumber))
+			s := stmt
+			if c.curStmt != nil {
+				s = c.curStmt
+			}
+			return "", errors.WithStack(errors.Wrapf(err, "line %d", s.T().LineNumber))
 		}
 
 		c.write(bb, res)
@@ -239,6 +244,9 @@ func (c *compiler) evalIdentifier(node *ast.Identifier) (interface{}, error) {
 		if rv.Kind() == reflect.Ptr {
 			rv = rv.Elem()
 		}
+		if rv.Kind() != reflect.Struct {
+			return nil, errors.WithStack(errors.Errorf("'%s' does not have a field or method named '%s' (%s)", node.Callee.String(), node.Value, node))
+		}
 		f := rv.FieldByName(node.Value)
 		if !f.IsValid() {
 			m := rv.MethodByName(node.Value)
@@ -665,6 +673,7 @@ func (c *compiler) evalBlockStatement(node *ast.BlockStatement) (interface{}, er
 }
 
 func (c *compiler) evalStatement(node ast.Statement) (interface{}, error) {
+	c.curStmt = node
 	// fmt.Println("evalStatement")
 	switch t := node.(type) {
 	case *ast.ExpressionStatement:

plush_test.go

@@ -410,6 +410,44 @@ func Test_VariadicHelperWithWrongParam(t *testing.T) {
 	r.Contains(err.Error(), "test (string) is an invalid argument for foo at pos 2: expected (int)")
 }
 
+func Test_LineNumberErrors(t *testing.T) {
+	r := require.New(t)
+	input := `<p>
+	<%= f.Foo %>
+</p>`
+
+	_, err := Render(input, NewContext())
+	r.Error(err)
+	r.Contains(err.Error(), "line 2:")
+}
+
+func Test_LineNumberErrors_ForLoop(t *testing.T) {
+	r := require.New(t)
+	input := `
+	<%= for (n) in numbers.Foo { %>
+		<%= n %>
+	<% } %>
+	`
+
+	_, err := Render(input, NewContext())
+	r.Error(err)
+	r.Contains(err.Error(), "line 2:")
+}
+
+func Test_LineNumberErrors_InsideForLoop(t *testing.T) {
+	r := require.New(t)
+	input := `
+	<%= for (n) in numbers { %>
+		<%= n.Foo %>
+	<% } %>
+	`
+	ctx := NewContext()
+	ctx.Set("numbers", []int{1, 2})
+	_, err := Render(input, ctx)
+	r.Error(err)
+	r.Contains(err.Error(), "line 3:")
+}
+
 func Test_RunScript(t *testing.T) {
 	r := require.New(t)
 	bb := &bytes.Buffer{}