tests/testthat/TestFunctions.R

In TheBell/Graph:

# Utility functions for parsing test files

#' A function to parse the header of a graph
#'
#' @param con A connection to a test file
#' @param useAdjMatrix TRUE if implementing graph is adj matrix
#' @return a graph object with base attributes set
buildGraph <- function(con, useAdjMatrix = TRUE) {
  weighted <- FALSE
  directed <- FALSE

  line <- readLines(con, n = 1)

  # Read through header
  while (line != "begin") {
    if (length(line) == 0) break  # EOF

    line <- readLines(con, n = 1)

    if (grepl("^\\*.*$", line)) next  # skip comments

    if (grepl("^weighted", line)) weighted <- TRUE

    if (grepl("^directed", line)) directed <- TRUE
  }

  # Get Nodes
  line <- readLines(con, n = 1)
  nodes <- unlist(strsplit(line, split = " "))
  return(graph(nodes, weighted = weighted, directed = directed, useAdjMatrix))
}

#' A function to add edges from test file into graph
#'
#' @param con A connection to a test file
#' @return a graph object with the edges added
addEdges <- function(con, graph) {
  while (TRUE) {
    line <- readLines(con, n = 1)

    if (length(line) == 0) break  # EOF
    if (line == "end") break

    weight <- 1  # Default for edges, if not specified

    edge <- unlist(strsplit(line, split = " "))

    if (length(edge) > 3) weight <- edge[3]

    graph <- addEdge(graph, edge[1], edge[2], weight)[[1]]
  }

  return(graph)
}


#'A function to run the tests in the file
#'
#'@param graphObj the graph object to run the method on
#'@param methodStr a string with the name of the method
#'@param expected the expected output
#'@param args arguments to pass to the method
runTest <- function(graphObj, methodStr, expected, args) {

  fun <- get(methodStr)  # Get the function to call
  # print(fun)
  result <- do.call(fun, c(list(graphObj), args))
  if (result[[2]] != expected) {
    print(paste("Function:", methodStr, "failed."))
    print(paste("Expected:", expected, "Result:", result[[2]]))
  }
  expect_equal(result[[2]], expected)
  return(result[[1]])  # Return the graph
}