tests/testthat/test-dagitty_nodes_edges.R

In cjvanlissa/tidySEM: Tidy Structural Equation Modeling

if(requireNamespace("dagitty", quietly = TRUE)){
  library(dagitty)
  # Specify a simple DAG containing one path
  g <- dagitty("dag{
a -> b ;
b -> c ;
d -> c
}")
  nod1 <- tidySEM::get_nodes(g)
  edg1 <- tidySEM::get_edges(g)
  # Newlines and semicolons are optional
  g <- dagitty("dag{
a -> b b -> c d -> c
}")
  nod2 <- tidySEM::get_nodes(g)
  edg2 <- tidySEM::get_edges(g)
  test_that("Newlines and semicolons are optional", {
    expect_equal(nod1, nod2)
    expect_equal(edg1, edg2)
  })
  # Paths can be specified in one go; the semicolon below is
  # optional
  g <- dagitty("dag{
a -> b ->c ; d -> c
}")

  nod3 <- tidySEM::get_nodes(g)
  edg3 <- tidySEM::get_edges(g)
  test_that("Paths can be specified in one go", {
    expect_equal(nod1, nod3)
    expect_equal(edg1, edg3)
  })

  # Edges can be written in reverse notation
  g <- dagitty("dag{
a -> b -> c <- d
}")

  nod4 <- tidySEM::get_nodes(g)
  edg4 <- tidySEM::get_edges(g)
  test_that("Edges can be written in reverse notation", {
    expect_equal(nod1, nod4)
    expect_equal(edg1, edg4)
  })
  # Spaces are optional as well
  g <- dagitty("dag{a->b->c<-d}")
  nod5 <- tidySEM::get_nodes(g)
  edg5 <- tidySEM::get_edges(g)
  test_that("Spaces are optional as well", {
    expect_equal(nod1, nod5)
    expect_equal(edg1, edg5)
  })
  # Variable attributes can be set in square brackets
  # Example: DAG with one exposure, one outcome, and one unobserved variable
  g <- dagitty("dag{
x -> y ; x <- z -> y
x [exposure]
y [outcome]
z [unobserved]
}")

  nod6 <- tidySEM::get_nodes(g)
  edg6 <- tidySEM::get_edges(g)
  test_that("Node attributes are detected", {
    expect_true(nod6$exposure[nod6$name =="x"])
    expect_true(nod6$outcome[nod6$name =="y"])
    expect_true(nod6$latent[nod6$name =="z"])
  })

  # The same graph as above
  g <- dagitty("dag{x[e]y[o]z[u]x<-z->y<-x}")
  nod7 <- tidySEM::get_nodes(g)
  edg7 <- tidySEM::get_edges(g)
  test_that("Abbreviated node attributes are detected", {
    expect_true(nod7$exposure[nod6$name =="x"])
    expect_true(nod7$outcome[nod6$name =="y"])
    expect_true(nod7$latent[nod6$name =="z"])
  })


  g <- dagitty('dag{
x -> y ; x <- z -> y
x [exposure,pos="0,1"]
y [outcome, pos = "1,1"]
z [unobserved , pos = "1 , 0"]
}')

  nod8 <- tidySEM::get_nodes(g)
  edg8 <- tidySEM::get_edges(g)
  test_that("Node attributes are detected", {
    expect_true(nod6$exposure[nod6$name =="x"])
    expect_true(nod6$outcome[nod6$name =="y"])
    expect_true(nod6$latent[nod6$name =="z"])
  })

}