cheat/internal/frontmatter/frontmatter.go
Chris Lane 5288bd0c1c fix(frontmatter): resolve issue #544
- Fix error in `frontmatter.Parse` which would cause a `panic` when
  encountering malformed frontmatter

- Add a unit-test to cover the above
2020-03-11 18:54:46 -04:00

44 lines
1.1 KiB
Go

package frontmatter
import (
"fmt"
"strings"
"gopkg.in/yaml.v1"
)
// Frontmatter encapsulates cheatsheet frontmatter data
type Frontmatter struct {
Tags []string
Syntax string
}
// Parse parses cheatsheet frontmatter
func Parse(markdown string) (string, Frontmatter, error) {
// specify the frontmatter delimiter
delim := "---"
// initialize a frontmatter struct
var fm Frontmatter
// if the markdown does not contain frontmatter, pass it through unmodified
if !strings.HasPrefix(markdown, delim) {
return strings.TrimSpace(markdown), fm, nil
}
// otherwise, split the frontmatter and cheatsheet text
parts := strings.SplitN(markdown, delim, 3)
// return an error if the frontmatter parses into the wrong number of parts
if len(parts) != 3 {
return markdown, fm, fmt.Errorf("failed to delimit frontmatter")
}
// return an error if the YAML cannot be unmarshalled
if err := yaml.Unmarshal([]byte(parts[1]), &fm); err != nil {
return markdown, fm, fmt.Errorf("failed to unmarshal frontmatter: %v", err)
}
return strings.TrimSpace(parts[2]), fm, nil
}