Add more tests

Author: antonmedv

eval.go

@@ -11,23 +11,22 @@ type evaluator interface {
 }
 
 // Eval parses and evaluates given input.
-func Eval(input string, env interface{}) (node interface{}, err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			err = fmt.Errorf("%v", r)
-		}
-	}()
-
-	node, err = Parse(input)
-
+func Eval(input string, env interface{}) (interface{}, error) {
+	node, err := Parse(input)
 	if err != nil {
 		return nil, err
 	}
 	return Run(node, env)
 }
 
 // Run evaluates given ast.
-func Run(node Node, env interface{}) (interface{}, error) {
+func Run(node Node, env interface{}) (out interface{}, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
 	if e, ok := node.(evaluator); ok {
 		return e.eval(env)
 	}

eval_test.go

@@ -429,3 +429,20 @@ func TestEvalComplex(t *testing.T) {
 		t.Fatalf("TestEvalComplex:\ngot\n\t%#v\nexpected:\n\t%#v", actual, expected)
 	}
 }
+
+func TestEvalRunPanic(t *testing.T) {
+	node, err := Parse("foo()")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = Run(node, map[string]interface{}{"foo": nil})
+	if err == nil {
+		err = fmt.Errorf("<nil>")
+	}
+
+	expected := "reflect: call of reflect.Value.Call on zero Value"
+	if err.Error() != expected {
+		t.Errorf("\ngot\n\t%+v\nexpected\n\t%v", err.Error(), expected)
+	}
+}

parser_test.go

@@ -179,3 +179,15 @@ func TestParseError(t *testing.T) {
 		}
 	}
 }
+
+func TestParseErrorPosition(t *testing.T) {
+	_, err := Parse("foo() + bar(**)")
+	if err == nil {
+		err = fmt.Errorf("<nil>")
+	}
+
+	expected := "unexpected token operator(**)\nfoo() + bar(**)\n------------^"
+	if err.Error() != expected {
+		t.Errorf("\ngot\n\t%+v\nexpected\n\t%v", err.Error(), expected)
+	}
+}