cannot unmarshal !!seq into string in Go

Question

I am getting the following error while using sequence of array in yaml file. I am not sure what fix required to be applied as I am new to 'Go' and learning the program.

2021/07/28 14:16:07 yaml: unmarshal errors:
  line 3: cannot unmarshal !!seq into string

Yaml:

ENV:
  attributes:
    - foo
    - boo
    - coo

code:

package test

import (
    "fmt"
    "gopkg.in/yaml.v3"
    "io/ioutil"
    "log"
    "testing"
)

type ENV struct {
    Attributes string `yaml:"attributes"`
}


func TestTerraformAzureCosmosDBExample(t *testing.T) {


    yFile, err := ioutil.ReadFile("config.yaml")


    if err != nil {
        log.Fatal(err)
    }

    data := make(map[string]ENV)

    err = yaml.Unmarshal(yFile, &data)
    if err != nil {
        log.Fatal(err)
    }
    for k, v := range data {
        fmt.Printf(`key: %v, value: %v`, k,v)
    }

}

Expected:

foo boo coo

Actual:

C:\Pfoo\boo>go test -v
=== RUN   TestTerraformAzureCosmosDBExample
2021/07/28 14:16:07 yaml: unmarshal errors:
  line 3: cannot unmarshal !!seq into string
exit status 1
FAIL    foo_test   0.199s

Answer 1

As mkopriva, said in the comments, you should change to []string, so the struct would be

type ENV struct {
    Attributes []string `yaml:"attributes"`
}

And why is that ? the yaml, reconizes the ENV: attributes: - foo - boo - coo as a array. What you can do to turn into one string, is use: strings.Join(String Slice,{ something to separate, you can let this as "")`

the imports are : "strings", and strings.Join returns a string.

Answer 2

As per suggestion of mkopriva changing Attributes field to string[] instead of string:

package test

import (
    "fmt"
    "gopkg.in/yaml.v3"
    "io/ioutil"
    "log"
    "testing"
)

type ENV struct {
    Attributes []string `yaml:"attributes"`
}

func TestTerraformAzureCosmosDBExample(t *testing.T) {

    yFile, err := ioutil.ReadFile("config.yaml")

    if err != nil {
        log.Fatal(err)
    }

    data := make(map[string]ENV)

    err = yaml.Unmarshal(yFile, &data)
    if err != nil {
        log.Fatal(err)
    }
    for k, v := range data {
        fmt.Printf(`key: %v, value: %v`, k, v)
    }

}