refactor: hashicorp tests

plugin/shared/call.go

@@ -23,9 +23,28 @@ func CallFunc(fn reflect.Value, args ...interface{}) (interface{}, error) {
 	for index, argument := range args {
 		if argument == nil {
 			argumentsValue[index] = reflect.Zero(fn.Type().In(index))
-		} else {
-			argumentsValue[index] = reflect.ValueOf(args[index])
+			continue
 		}
+
+		argumentValue := reflect.ValueOf(argument)
+		expectArgumentType := fn.Type().In(index)
+		actualArgumentType := reflect.TypeOf(argument)
+
+		// type match
+		if expectArgumentType == actualArgumentType {
+			argumentsValue[index] = argumentValue
+			continue
+		}
+
+		// type not match, check if convertible
+		if !actualArgumentType.ConvertibleTo(expectArgumentType) {
+			// function argument type not match and not convertible
+			err := fmt.Errorf("function argument %d's type is neither match nor convertible, expect %v, actual %v",
+				index, expectArgumentType, actualArgumentType)
+			return nil, err
+		}
+		// convert argument to expect type
+		argumentsValue[index] = argumentValue.Convert(expectArgumentType)
 	}
 
 	resultValues := fn.Call(argumentsValue)
@@ -40,8 +59,14 @@ func CallFunc(fn reflect.Value, args ...interface{}) (interface{}, error) {
 			return resultValues[0].Interface(), nil
 		}
 	} else if len(resultValues) == 1 {
-		// return one arguments: interface{}
-		return resultValues[0].Interface(), nil
+		// return one argument
+		if err, ok := resultValues[0].Interface().(error); ok {
+			// return error
+			return nil, err
+		} else {
+			// return interface{}
+			return resultValues[0].Interface(), nil
+		}
 	} else {
 		// return more than 2 arguments, unexpected
 		err := fmt.Errorf("function should return at most 2 arguments")

plugin/shared/call_test.go

@@ -0,0 +1,62 @@
+package shared
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCallFunc(t *testing.T) {
+	type data struct {
+		f      interface{}
+		args   []interface{}
+		expVal interface{}
+		expErr error
+	}
+	params := []data{
+		// zero argument, zero return
+		{f: func() {}, args: []interface{}{}, expVal: nil, expErr: nil},
+		// zero argument, return one value
+		{f: func() int { return 1 }, args: []interface{}{}, expVal: 1, expErr: nil},
+		{f: func() string { return "a" }, args: []interface{}{}, expVal: "a", expErr: nil},
+		{f: func() interface{} { return 1.23 }, args: []interface{}{}, expVal: 1.23, expErr: nil},
+		// zero argument, return error
+		{f: func() error { return errors.New("xxx") }, args: []interface{}{}, expVal: nil, expErr: errors.New("xxx")},
+		// zero argument, return one value and error
+		{f: func() (int, error) { return 1, errors.New("xxx") }, args: []interface{}{}, expVal: 1, expErr: errors.New("xxx")},
+		{f: func() (interface{}, error) { return 1.23, errors.New("xxx") }, args: []interface{}{}, expVal: 1.23, expErr: errors.New("xxx")},
+		// one argument, return one value
+		{f: func(n int) int { return n * n }, args: []interface{}{2}, expVal: 4},
+		{f: func(c string) string { return c + c }, args: []interface{}{"p"}, expVal: "pp"},
+		{f: func(arg interface{}) interface{} { return fmt.Sprintf("%v", arg) }, args: []interface{}{1.23}, expVal: "1.23"},
+		// two arguments in same type
+		{f: func(a, b int) int { return a * b }, args: []interface{}{2, 3}, expVal: 6},
+		// two arguments in different type
+		{
+			f: func(n int, c string) string {
+				var s string
+				for i := 0; i < n; i++ {
+					s += c
+				}
+				return s
+			},
+			args:   []interface{}{3, "p"},
+			expVal: "ppp",
+		},
+	}
+
+	for _, p := range params {
+		fn := reflect.ValueOf(p.f)
+		val, err := CallFunc(fn, p.args...)
+		if !assert.Equal(t, p.expErr, err) {
+			t.Fatal(err)
+		}
+		if !assert.Equal(t, p.expVal, val) {
+			t.Fatal()
+		}
+	}
+
+}