Parse yaml error for map - go

Question

I've the following program in which I need to parse yaml
with the following structure
https://codebeautify.org/yaml-validator/cbabd352
this is valid yaml and I use byte to make it more simple
maybe the indentation was changed during the copy paste to the question but you can see in the link that the yaml is valid
The yaml have an api_version
and runners, for each runner (key which is name) I've a list of commands
and I need to print those commands for function1 and function4 ,what am I doing wrong here ?
package main
import (
"fmt"
"log"
"gopkg.in/yaml.v2"
)
var runContent = []byte(`
api_ver: 1
runners:
- name: function1
type:
- command: spawn child process
- command: build
- command: gulp
- name: function2
type:
- command: run function 1
- name: function3
type:
- command: ruby build
- name: function4
type:
- command: go build
`)
type Result struct {
Version string `yaml:"api_ver"`
Runners []Runners `yaml:"runners"`
}
type Runners struct {
Name string `yaml:"name"`
Type []Command `yaml:"type"`
}
type Command struct {
Command string `yaml:"command"`
}
func main() {
var runners []Result
err := yaml.Unmarshal(runContent, &runners)
if err != nil {
log.Fatalf("Error : %v", err)
}
fmt.Printf("%+v", runners[0])
}
The error which I got cannot unmarshal !!map into []main.Result
I cannot change the yaml and it should be exactly like this
https://codebeautify.org/yaml-validator/cbabd352
This is the code
https://play.golang.org/p/zidjOA6-gc7

Answer 1

The yaml that you have provided contains error in token. Validate the yaml used in your code here https://codebeautify.org/yaml-validator/cbaabb32
After that Create a variable of struct type result not an array. Because the yaml that you are using is creating a struct with Runners array and api_version.
This
var runners []Result
should be
var runners Result
Since because the struct is not a slice. To fetch the list of command for a name of function used in yaml. You need to loop over the runners array to find the name of function and get the value of commands for that function.
Below is the working code:
package main
import (
"fmt"
"log"
"gopkg.in/yaml.v2"
)
var runContent = []byte(`
api_ver: 1
runners:
- name: function1
type:
- command: spawn child process
- command: build
- command: gulp
- name: function2
type:
- command: run function 1
- name: function3
type:
- command: ruby build
- name: function4
type:
- command: go build
`)
type Result struct {
Version string `yaml:"api_ver"`
Runners []Runners `yaml:"runners"`
}
type Runners struct {
Name string `yaml:"name"`
Type []Command `yaml:"type"`
}
type Command struct {
Command string `yaml:"command"`
}
func main() {
var runners Result
// parse mta yaml
err := yaml.Unmarshal(runContent, &runners)
if err != nil {
log.Fatalf("Error : %v", err)
}
commandList := getCommandList("function1", runners.Runners)
fmt.Printf("%+v", commandList)
}
func getCommandList(name string, runners []Runners) []Command {
var commandList []Command
for _, value := range runners {
if value.Name == name {
commandList = value.Type
}
}
return commandList
}
Playground example