tests/testthat/test-join.r

In plyr: Tools for Splitting, Applying and Combining Data

context("Join")

# Create smaller subset of baseball data (for speed)
bsmall <- subset(baseball, id %in% sample(unique(baseball$id), 20))[, 1:5]
bsmall$id <- factor(bsmall$id)
bsmall <- bsmall[sample(rownames(bsmall)),  ]
rownames(bsmall) <- NULL

first <- ddply(bsmall, "id", summarise, first = min(year))

test_that("results consistent with merge", {
  b2 <- merge(bsmall, first, by = "id", all.x = TRUE)
  b3 <- join(bsmall, first, by = "id")
  b4 <- join(first, bsmall, by = "id")[names(b3)]

  b2 <- arrange(b2, id, year, stint)
  b3 <- arrange(b3, id, year, stint)
  b4 <- arrange(b4, id, year, stint)

  expect_that(b2, equals(b3))
  expect_that(b2, equals(b4))
})

test_that("order is preserved", {
  b3 <- join(bsmall, first, by = "id")

  expect_that(bsmall$id, equals(b3$id))
  expect_that(bsmall$year, equals(b3$year))
  expect_that(bsmall$stint, equals(b3$stint))
})

test_that("rownames are preserved", {
  b3 <- join(bsmall, first, by = "id")
  expect_that(rownames(b3), equals(rownames(bsmall)))
})

test_that("duplicated keys are duplicated", {
  x <- data.frame(a = c("a", "b"), b = c("a", "b"))
  y <- data.frame(a = c("a", "a"), z = c(1, 2))

  left <- join(x, y, by = "a")
  expect_that(nrow(left), equals(3))
  expect_that(left$z, equals(c(1, 2, NA)))

  inner <- join(x, y, by = "a", type = "inner")
  expect_that(nrow(inner), equals(2))
  expect_that(inner$z, equals(c(1, 2)))
})

test_that("full merge preserves x and y", {
  a <- data.frame(x = 1:10, a = 1:10)
  b <- data.frame(x = 11:15, b = 1:5)

  ab <- join(a, b, by = "x", type = "full")
  expect_that(names(ab), equals(c("x", "a", "b")))
  expect_that(ab$x, equals(1:15))
  expect_that(ab$a, equals(c(1:10, rep(NA, 5))))
  expect_that(ab$b, equals(c(rep(NA, 10), 1:5)))
})

test_that("left and right are equivalent", {
  d1 <- data.frame(a = 1:3, b = 1:3)
  d2 <- data.frame(a = 1:4, c = 1:4)

  right <- join(d1, d2, type="right", by = "a")
  left <- join(d2, d1, type="left", by = "a")
  expect_that(left[c("a", "b" ,"c")], equals(right[c("a", "b" ,"c")]))

  right <- join(d1, d2, type="right", by = "a", match = "first")
  left <- join(d2, d1, type="left", by = "a", match = "first")
  expect_that(left[c("a", "b" ,"c")], equals(right[c("a", "b" ,"c")]))

})


test_that("large number of columns work", {
  df1 <- data.frame(matrix(1:100, ncol = 50), y = 1:2)
  df2 <- data.frame(matrix(1:100, ncol = 50), z = 3:4)

  df <- join(df1, df2)
  expect_that(df$y, equals(1:2))
  expect_that(df$z, equals(3:4))

})

test_that("many potential combinations works", {
  factor_n <- function(m, n) {
    factor(sample(n, m, rep = T), levels = seq_len(n))
  }
  df1 <- as.data.frame(replicate(20, factor_n(100, 100)))
  df2 <- as.data.frame(replicate(20, factor_n(100, 100)))

  j <- join(df1, df2)
  j <- merge(df1, df2, all.x = TRUE)

