package chroma

import (
	"testing"

	"github.com/alecthomas/assert"
	"github.com/stretchr/testify/require"
)

func TestNewlineAtEndOfFile(t *testing.T) {
	l := Coalesce(MustNewLexer(&Config{EnsureNL: true}, Rules{
		"root": {
			{`(\w+)(\n)`, ByGroups(Keyword, Whitespace), nil},
		},
	}))
	it, err := l.Tokenise(nil, `hello`)
	assert.NoError(t, err)
	assert.Equal(t, []Token{{Keyword, "hello"}, {Whitespace, "\n"}}, it.Tokens())

	l = Coalesce(MustNewLexer(nil, Rules{
		"root": {
			{`(\w+)(\n)`, ByGroups(Keyword, Whitespace), nil},
		},
	}))
	it, err = l.Tokenise(nil, `hello`)
	assert.NoError(t, err)
	assert.Equal(t, []Token{{Error, "hello"}}, it.Tokens())
}

func TestMatchingAtStart(t *testing.T) {
	l := Coalesce(MustNewLexer(&Config{}, Rules{
		"root": {
			{`\s+`, Whitespace, nil},
			{`^-`, Punctuation, Push("directive")},
			{`->`, Operator, nil},
		},
		"directive": {
			{"module", NameEntity, Pop(1)},
		},
	}))
	it, err := l.Tokenise(nil, `-module ->`)
	assert.NoError(t, err)
	require.Equal(t,
		[]Token{{Punctuation, "-"}, {NameEntity, "module"}, {Whitespace, " "}, {Operator, "->"}},
		it.Tokens())
}