huge refactoring

internal/pkg/xerror/xerror_test.go

@@ -0,0 +1,97 @@
+package xerror
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+/*
+Error 1.0: op = "foo"
+Error 1.1: op = "bar"
+Error 1.2: code = "invalid", op = "baz", message = "nested error"
+Error 1.3: message = "root error"
+*/
+func scenario1() error {
+	rootErr := errors.New("root error")
+	nestedErr := Invalid("baz", "nested error", rootErr)
+	wrappingErr := New("bar", nestedErr)
+	return New("foo", wrappingErr)
+}
+
+/*
+Error 2.0: op = "foo"
+Error 2.1: op = "bar"
+Error 2.2: code = "timeout", op = "bar", message = "nested error"
+*/
+func scenario2() error {
+	nestedErr := Timeout("bar", "nested error", nil)
+	wrappingErr := New("bar", nestedErr)
+	return New("foo", wrappingErr)
+}
+
+// Error 3.0: code = "", op = "foo"
+func scenario3() error {
+	return New("foo", nil)
+}
+
+func TestError(t *testing.T) {
+	// should return the Error 1.3
+	// message.
+	err := scenario1()
+	assert.Equal(t, "root error", err.Error())
+	// should return the Error 2.2 message with
+	// its code.
+	err = scenario2()
+	assert.Equal(t, "<timeout> nested error", err.Error())
+}
+
+func TestCode(t *testing.T) {
+	// should be an empty code if no error.
+	assert.Equal(t, "", fmt.Sprintf("%s", Code(nil)))
+	// should be the code of Error 1.2.
+	err := scenario1()
+	assert.Equal(t, InvalidCode, Code(err))
+	// should be the code of Error 2.2.
+	err = scenario2()
+	assert.Equal(t, TimeoutCode, Code(err))
+	// should be the default code.
+	err = scenario3()
+	assert.Equal(t, InternalCode, Code(err))
+	err = errors.New("some error")
+	assert.Equal(t, InternalCode, Code(err))
+}
+
+func TestMessage(t *testing.T) {
+	// should be an empty message if no error.
+	assert.Equal(t, "", Message(nil))
+	// should be the message of Error 1.2.
+	err := scenario1()
+	assert.Equal(t, "nested error", Message(err))
+	// should be the default message.
+	err = errors.New("some error")
+	assert.Equal(t, defaultMessage, Message(err))
+}
+
+func TestOp(t *testing.T) {
+	// should be an empty op if no error.
+	assert.Equal(t, "", Op(nil))
+	// should be the chain of op in this order:
+	// Error 1.0 -> Error 1.1 -> Error 1.2.
+	err := scenario1()
+	assert.Equal(t, "foo: bar: baz", Op(err))
+	/*
+		should be the chain of op in this order:
+		Error 2.0 -> Error 2.1.
+
+		As Error 2.1 and Error 2.2 shares the same
+		op, Error 2.2 op is not displayed.
+	*/
+	err = scenario2()
+	assert.Equal(t, "foo: bar", Op(err))
+	// should be an empty op if not Error.
+	err = errors.New("some error")
+	assert.Equal(t, "", Op(err))
+}