lexers.Analyse does not recognise Dockerfile, whereas quick.Highlight does

[paololazzari]

Given Dockerfile:

$ cat Dockerfile
FROM ubuntu
RUN echo hello world

then:

func main() {
	f, err := os.Open("Dockerfile")
	if err != nil {
		log.Panicf("failed reading file: %s", err)
	}
	defer f.Close()

	contents, err := ioutil.ReadAll(f)
	l := lexers.Analyse(string(contents))
	fmt.Println(l)
}

returns <nil> .

Whereas if I run:

func main() {
  fmt.Println(quick.Highlight(os.Stdout, "FROM ubuntu\nRUN echo hello world\n", "docker", "html", "monokai"))
}

this generates an html where the Dockerfile is indeed recognised

[alecthomas]

That is working as expected. With Analyse Chroma does best effort content analysis to detect the file type, while with quick you're explicitly specifying the file type.