forked from markphelps/optional
/
example_test.go
122 lines (102 loc) · 1.73 KB
/
example_test.go
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package optional_test
import (
"encoding/json"
"fmt"
"github.com/markphelps/optional"
)
func Example_get() {
values := []optional.String{
optional.NewString("foo"),
optional.NewString(""),
optional.NewString("bar"),
{},
}
for _, v := range values {
if v.Present() {
value, err := v.Get()
if err == nil {
fmt.Println(value)
}
}
}
// Output:
// foo
//
// bar
}
func Example_orElse() {
values := []optional.String{
optional.NewString("foo"),
optional.NewString(""),
optional.NewString("bar"),
{},
}
for _, v := range values {
fmt.Println(v.OrElse("not present"))
}
// Output:
// foo
//
// bar
// not present
}
func Example_if() {
values := []optional.String{
optional.NewString("foo"),
optional.NewString(""),
optional.NewString("bar"),
{},
}
for _, v := range values {
v.If(func(s string) {
fmt.Println("present")
})
}
// Output:
// present
// present
// present
}
func Example_marshalJSON() {
type example struct {
Field *optional.String `json:"field,omitempty"`
}
var values = []optional.String{
optional.NewString("foo"),
optional.NewString(""),
optional.NewString("bar"),
}
for _, v := range values {
out, _ := json.Marshal(&example{
Field: &v,
})
fmt.Println(string(out))
}
// Output:
// {"field":"foo"}
// {"field":""}
// {"field":"bar"}
}
func Example_unmarshalJSON() {
var values = []string{
`{"field":"foo"}`,
`{"field":""}`,
`{"field":"bar"}`,
"{}",
}
for _, v := range values {
var o = &struct {
Field optional.String `json:"field,omitempty"`
}{}
if err := json.Unmarshal([]byte(v), o); err != nil {
fmt.Println(err)
}
o.Field.If(func(s string) {
fmt.Println(s)
})
}
// Output:
// foo
//
// bar
}