})

test_that("joins with no common rows work", {
  a <- data.frame(a = 1:10)
  b <- data.frame(b = 1:10)

  full1 <- join(a, b, type = "full")
  full2 <- join(a, b, type = "full", match = "first")
  inner1 <- join(a, b, type = "inner")
  inner2 <- join(a, b, type = "inner", match = "first")
  left1 <- join(a, b, type = "left")
  left2 <- join(a, b, type = "left", match = "first")
  right1 <- join(a, b, type = "right")
  right2 <- join(a, b, type = "right", match = "first")

  expect_equal(nrow(full1), 20)
  expect_equal(nrow(full2), 20)
  expect_equal(nrow(inner1), 0)
  expect_equal(nrow(inner2), 0)
  expect_equal(nrow(left1), 10)
  expect_equal(nrow(left2), 10)
  expect_equal(nrow(right1), 10)
  expect_equal(nrow(right2), 10)
})

test_that("joins with zero row dataframe work", {
  a <- data.frame(a = integer())
  b <- data.frame(a = 1:10, b = letters[1:10])

  full1 <- join(a, b, type = "full")
  full2 <- join(a, b, type = "full", match = "first")
  inner1 <- join(a, b, type = "inner")
  inner2 <- join(a, b, type = "inner", match = "first")
  left1 <- join(a, b, type = "left")
  left2 <- join(a, b, type = "left", match = "first")
  right1 <- join(a, b, type = "right")
  right2 <- join(a, b, type = "right", match = "first")

  expect_equal(nrow(full1), 10)
  expect_equal(nrow(full2), 10)
  expect_equal(nrow(inner1), 0)
  expect_equal(nrow(inner2), 0)
  expect_equal(nrow(left1), 0)
  expect_equal(nrow(left2), 0)
  expect_equal(nrow(right1), 10)
  expect_equal(nrow(right2), 10)
})

test_that("column orders are common, x only, y only", {
  a <- data.frame(a = 1:3, b = 1:3)
  b <- data.frame(a = 1:4, c = 1:4)

  full1 <- join(a, b, type = "full")
  full2 <- join(a, b, type = "full", match = "first")
  inner1 <- join(a, b, type = "inner")
  inner2 <- join(a, b, type = "inner", match = "first")
  left1 <- join(a, b, type = "left")
  left2 <- join(a, b, type = "left", match = "first")
  right1 <- join(a, b, type = "right")
  right2 <- join(a, b, type = "right", match = "first")

  expect_equal(names(full1), c("a", "b", "c"))
  expect_equal(names(full2), c("a", "b", "c"))
  expect_equal(names(inner1), c("a", "b", "c"))
  expect_equal(names(inner2), c("a", "b", "c"))
  expect_equal(names(left1), c("a", "b", "c"))
  expect_equal(names(left2), c("a", "b", "c"))
  expect_equal(names(right1), c("a", "b", "c"))
  expect_equal(names(right2), c("a", "b", "c"))

})

test_that("strings match to factors", {

  dfF <- data.frame(character = c("Aeryn", "Jothee", "Jothee",
                      "Chiana", "Scorpius", "Scorpius"),
                    species = c("Sebacian", "Luxan", "Sebacian",
                      "Nibari", "Sebacian", "Scarran"),
                    stringsAsFactors = TRUE)
  dfS <- colwise(as.character)(dfF)
  matchF <- data.frame(species = "Sebacian", stringsAsFactors = TRUE)
  matchS <- colwise(as.character)(matchF)

  #nor does `join`, (so inner joins are not commutative)
  expect_equal(3, nrow(join(dfF, matchF, type = "inner", by="species")))
  expect_equal(3, nrow(join(dfS, matchS, type = "inner", by="species")))
  expect_equal(3, nrow(join(dfS, matchF, type = "inner", by="species")))
  expect_equal(3, nrow(join(dfF, matchS, type = "inner", by="species")))

})

test_that("join_all", {

  df <- expand.grid(.id = 1, a = 1:2, b = 4:5, c = letters[1:2], d = letters[4:5],
                    KEEP.OUT.ATTRS = FALSE, stringsAsFactors = FALSE)
  df$.id <- as.integer(rownames(df))
  expect_equal(join_all(list(df)), df)
  expect_equal(join_all(list(df[, c(1,2)], df[, c(1,3,4,5)])), df)
  expect_equal(join_all(list(df[, c(1,2)], df[, c(1,3,4)], df[, c(1,4,5)])), df)

})

test_that("match_df", {

  df <- expand.grid(.id = 1, a = 1:2, b = 4:5, c = letters[1:2], d = letters[4:5],
                    KEEP.OUT.ATTRS = FALSE, stringsAsFactors = FALSE)

  expect_equal(match_df(df, df), df)
  expect_equal(match_df(df, df), df)
  expect_equal(nrow(match_df(df, data.frame(a=1, b=4))), 4)

})