# How to fix the "tag is not aligned, should be: (...) (tagalign)"

# Golang Tag Alignment

Tag Alignment is way more easier subject than the [Field Alignment and structure size optimization](https://blog.skopow.ski/how-to-fix-the-fieldalignment-struct-with-32-pointer-bytes-could-be-24-govet) that I've covered in the previous post.

You can use tags for additional functionalities on the `struct`'s fields, commonly used by the encoders.

> \[1\] Go offers [struct tags](https://go.dev/ref/spec#Tag) [which are](https://go.dev/ref/spec#Tag) discoverable via reflection. These enjoy a wide range of use in the standard library in the JSON/XML and other encoding packages.

Tagged `struct` can look as follows:

```go
// Tags not aligned and not sorted.
type Address struct {
	Name    string `yaml:"name" json:"name" xml:"name"`
	Street  string `yaml:"street" json:"street" xml:"street"`
	ZipCode string `yaml:"zipCode" json:"zipCode" xml:"zipCode"`
	City    string `yaml:"city" json:"city" xml:"city"`
}
```

Such a `struct` is totally valid and compiles successfully, however tags (`yaml`, `json` and `xml`) are not sorted and not aligned, thus it might be harder to read.

What's the `golangci-lint` outcome on that file?

# Problem

When running a linter you can see errors that might look like these:

```bash
golangci-lint run ./...
tags.go:4:17: tag is not aligned, should be: json:"name"    xml:"name"    yaml:"name" (tagalign)
	Name    string `yaml:"name" json:"name" xml:"name"`
	               ^
tags.go:5:17: tag is not aligned, should be: json:"street"  xml:"street"  yaml:"street" (tagalign)
	Street  string `yaml:"street" json:"street" xml:"street"`
	               ^
tags.go:6:17: tag is not aligned, should be: json:"zipCode" xml:"zipCode" yaml:"zipCode" (tagalign)
	ZipCode string `yaml:"zipCode" json:"zipCode" xml:"zipCode"`
	               ^
tags.go:7:17: tag is not aligned, should be: json:"city"    xml:"city"    yaml:"city" (tagalign)
	City    string `yaml:"city" json:"city" xml:"city"`
```

`tagalign` command that is being used by the `golangci-lint` to detect these issues reports where the error is and how it should looks like when fixed (that's a way more better output than from the [`govet`](https://blog.skopow.ski/how-to-fix-the-fieldalignment-struct-with-32-pointer-bytes-could-be-24-govet#heading-problem)).

# Solution

The solution comes also from the `tagalign` package:

> \[2\] TagAlign is used to align and sort tags in Go struct. It can make the struct more readable and easier to maintain.

We can fix this in two ways:

1. Using the `--fix` param for the `golangci-lint` command (since the version `v1.53`):
    
    ```bash
    golangci-lint run --fix ./...
    ```
    
2. Using `tagalign` in the standalone mode.
    
    ```bash
    // Install tagalign.
    go install github.com/4meepo/tagalign/cmd/tagalign@latest
    
    // Align tags.
    tagalign -fix ./...
    
    // Align and sort tags.
    tagalign -fix -sort ./...
    ```
    

More details on additional params for `tagalign` you can find directly on the [tagalign GH page](https://github.com/4meepo/tagalign).

How to configure `tagalign` with the `golangci-lint` please check the [latter documentation](https://golangci-lint.run/usage/linters/#tagalign).

Our sorted `Address` `struct` now looks as follows:

```go
// Tags aligned and sorted.
type Address struct {
	Name    string `json:"name"    xml:"name"    yaml:"name"`
	Street  string `json:"street"  xml:"street"  yaml:"street"`
	ZipCode string `json:"zipCode" xml:"zipCode" yaml:"zipCode"`
	City    string `json:"city"    xml:"city"    yaml:"city"`
}
```

# Sources

## Docs:

* [https://go.dev/wiki/Well-known-struct-tags](https://go.dev/wiki/Well-known-struct-tags)
    
* [https://go.dev/ref/spec#Tag](https://go.dev/ref/spec#Tag)
    
* [https://github.com/4meepo/tagalign](https://github.com/4meepo/tagalign)
    
* [https://golangci-lint.run/usage/linters/#tagalign](https://golangci-lint.run/usage/linters/#tagalign)
    

## Quotations:

* \[1\] - [https://go.dev/wiki/Well-known-struct-tags](https://go.dev/wiki/Well-known-struct-tags)
    
* \[2\] - [https://github.com/4meepo/tagalign?tab=readme-ov-file#go-tag-align](https://github.com/4meepo/tagalign?tab=readme-ov-file#go-tag-align)