One of the guarding principles of writing unit test is that there should be no real external calls for dependant services. Unit test should run by its own and can run without issues on any environment including local, build, test environment. This indicates there should be some mock responses whenever an external call is needed so that different unit test scenarios can be covered.How can this be done in GoLang? In GoLang, anything can be assigned to a variable even including functions. A variable can be created to reference a function and it can be called just like a normal function when neede...

In case there is below error encountered while running some go program:combining dwarf failed: unknown load command 0x80000034This may be due to that you are running go 1.16 on a Mac M! machine. If you go to check go version, it may tell you that you are running an arm version of go.go version go1.16.10 darwin/arm64In such cases, you can try below methods to workaround the issue.Try to upgrade the go version to 1.17 and run the code again. If this is not an option for you because you have to stick to go 1.16 for some reason, you may try to install an amd version of go 1.16. This should work pe...

Being indulged in Go for quite a while and having implemented web-related programs, grpc interfaces and Operators, I seem to be an advanced beginner now.However, I am still a raw hand in production-environmental debugging, which is cumbersome if done by querying logs or error messages. Imagine the scenario that a full-text search is called when the specific location of the error log is missing. Then what happens when those error logs are not only in one place? Yes, my error logs can no longer help me locate the errors quickly and accurately.Apparently, the lack of the try {…} catch...

Go is a language with the pointer type, by which we canPass pointer into a function and update value in-place.Add methods to a struct as (* T) A, which is different from (T) A().However, the pointer is type-safe in Go, meaning that there are such restrictions of the pointer.Different types of pointers are unconvertible.Pointer type cannot be used for calculation.Pointer types cannot be compared, either == nor !=.No mutual assignment between different pointer-type variables.For example, *int cannot be converted to *int32in the following code.func main() {...

There is some interview question may ask whether nil == nil be true in GoLang. Wil it be true. false or compilation error? To know the answer, some knowledge about nil in GoLang needs to be explained first.nil definitionAccording to Go's official documentation, the definition of nil is// nil is a predeclared identifier representing the zero value for a// pointer, channel, func, interface, map, or slice type.var nil Type // Type must be a pointer, channel, func, interface, map, or slice typenil is the zero value of types like pointer, channel, func, interface, map or slice. Itself is NOT a GoLa...

Sometime back we wrote a post explaining why there is no max/min function support for integers in GoLang, one of the reasons is that no overloading is supported and the function name has been used for other numeric types float64. To solve this problem and make max/min function support integer as well, either GoLang should support overloading like in Java or the same set of functions need to be created in a different package other than standard math. These don't look like good options as overloading is more a OOP concept and supporting the same set of functions in a different package doesn't so...

When generating RPC code using proto file template in GoLang, one may face the issue like below when running the command protoc.Error: exit status 1Output: --go_out: protoc-gen-go: plugins are not supported; use 'protoc --go-grpc_out=...' to generate gRPCSee https://grpc.io/docs/languages/go/quickstart/#regenerate-grpc-code for more information.Normally this issue is caused because the version of protoc-gen-go being used is not correct. One way to fix the issue is to follow the instructions provided by Google to run a new command.Another way to fix this is by having the Github version of proto...

Go is currently the most common programming language in cloud development. Though I use it very much in my work, I am still repeating certain mistakes. This article is more a record of these errors, figuring out the causes and solutions so that people who read this article will save themselves time when coming across the same problems.Let’s cut through to the tips.Don’t rely on index var in the for loopThe most common mistake we make is that we often create goroutine inside a for loop and rely on the index variable. For example,package mainimport ( "fmt" "sync")fun...