Allow shortestPath to traverse both relationship directions

The documentation for the graph algorithms endpoint doesn’t mention
that you can do direction=all, but here we are.

Closes #42.

R/allShortestPaths.R

@@ -5,7 +5,7 @@
 #' @param fromNode A node object.
 #' @param relType A character string. The relationship type to traverse.
 #' @param toNode A node object.
-#' @param direction A character string. The relationship direction to traverse. Should be "in" or "out".
+#' @param direction A character string. The relationship direction to traverse; this can be either "in", "out", or "all".
 #' @param max_depth An integer. The maximum depth of the path.
 #' @param cost_property A character string. If retrieving a weighted shortest path, the name of the relationship property that contains the weights.
 #' 

R/internal.R

@@ -170,7 +170,7 @@ cypher_endpoint = function(graph, query, params) {
 shortest_path_algo = function(all, algo, fromNode, relType, toNode, direction = "out", max_depth = 1, cost_property=character()) {
   stopifnot(is.character(relType), 
             "node" %in% class(toNode),
-            direction %in% c("in", "out"),
+            direction %in% c("in", "out", "all"),
             is.numeric(max_depth),
             is.character(cost_property))
 

R/shortestPath.R

@@ -5,7 +5,7 @@
 #' @param fromNode A node object.
 #' @param relType A character string. The relationship type to traverse.
 #' @param toNode A node object.
-#' @param direction A character string. The relationship direction to traverse. Should be "in" or "out".
+#' @param direction A character string. The relationship direction to traverse; this can be either "in", "out", or "all".
 #' @param max_depth An integer. The maximum depth of the path.
 #' @param cost_property A character string. If retrieving a weighted shortest path, the name of the relationship property that contains the weights.
 #' 

man/allShortestPaths.Rd

@@ -14,7 +14,7 @@ allShortestPaths(fromNode, relType, toNode, direction = "out",
 
 \item{toNode}{A node object.}
 
-\item{direction}{A character string. The relationship direction to traverse. Should be "in" or "out".}
+\item{direction}{A character string. The relationship direction to traverse; this can be either "in", "out", or "all".}
 
 \item{max_depth}{An integer. The maximum depth of the path.}
 

man/shortestPath.Rd

@@ -14,7 +14,7 @@ shortestPath(fromNode, relType, toNode, direction = "out", max_depth = 1,
 
 \item{toNode}{A node object.}
 
-\item{direction}{A character string. The relationship direction to traverse. Should be "in" or "out".}
+\item{direction}{A character string. The relationship direction to traverse; this can be either "in", "out", or "all".}
 
 \item{max_depth}{An integer. The maximum depth of the path.}
 

tests/testthat/test-paths.R

@@ -49,6 +49,17 @@ test_that("shortestPath works with direction=in", {
   expect_equal(actual_names, expected_names)
 })
 
+test_that("shortestPath works with direction=all", {
+  p = shortestPath(charles, "WORKS_WITH", elaine, direction = "all", max_depth = 4)
+  expect_is(p, "path")
+  expect_equal(p$length, 2)
+
+  n = nodes(p)
+  actual_names = sapply(n, '[[', 'name')
+  expected_names = c("Charles", "David", "Elaine")
+  expect_equal(actual_names, expected_names)
+})
+
 test_that("allShortestPaths returns null when not found", {
   p = allShortestPaths(alice, "WORKS_WITH", david)
   expect_null(p)
@@ -57,18 +68,27 @@ test_that("allShortestPaths returns null when not found", {
   expect_null(p)
 })
 
-test_that("allShortestPaths works", {
-  p = allShortestPaths(alice, "WORKS_WITH", david, max_depth = 4)
+test_that("allShortestPaths works with direction=out", {
+  p = allShortestPaths(alice, "WORKS_WITH", david, direction = "out", max_depth = 4)
   expect_is(p, "list")
   expect_is(p[[1]], "path")
   expect_equal(length(p), 2)
-
+})
+
+test_that("allShortestPaths works with direction=in", {
   p = allShortestPaths(david, "WORKS_WITH", alice, direction = "in", max_depth = 4)
   expect_is(p, "list")
   expect_is(p[[1]], "path")
   expect_equal(length(p), 2)
 })
 
+test_that("allShortestPaths works with direction=all", {
+  p = allShortestPaths(bob, "WORKS_WITH", elaine, direction = "all", max_depth = 4)
+  expect_is(p, "list")
+  expect_is(p[[1]], "path")
+  expect_equal(length(p), 2)
+})
+
 test_that("shortestPath works with cost property", {
   p = shortestPath(alice, "WORKS_WITH", david, cost_property="weight")