Code created while working through "100 Go mistakes and how to avoid them" by Teiva Harsanyi.
feat: add no45
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no45/main.go
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no45/main.go
···
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package main
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import (
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"errors"
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"fmt"
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"log"
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)
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type ErrNotEven struct {
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err error
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}
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func (ene *ErrNotEven) Add(err error) {
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ene.err = errors.Join(ene.err, err)
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}
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func (ene *ErrNotEven) Error() string {
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return ene.err.Error()
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}
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func assertEven(num *int) error {
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var err *ErrNotEven
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if num == nil {
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err = &ErrNotEven{}
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err.Add(errors.New("argument can not be null"))
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}
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if (*num % 2) != 0 {
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if err == nil {
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err = &ErrNotEven{}
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}
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err.Add(fmt.Errorf("number '%d' is not even", *num))
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}
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return err
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}
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func main() {
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num := 2
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if err := assertEven(&num); err != nil {
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log.Fatalln(err)
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}
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}