February 19, 2020

Mocking in Go Part 2

In a previous post, I talked about Gomock. I want to spend a bit more time on it. As I’ve mentioned, setting up Gomock requires Download mockgen go get github.com/golang/mock/mockgen@latest Edit your go.mod module jcheng.org go 1.13 require ( github.com/golang/mock v1.4.0 ) Add the go:generate incantation to your code //go:generate mockgen -source $GOFILE -destination mock_$GOFILE -package $GOPACKAGE package pastself import ( "time" ) ... Use mocks in your test case.

February 19, 2020

Few Annoying Things about Go

As promised, a few thoughts about Go that is annoying. No Generics Code generation is tightly coupled with the tool chain. When I need to use code generation, i.e., enums and mocks, the use case can be solved with generics instead. No lambda syntax Scala has a lambda syntax to make it easy to work with anonymous function objects val numbers = Seq(1, 5, 2, 100) val doubled = numbers.map( n => n * 2 ) Java has a similar syntax

February 14, 2020

Mocking in Go

Today I want to talk a little about the testify and gomock packages and doing mocks in Go. Mocking is essential when writing code that depends on external services, e.g., microservices, message brokers, and datastores. For many people, this means web applications: My system has business rules and talks to multiple services. How do I test the business rules without setting up all the services locally? Some people argue that mocks create a false sense of test coverage and introduce blind spots.

February 8, 2020

Why I like Go

I have a few side projects, published and unpublished. By trade, I’ve come to programming as a Java programmer. I started coding directly against the Servlet API and have coded using Enterprise Java Beans, Play Framework, Spring Framework, and even some Scala. Lately, I’ve been coding mainly in Go with some Python. Go is a really nice programming language. Some people like it for its simplicity. I want to offer a different take on why you should learn and use Go for your own projects.

February 7, 2020

Delegation

One thing about job hopping is that you get to experience new perspectives on how people work. It forces you to reconsider what’s obvious. Take delegation for example. I used to think anyone with a bit of experience can do it effectively. It’s just about decomposing a system and assigning components to different people, right? It turns out effective delegation is much more nuanced. Situational Leadership Situation Leadership is a model that ascribes different delegation styles based on the competency (skill) and commitment (motivation) of each team member.

January 4, 2020

Viper Examples

Viper is a configuration library fo Go. It has been my go to library for configs. Some of the best features of Viper are: Ability to unmarshal subsets of a configuration file into a Go struct Ability to override contents of a configuration file using OS environment variables Here’s a brief example that demonstrates both features: Assume you have a configuration file at $HOME/server.toml resolve_dns = true http_keep_alive = 5 [example_com] doc_root = "/var/www/example_com" allow_files = "*.

November 29, 2019

Go1 13 Errors

For me, Go 1.13 arrived with anticipation of better error handling. Presently, the second Google search result for Go 1.13 error hanlding is an article that refers to the “xerrors” package. One feature of the xerrors package is that it produced errors with a stack trace showing where the error came from. The addition to Go 1.13, however, did not include this particular feature, and left me spending frustrating hours trying to debug the loss of stack trace after switching from xerrors to the standard library.

September 3, 2019

Why We Code Review

Code review can be an important part of a team’s culture, so it is worth thinking about. If you asked me about code review two years ago, I would’ve said its key to maintaining code quality and mentoring less experienced programmers. Now I know better. Code review is much about making the code better as it is about making the team happier. How the team runs code reviews should be based on the team’s values and culture.

August 22, 2019

Interview Questions

Good technical interview questions are hard to find. In the last month, I’ve seen some really great ones and equally bad ones. I want to go through some of them and write down my highly biased 5-star rating on their effectiveness. First, for some context on how I evaluate interview questions. Your interview questions should be: Respectful of the candidates Objective and evaluated consistently Gathers relevant and insightful data

August 19, 2019

Own Your Data

I previously wrote about owning my own data. An important part of data ownership is backing up your data. I use S3 as my long term data store. It is pretty easy to set this up using Terraform.

S3

Provisioning a S3 bucket is simply a single Terraform resource:

resource "aws_s3_bucket" "repo_archive_log" {
  acl = "log-delivery-write"
  bucket = "example-bucket"
  tags = {
    Name = "example"
    TTL = "persistent"
    ManagedBy = "Terraform"
  }
}