theodesp / go-invariant

A way to provide descriptive errors in development but generic errors in production for go programs.

go-invariant

A way to provide descriptive errors in development but generic errors in production.

Install

go get github.com/theodesp/go-invariant

Usage

It's intended for projects which require a simple invariant check and display of error messages depending on the current env variables

Examples:

// main.go
package main

import (
	"github.com/theodesp/go-invariant"
	"fmt"
)

func main() {
	res:= invariant.Invariant(1!=1,"")
	fmt.Println(res)
}

and run on the command line

$ go run main.go
    invariant requires an error message argument

$ go run main.go -env production
    invariant exception in production environment. Please use development flag to see the full error message

// main.go
package main

import (
	"github.com/theodesp/go-invariant"
	"fmt"
)

func main() {
	res:= invariant.Invariant(1!=1,"You must say %s when talking to Dragons", "your majesty")
	fmt.Println(res)
}

and run on the command line

$ go run main.go
    You must say your majesty when talking to Dragons

$ go run main.go -env production
    invariant exception in production environment. Please use development flag to see the full error message

Note: When env environment variable or command line switch is not production, the message is required. If omitted, invariant will throw regardless of the truthness of the condition. When env is production, the message will be a generic one so it can be stripped away By default env is assumed to be development.