Fix #113

NAMESPACE

@@ -166,6 +166,7 @@ export(dfs_rank_out)
 export(distinct)
 export(drop_na)
 export(edge_is_between)
+export(edge_is_bridge)
 export(edge_is_from)
 export(edge_is_incident)
 export(edge_is_loop)
@@ -449,6 +450,7 @@ importFrom(igraph,betweenness)
 importFrom(igraph,bfs)
 importFrom(igraph,bibcoupling)
 importFrom(igraph,biconnected_components)
+importFrom(igraph,bridges)
 importFrom(igraph,clique_num)
 importFrom(igraph,closeness)
 importFrom(igraph,cluster_edge_betweenness)

NEWS.md

@@ -9,6 +9,7 @@
   (#152)
 * Added the whole family of `slice_*()` functions from dplyr (#128)
 * Added methods for `tidyr::replace_na()` and `tidyr::drop_na()` (#114)
+* Added `edge_is_bridge()` for querying whether an edge is a bridge edge (#113)
 
 # tidygraph 1.2.3
 

R/edge.R

@@ -81,4 +81,13 @@ edge_is_incident <- function(nodes) {
   nodes <- as_ind(nodes, graph_order())
   edges$from %in% nodes | edges$to %in% nodes
 }
+#' @describeIn edge_types Query whether an edge is a bridge (ie. it's removal
+#' will increase the number of components in a graph)
+#' @importFrom igraph bridges gsize
+#' @export
+edge_is_bridge <- function() {
+  expect_edges()
+  graph <- .G()
+  seq_len(gsize(graph)) %in% bridges(graph)
 }
+

tests/testthat/test-edge_types.R

@@ -11,6 +11,7 @@ test_that("edge types return logical", {
   expect_type(get_type(gr, edge_is_loop()), 'logical')
   expect_type(get_type(gr, edge_is_multiple()), 'logical')
   expect_type(get_type(gr, edge_is_mutual()), 'logical')
+  expect_type(get_type(gr, edge_is_bridge()), 'logical')
 })
 test_that("edge types return correct length", {
   gr <- create_notable('bull') %>%
@@ -22,6 +23,7 @@ test_that("edge types return correct length", {
   expect_length(get_type(gr, edge_is_loop()), igraph::gsize(gr))
   expect_length(get_type(gr, edge_is_multiple()), igraph::gsize(gr))
   expect_length(get_type(gr, edge_is_mutual()), igraph::gsize(gr))
+  expect_length(get_type(gr, edge_is_bridge()), igraph::gsize(gr))
 })
 test_that("edge types require edge active", {
   gr <- create_notable('bull') %>%
@@ -33,4 +35,5 @@ test_that("edge types require edge active", {
   expect_error(get_type(gr, edge_is_loop()))
   expect_error(get_type(gr, edge_is_multiple()))
   expect_error(get_type(gr, edge_is_mutual()))
+  expect_error(get_type(gr, edge_is_bridge()))
 })