87 lines
1.8 KiB
Markdown
87 lines
1.8 KiB
Markdown
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# errors.go
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This is inspired from Ben Johnson's blog post [Failure is Your Domain](https://middlemost.com/failure-is-your-domain/)
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## The Error struct
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```go
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type Error struct {
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Code string
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Msg string
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Op string
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Err error
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}
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```
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* Code is the machine readable code, for reference purpose. All the codes should be a constant string. For example. `const ENotFound = "source not found"`.
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* Msg is the human readable message for end user. For example, `Your credit card is declined.`
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* Op is the logical Operator, should be a constant defined inside the function. For example: "bolt.UserCreate".
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* Err is the embed error. You may embed either a third party error or and platform.Error.
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## Use Case Example
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We inplement the following interface
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```go
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type OrganizationService interface {
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FindOrganizationByID(ctx context.Context, id ID) (*Organization, error)
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}
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func (c *Client)FindOrganizationByID(ctx context.Context, id platform.ID) (*platform.Organization, error) {
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var o *platform.Organization
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const op = "bolt.FindOrganizationByID"
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err := c.db.View(func(tx *bolt.Tx) error {
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org, err := c.findOrganizationByID(ctx, tx, id)
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if err != nil {
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return err
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}
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o = org
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return nil
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})
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if err != nil {
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return nil, &platform.Error{
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Code: platform.ENotFound,
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Op: op,
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Err: err,
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}
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}
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return o, nil
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}
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```
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To check the error code
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```go
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if platform.ErrorCode(err) == platform.ENotFound {
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...
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}
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```
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To serialize the error
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```go
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b, err := json.Marshal(err)
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```
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To deserialize the error
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```go
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e := new(platform.Error)
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err := json.Unmarshal(b, e)
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```
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