fix: better bipartite type checking

R/attributes.R

@@ -1256,7 +1256,11 @@ is_weighted <- function(graph) {
 is_bipartite <- function(graph) {
   ensure_igraph(graph)
 
-  "type" %in% vertex_attr_names(graph)
+  if (!"type" %in% vertex_attr_names(graph)) {
+    return(FALSE)
+  }
+  type_vals <- vertex_attr(graph, "type")
+  is.logical(type_vals) || !anyNA(as.logical(type_vals))
 }
 
 #############

R/other.R

@@ -159,11 +159,21 @@ handle_vertex_type_arg <- function(types, graph, required = T) {
   }
   if (!is.null(types)) {
     if (!is.logical(types)) {
-      cli::cli_warn("vertex types converted to logical.")
-    }
-    types <- as.logical(types)
-    if (any(is.na(types))) {
-      cli::cli_abort("`NA' is not allowed in vertex types")
+      converted <- suppressWarnings(as.logical(types))
+      if (anyNA(converted)) {
+        cli::cli_abort(
+          "The {.arg type} vertex attribute is not logical and could not be \\
+           converted to logical. Please set it to a logical vector."
+        )
+      }
+      cli::cli_warn(
+        "The {.arg type} vertex attribute is not logical; converting to logical."
+      )
+      types <- converted
+    } else if (anyNA(types)) {
+      cli::cli_abort(
+        "The {.arg type} vertex attribute contains {.val NA} values, which are not allowed."
+      )
     }
   }
   if (is.null(types) && required) {

tests/testthat/test-attributes.R

@@ -303,6 +303,29 @@ test_that("is_bipartite works", {
   )
 })
 
+test_that("is_bipartite checks that type attribute is logical or convertible", {
+  g <- make_ring(4)
+
+  # No type attribute
+  expect_false(is_bipartite(g))
+
+  # Logical type
+  V(g)$type <- c(FALSE, TRUE, FALSE, TRUE)
+  expect_true(is_bipartite(g))
+
+  # Numeric 0/1 is convertible to logical
+  V(g)$type <- c(0, 1, 0, 1)
+  expect_true(is_bipartite(g))
+
+  # Character not convertible via as.logical (produces NAs)
+  V(g)$type <- c("a", "b", "a", "b")
+  expect_false(is_bipartite(g))
+
+  # NA-producing conversion
+  V(g)$type <- c(1L, 2L, 1L, NA_integer_)
+  expect_false(is_bipartite(g))
+})
+
 test_that("without_attr", {
   withr::local_seed(42)
   g_stripped <- sample_gnp(10, 2 / 10) %>%