tests/testthat/test_join.R

In matthieugomez/statar: Tools Inspired by 'Stata' to Manipulate Tabular Data

library(statar)
context("join")


library(data.table)
a <- data.table(x = c(1, 1, 2, 3), y = 1:4)
b <- data.table(x = c(1, 2, 2, 4), z = 1:4)

test_that("univariate inner join has all columns, repeated matching rows", {
  j <- join(a, b, "x", kind = "inner")

  expect_equal(names(j), c("x", "y", "z"))
  expect_equal(j$y, c(1, 2, 3, 3))
  expect_equal(j$z, c(1, 1, 2, 3))
})

test_that("univariate left join has all columns, all rows", {
  j1 <- join(a, b, "x", kind = "left")
  j2 <- join(b, a, "x", kind = "left")

  expect_equal(names(j1), c("x", "y", "z"))
  expect_equal(names(j2), c("x", "z", "y"))

  expect_equal(j1$z, c(1, 1, 2, 3, NA))
  expect_equal(j2$y, c(1, 2, 3, 3, NA))
})

test_that("univariate semi join has x columns, matching rows", {
  j1 <- join(a, b, "x", kind = "semi")
  j2 <- join(b, a, "x", kind = "semi")

  expect_equal(names(j1), c("x", "y"))
  expect_equal(names(j2), c("x", "z"))

  expect_equal(j1$y, 1:3)
  expect_equal(j2$z, 1:3)
})

test_that("univariate anti join has x columns, missing rows", {
  j1 <- join(a, b, "x", kind = "anti")
  j2 <- join(b, a, "x", kind = "anti")

  expect_equal(names(j1), c("x", "y"))
  expect_equal(names(j2), c("x", "z"))

  expect_equal(j1$y, 4)
  expect_equal(j2$z, 4)
})

# Bivariate keys ---------------------------------------------------------------

c <- data.table(
  x = c(1, 1, 2, 3),
  y = c(1, 1, 2, 3),
  a = 1:4)
d <- data.table(
  x = c(1, 2, 2, 4),
  y = c(1, 2, 2, 4),
  b = 1:4)

test_that("bivariate inner join has all columns, repeated matching rows", {
  j <- join(c, d, c("x", "y"), kind = "inner")

  expect_equal(names(j), c("x", "y", "a", "b"))
  expect_equal(j$a, c(1, 2, 3, 3))
  expect_equal(j$b, c(1, 1, 2, 3))
})

test_that("bivariate left join has all columns, all rows", {
  j1 <- join(c, d, c("x", "y"), kind = "left")
  j2 <- join(d, c, c("x", "y"), kind = "left")

  expect_equal(names(j1), c("x", "y", "a", "b"))
  expect_equal(names(j2), c("x", "y", "b", "a"))

  expect_equal(j1$b, c(1, 1, 2, 3, NA))
  expect_equal(j2$a, c(1, 2, 3, 3, NA))
})

test_that("bivariate semi join has x columns, matching rows", {
  j1 <- join(c, d, c("x", "y"), kind = "semi")
  j2 <- join(d, c, c("x", "y"), kind = "semi")

  expect_equal(names(j1), c("x", "y", "a"))
  expect_equal(names(j2), c("x", "y", "b"))

  expect_equal(j1$a, 1:3)
  expect_equal(j2$b, 1:3)
})

test_that("bivariate anti join has x columns, missing rows", {
  j1 <- join(c, d, c("x", "y"), kind = "anti")
  j2 <- join(d, c, c("x", "y"), kind = "anti")

  expect_equal(names(j1), c("x", "y", "a"))
  expect_equal(names(j2), c("x", "y", "b"))

  expect_equal(j1$a, 4)
  expect_equal(j2$b, 4)
})

# Test the merge variable (gen = "m") -------------------------------------

test_that("the merge variable column correctly mark results", {
    j <- join(a, b, "x", kind = "full", gen = "m") 
    
    master_df  <- join(a, b, "x", kind = "anti")
    using_df   <- join(b, a, "x", kind = "anti")
    matched_df <- join(a, b, "x", kind = "inner")
    
    j1 <- join(j, master_df, kind = "right")
    j2 <- join(j, using_df, kind = "right")
    j3 <- join(j, matched_df, kind = "right")
    
    expect_equal(unique(j1$m), 1)
    expect_equal(unique(j2$m), 2)
    expect_equal(unique(j3$m), 3)
})

test_that("if left join, the merge variable should not contain value 2", {
    j1 <- join(a, a, "x", kind = "left", gen = "m")
    j2 <- join(a, b, "x", kind = "left", gen = "m")
    
    m1 <- j1$m
    m2 <- j2$m
    
    expect_true(all(unique(m1) %in% c(1L, 3L)))
    expect_true(all(unique(m2) %in% c(1L, 3L)))
})

test_that("if right join, the merge variable should not contain value 1", {
    j1 <- join(a, a, "x", kind = "right", gen = "m")
    j2 <- join(a, b, "x", kind = "right", gen = "m")
    
    m1 <- j1$m
    m2 <- j2$m
    
    expect_true(all(unique(m1) %in% c(2L, 3L)))
    expect_true(all(unique(m2) %in% c(2L, 3L)))
})

# Test the key integrity check -------------------------------------

e <- as.data.frame(c)
f <- as.data.frame(d)

test_that("the check correctly interprets duplicated identifiers", {
  expect_error(join(e, f, c("x", "y"), kind = "full", check = 1~m), ".*x$")
  expect_error(join(e, f, c("x", "y"), kind = "full", check = m~1), ".*y$")
})