Error handling and Unit testing in Golang

About this Project

This project is built using a Layered (clean) architecture, which emphasizes a clear separation of concerns between different layers of the application. Each layer in the architecture has its own responsibility, making the codebase more maintainable, scalable, and testable.

• Controllers handle incoming requests and process them by invoking the relevant services.
• Services contain business logic and interact with repositories for data access.
• Repositories abstract the data source and provide a clean interface for data operations, which makes the system flexible to switch between databases or external services.
• Models define the core domain entities of the application.

Setup

go mod tidy

then run go main to start the server

go run main.go

Install Gin

Fiber is an Express inspired web framework written in Go

go get -u github.com/gin-gonic/gin

Install Testify

Testify is a toolkit with common assertions and mocks that plays nicely with the standard library.

not use "github.com/go-playground/assert/v2" because it not compare deep equal

go get -u github.com/stretchr/testify/mock

Install Mockery

Mockery is a mock code autogenerator for Golang.

go get github.com/vektra/mockery/v2/.../

Go coverage highlighting (File should place beside of testing file)

Go coverage highlighting is a plugin for highlighting lines in the Go source code that are not covered by tests.

place in json settings file

"go.coverageOptions": "showBothCoveredAndUncoveredCode",
  "go.coverageDecorator": {
    "type": "highlight",
    "coveredHighlightColor": "rgba(59, 255, 125, 0.03)",
    "uncoveredHighlightColor": "rgba(255, 100, 81, 0.03)",
    "coveredBorderColor": "rgba(59, 255, 125, 0.03)",
    "uncoveredBorderColor": "rgba(255, 100, 81, 0.03)",
    "coveredGutterStyle": "blockgreen",
    "uncoveredGutterStyle": "blockred"
  },
  "editor.unicodeHighlight.nonBasicASCII": false,

Mockery

--dir: The directory in which to search for interfaces. (required)
--name: The name of the interface for which to generate a mock. (required)
--output: The directory to which the mock file will be written. (required)
--outpkg: The name of the package in which the mock should be generated. (required)
--filename: The name of the file to which the mock will be written. (optional)

NOTE (backslash) at the end of each line indicates that the command continues on the next line.

mock with a specified, clear path

• when to use: When you want to mock a function that is not in the same package.

services

mockery \
--dir=services/cacheService \
--name=ICacheService \
--output=services/mock \
--outpkg=mockService \
--filename=ICacheService.go

repositories

mockery \
--dir=repositories/privilegeRepository \
--name=IPrivilegeRepository \
--output=repositories/mock \
--outpkg=mockRepo \
--filename=IPrivilegeRepository.go

mock all interfaces in a package

services

mockery \
--dir=services \
--output=services/mock \
--outpkg=mockService \
--all

repositories

mockery \
--dir=repositories \
--output=repositories/mock \
--outpkg=mockRepo \
--all

How to run test

Unit Test

Unit tests are tests that test a single unit of code.

go test ./...

to see test coverage

go test -cover ./...

---

Error Handling in Go Application

This repository demonstrates a common approach to error handling in a Go application using the github.com/pkg/errors package. The application follows best practices for handling and logging errors, providing clear error messages and stack traces for debugging purposes.

Error Wrapping

The ce package provides functions for wrapping errors with additional context and handling specific error types. This allows for more informative error messages and consistent error handling across the application.

Error Types

The following error types are defined in the ce package:

• RedisError: Represents errors related to Redis operations.
• InvalidRequestError: Indicates an invalid request error, such as missing or malformed request parameters.
• InvalidFormatError: Denotes errors caused by invalid data formats.
• InternalError: Represents generic internal server errors.

Error Responses

The ce package also includes functions for generating and handling error responses. This ensures that error responses returned by the API are consistent and informative.

Generating Error Responses

The ErrorResponseJson function generates JSON error responses based on the error type. It maps each error type to an appropriate HTTP status code and error message.

Handling Error Responses

The HandleErrorResponse function is used to handle error responses in API handlers. It logs the error message and stack trace for debugging purposes.

Logging

The ce package includes functions for logging error messages and stack traces to aid in debugging.

Logging Error Stack Traces

The LogErrorStackTrace function logs the stack trace of an error, if available.

Logging Cause Error Messages

The LogCauseErrorMessages function logs the error message and its causes.

Logging Error Stack Traces and Endpoints

The GetErrorStackTraceAndEndpoint function logs the stack trace of an error along with the endpoint and HTTP method where the error occurred.

Usage

To use the error handling functionality in your application:

1. Import the ce package.
2. Wrap errors using the appropriate error type functions provided by the ce package.
3. Handle error responses in API handlers using the HandleErrorResponse function.