Keys with underscores are not parsed correctly

[kernel-sanders]

This library does not parse keys with underscores correctly. The yaml.v3 library has no issue with them.

import (
    "log"
    "fmt"
    invopop "github.com/invopop/yaml"
    yamlv3 "gopkg.in/yaml.v3"
)

type Config struct {
    Normal             string `yaml:"normal"`
    OneUnderscore      string `yaml:"one_underscore"`
    TwoUnderscores     string `yaml:"two_under_scores"`
    OneUnderscoreInt   int    `yaml:"one_underscoreint"`
    TwoUnderscoresInt  int    `yaml:"two_under_scoresint"`
}

func main() {
    yamlData := `
---
normal: test
one_underscore: test1
two_under_scores: test2
one_underscoreint: 1
two_under_scoresint: 2
`
    var config Config
    err := invopop.Unmarshal([]byte(yamlData), &config)
    if err != nil {
        log.Fatalf("error: %v", err)
    }
    fmt.Printf("invopop - normal: %s\n", config.Normal)
    fmt.Printf("invopop - one_underscore: %s\n", config.OneUnderscore)
    fmt.Printf("invopop - two_under_scores: %s\n", config.TwoUnderscores)
    fmt.Printf("invopop - one_underscoreint: %d\n", config.OneUnderscoreInt)
    fmt.Printf("invopop - two_under_scoresint: %d\n", config.TwoUnderscoresInt)


    var config2 Config
    err = yamlv3.Unmarshal([]byte(yamlData), &config2)
    if err != nil {
        log.Fatalf("error: %v", err)
    }
    fmt.Printf("yamlv3 - normal: %s\n", config2.Normal)
    fmt.Printf("yamlv3 - one_underscore: %s\n", config2.OneUnderscore)
    fmt.Printf("yamlv3 - two_under_scores: %s\n", config2.TwoUnderscores)
    fmt.Printf("yamlv3 - one_underscoreint: %d\n", config2.OneUnderscoreInt)
    fmt.Printf("yamlv3 - two_under_scoresint: %d\n", config2.TwoUnderscoresInt)
}

Output:

invopop - normal: test
invopop - one_underscore:
invopop - two_under_scores:
invopop - one_underscoreint: 0
invopop - two_under_scoresint: 0
yamlv3 - normal: test
yamlv3 - one_underscore: test1
yamlv3 - two_under_scores: test2
yamlv3 - one_underscoreint: 1
yamlv3 - two_under_scoresint: 2

[mcblair]

Just ran into this myself. Turns out that invopop/yaml marshals to JSON first, which strips the YAML tags. Adding JSON tags fixes this — please let me know if this works for you @kernel-sanders.

This isn't ideal by any means.

[kernel-sanders]

Yes, and apparently this is intended behavior. The Go yaml repo most people seem to use is https://github.com/kubernetes-sigs/yaml which stated as much: kubernetes-sigs/yaml#102 (comment)