tests/testthat/test-syuzhet.R

In syuzhet: Extracts Sentiment and Sentiment-Derived Plot Arcs from Text

context("Getting text from files")

file  <- system.file("extdata", "portrait.txt", package = "syuzhet")
joyce <- get_text_as_string(file)

test_that("Text files can be read locally and parsed correctly",{
  expect_that(joyce, is_a("String"))
  expect_that(length(joyce), equals(1))
})

context("Parsing sentences")

sents <- get_sentences(joyce)

test_that("Sentences are correctly parsed.", {
  expect_that(sents, is_a("character"))
  expect_true(length(sents) > 1 ) # i.e., it's not just a single string anymore
  expect_equal(sents[2], "He was baby tuckoo.")
})

context("Getting sentiment")

syu   <- get_sentiment(sents, method = "syuzhet")
bing  <- get_sentiment(sents, method = "bing")
afinn <- get_sentiment(sents, method = "afinn")
nrc   <- get_sentiment(sents, method = "nrc")

test_that("Sentiments are returned correctly", {
  expect_that(syu, is_a("numeric"))
  expect_that(bing, is_a("integer"))
  expect_that(afinn, is_a("integer"))
  expect_that(nrc, is_a("numeric")) # because it is averages
  expect_equal(length(sents), length(syu))
  expect_equal(length(sents), length(bing))
  expect_equal(length(sents), length(afinn))
  expect_equal(length(sents), length(nrc))
})

context("Getting Sentiment in Parallel")
cl <- parallel::makeCluster(2) # No more than 2 cores on CRAN
parallel::clusterExport(cl = cl, c("get_sentiment", "get_sent_values", "get_nrc_sentiment", "get_nrc_values"))

syu_par   <- get_sentiment(sents, method = "syuzhet", cl=cl)
bing_par  <- get_sentiment(sents, method = "bing", cl=cl)
afinn_par <- get_sentiment(sents, method = "afinn", cl=cl)
nrc_par   <- get_sentiment(sents, method = "nrc", cl=cl)

parallel::stopCluster(cl)

test_that("Parallel sentiments are returned correctly", {
  expect_that(syu_par, is_a("numeric"))
  expect_that(bing_par, is_a("integer"))
  expect_that(afinn_par, is_a("integer"))
  expect_that(nrc_par, is_a("numeric")) # because it is averages
  expect_equal(length(sents), length(syu_par))
  expect_equal(length(sents), length(bing_par))
  expect_equal(length(sents), length(afinn_par))
  expect_equal(length(sents), length(nrc_par))
  expect_equal(syu, syu_par)
  expect_equal(bing, bing_par)
  expect_equal(afinn, afinn_par)
  expect_equal(nrc, nrc_par)
})