package lexer
import (
  "testing"
  "monkey/token"
)

func TestNextToken(t *testing.T) { 
  input := `=+(){},;`
  
  tests := []struct{
    expectedType token.TokenType
    expectedLiteral string
  }{
    {token.ASSIGN, "="},
    {token.PLUS, "+"},
    {token.LPAREN, "("},
    {token.RPAREN, ")"},
    {token.LBRACE, "{"},
    {token.RBRACE, "}"},
    {token.COMMA, ","},
    {token.SEMICOLON, ";"},
    {token.EOF, ""},
  }

  l := New(input)
  for i, tt := range tests {
    tok := l.NextToken()

    if tok.Type != tt.expectedType {
      t.Fatalf("tests[%d] - tokentype wrong. expected=%q, got %q",
        i, tt.expectedType, tok.Type)
    }
    if tok.Literal != tt.expectedLiteral {
      t.Fatalf("tests[%d] - literal wrong. expected=%q, got %q",
        i, tt.expectedLiteral, tok.Literal)
    }
  }
}