https://github.com/kpeu3i/fielder
A Go tool to auto generate ENUM for struct fields
https://github.com/kpeu3i/fielder
code-generation enum golang orm-library
Last synced: 6 months ago
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A Go tool to auto generate ENUM for struct fields
- Host: GitHub
- URL: https://github.com/kpeu3i/fielder
- Owner: kpeu3i
- License: mit
- Created: 2022-07-31T12:50:46.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2025-04-25T16:15:16.000Z (about 1 year ago)
- Last Synced: 2025-04-25T17:34:32.093Z (about 1 year ago)
- Topics: code-generation, enum, golang, orm-library
- Language: Go
- Homepage:
- Size: 38.1 KB
- Stars: 8
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
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README
# Fielder
*Fielder* is a tool that generates Go code. It extracts fields from a struct and transforms them into ENUM.
Also, it adds useful types, methods and functions.
## Motivation
When using ORM-s like `gorm`, `go-pg`, `bun` you have to pass column names as arguments to different methods.
It is a pain to use raw strings for that, and it also might be a security risk.
It is better to rely on ENUM which represents columns for a specific table.
Also, the generated field names can be used in combination with Golang reflection (`FieldByName`) for different purposes.
## Features
The library provides the following features:
* Struct fields represented in an ENUM.
* Different functions and methods to work with the ENUM (validation, listing, conversion to string, etc).
* Tag-based field names extraction (regex can be used to extract a value from a tag).
* Embedded fields extraction.
* Field exclusion.
* Different formatting (camel, pascal, snake).
* Template overriding.
## Installation
go install github.com/kpeu3i/fielder@v1.6.0
## Usage
Put the `go:generate` directive in the same package as the struct you want to generate.
For example:
```go
//go:generate fielder -type=UserAccount
package models
type UserAccount struct {
FirstName string
LastName string
Email string
Password string
}
```
Then, run command bellow to generate the code:
$ go generate ./...
The following formatting strategies can be applied to the extracted field names (see `format` and `tag_format` flag):
* `snake_case` (e.g `first_name`)
* `camel_case` (e.g `firstName`)
* `pascal_case` (e.g `FirstName`)
For more details, check the [examples](examples) folder in the project root.
The following CLI flags are allowed:
```
Usage of fielder:
-embedded
Extract embedded fields (default false)
-excluded string
Comma separated list of excluded fields (default "")
-format string
Format of the generated type values extracted from the struct field (default "as_is")
-output string
Set output filename (default "/_fielder.go")
-pkg string
Package name to extract type from (default ".")
-suffix string
Suffix for the generated struct (default "Field")
-tag string
Tag to extract field values from (default "")
-tag_format string
Format of the generated type values extracted from the tag (default "as_is")
-tag_regexp string
Regular expression to parse field value from a tag (default "")
-tag_strict
Strict mode for tag parsing (returns error if tag is not found)
-tpl string
Set template filename (default "")
-type string
Type to extract fields from
```
## Generated types, functions and methods
When *Fielder* is applied to a type, it will generate public functions/methods and types:
* Type `` represents fields ENUM:
* Method `::IsValid` returns true if the value is a valid ENUM.
* Method `::String` returns the string representation of the value.
* Type `List` represents collection of ENUM fields:
* Method `List::Len` returns the number of values in the collection.
* Method `List::IsEmpty` returns true if the collection is empty.
* Method `List::Contains` returns true if the collection contains the value.
* Method `List::Equals` returns true if the two collections are equal.
* Method `List::Similar` returns true if the two collections contain the same values.
* Method `List::Add` adds the values to the collection.
* Method `List::AddIfNotContains` adds the values to the collection if they are not already present.
* Method `List::Remove` removes the values from the collection.
* Method `List::Clear` clears the collection.
* Method `List::Clone` returns a pointer to a copy of the collection.
* Method `List::Strings` returns a slice with all the strings of the collection items.
* Functions:
* `Values` returns a slice with all the values of the ENUM.
* `Strings` returns a slice with all the strings of the ENUM.
* `New` returns a new collection with all the values of the ENUM.
* `NewWith` returns a new collection with the given values of the ENUM.
## Inspiring projects
* [enumer](https://github.com/dmarkham/enumer)
* [stringer](https://pkg.go.dev/golang.org/x/tools/cmd/stringer)