context("Simple tests")

test_that("Sym", {
  xs <- Sym('xs')
  texp <- Taylor(exp(xs), xs, 0, 3)
  
  expect_equal(as.character(xs), "xs")
  expect_equal(class(xs), c("Sym", "character"))
  
  expect_equal(class(texp), c("Sym", "character"))
  expect_equal(as.expression(texp), expression(xs + xs^2/2 + xs^3/6 + 1))
  expect_equal(as.character(as.expression(texp)), "xs + xs^2/2 + xs^3/6 + 1")
  expect_equal(as.character(texp), "xs + xs^2/2 + xs^3/6 + 1")
})

test_that("Expr", {
  x <- Sym("x")
  x3expr <- Expr(x*x*x)
  expect_equal(as.character(yacas(x3expr)), "x^3")
  expect_equal(Eval(x3expr, list(x = 2)), 8)
  #expect_equal(as.character(x3expr*x3expr), "x^6")
  #expect_equal(as.character(yacas(sin(x3expr))), "sin(x^3)")
})

test_that("TeXForm", {
  expect_equal(yacas("TeXForm(x*x)"), "x ^{2}")
  
  #FIXME: Fails Travis but not locally; why?
  #expect_equal(TeXForm(yacas("x*x")), "$x ^{2}$")
  
  expect_equal(yacas("TeXForm(x*x)", retclass = "unquote"), "x ^{2}")
  
  x <- Sym("x")
  expect_equal(TeXForm(x*x), "x ^{2}")
})

# test_that("Yacas mode", {
#   expect_equal("Enter Yacas commands here. Type quit to return to R", 
#                capture.output(
#                  testthat::with_mock(
#                    readline = function(x) { return("quit")}, 
#                    savehistory = function(x) { return() },
#                    loadhistory = function(x) { return() },
#                    
#                    yacmode())))
#   
#   ran_before <- FALSE
#   expect_equal(c("Enter Yacas commands here. Type quit to return to R", 
#                  "yacas_expression(x^3)"),
#                capture.output(
#                  testthat::with_mock(
#                    readline = function(x) {
#                      if (!ran_before) {
#                        ran_before <<- TRUE
#                        return("x*x*x")
#                      }
#                      return("quit")
#                     }, 
#                    savehistory = function(x) { return() },
#                    loadhistory = function(x) { return() },
#                    
#                    yacmode())))
# })

# 
# 
# test_that("Linalg", {
#   
#   m <- matrix(0, 4, 4)
#   diag(m) <- "r"
#   ms <- as.Sym(m)
#   
#   expect_equal(as.character(ms), "{ { r, 0, 0, 0 }, { 0, r, 0, 0 }, { 0, 0, r, 0 }, { 0, 0, 0, r } }")
#   expect_equal(EigenValues(ms)$LinAlgForm, rep("r", 4))
#   
#   
#   m <- matrix(c("2", "1", "1", "2"), 2, 2)
#   ms <- as.Sym(m)
#   
#   expect_equal(unlist(Eval(EigenValues(ms))), c(1, 3))
# })