tests/testthat/test-cypher.R

In RNeo4j: Neo4j Driver for R

library(RNeo4j)
context("Cypher")

skip_on_cran()

options(digits=20)

neo4j = startGraph("http://localhost:7474/db/data/", "neo4j", "password")
importSample(neo4j, "dfw", input=F)

test_that("cypher works", {
  options(stringsAsFactors=F)
  expected = data.frame(terminal = c("A", "B", "C", "D", "E"))
  actual = cypher(neo4j, "MATCH (t:Terminal) RETURN t.name AS terminal ORDER BY terminal")
  expect_identical(actual, expected)
})

test_that("cypher retrieves arrays correctly", {
  query = "
  MATCH (p:Place)-[:IN_CATEGORY]->(c:Category)
  RETURN c.name AS category, COLLECT(p.name) AS places
  "
  
  data = cypher(neo4j, query)
  classes = sapply(data, class)
  expect_true("list" %in% classes)
})

test_that("cypher works with parameters", {
  query = "MATCH (t:Terminal) WHERE t.name = {terminal} RETURN t.name"
  data = cypher(neo4j, query, terminal="A")
  expect_equal(data[1, 1], "A")
})

test_that("cypher works with array parameters", {
  query = "MATCH (t:Terminal) WHERE t.name IN {terminals} RETURN t.name"
  data = cypher(neo4j, query, terminals=c("A", "B"))
  expect_equal(nrow(data), 2)
})

test_that("cypher doesn't round numeric parameters", {
  NUMBER = 123456789
  query = "RETURN {number}"
  data = cypher(neo4j, query, number=NUMBER)
  expect_equal(data[1, 1], NUMBER)
})

test_that("cypher handles nulls correctly", {
  expected = data.frame(
    n.thing = c(
      rep(NA, 10)
    )
  )
  actual = cypher(neo4j, "MATCH n RETURN n.thing LIMIT 10")
  expect_identical(actual, expected)
})

test_that("cypher won't return graph results - paths", {
  q = "MATCH p = ()-[]-() RETURN p, LENGTH(p) LIMIT 2"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
  q = "MATCH p = ()-[]-() RETURN LENGTH(p), p"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
})

test_that("cypher won't return graph results - nodes", {
  q = "MATCH n WITH n LIMIT 2 RETURN n.name, n"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
  q = "MATCH n WITH n LIMIT 2 RETURN n, n.name"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
})

test_that("cypher won't return graph results - relationships", {
  q = "MATCH ()-[r]-() WITH r LIMIT 2 RETURN r.name, r"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
  q = "MATCH ()-[r]-() WITH r LIMIT 2 RETURN r, r.name"
  expect_error(cypher(neo4j, q), "You must query for tabular results when using this function.")
})

test_that("cypher throws error on invalid query", {
  expect_error(cypher(neo4j, "MATCH n RETURN m"))
})

test_that("it works with multiple parameters", {
  query = "
  MATCH (g:Gate)-[:IN_TERMINAL]->(t:Terminal) 
  WHERE g.gate = {gate} AND t.name = {terminal}
  RETURN g.gate
  "
  
  data = cypher(neo4j, query, gate=4, terminal="A")
  expect_equal(data[1, 1], 4)
})

test_that("it works with a list of parameters", {
  query = "
  MATCH (g:Gate)-[:IN_TERMINAL]->(t:Terminal) 
  WHERE g.gate = {gate} AND t.name = {terminal}
  RETURN g.gate
  "
  
  data = cypher(neo4j, query, list(gate=4, terminal="A"))
  expect_equal(data[1, 1], 4)
})