tests/testthat/_snaps/attributes.md

In igraph: Network Analysis and Visualization

error messages work

Code
  set_vertex_attr(g, "test", value = c(1, 2))
Condition
  Error in `i_set_vertex_attr()`:
  ! Length of new attribute value must be 1 or 5, the number of target vertices, not 2.

Code
  set_edge_attr(g, "test", value = c(1, 2))
Condition
  Error in `i_set_edge_attr()`:
  ! Length of new attribute value must be 1 or 10, the number of target edges, not 2.

Code
  delete_graph_attr(g, "a")
Condition
  Error in `delete_graph_attr()`:
  ! No graph attribute `a` found.

Code
  delete_vertex_attr(g, "a")
Condition
  Error in `delete_vertex_attr()`:
  ! No vertex attribute `a` found.

Code
  delete_edge_attr(g, "a")
Condition
  Error in `delete_edge_attr()`:
  ! No edge attribute `a` found.

Code
  assert_named_list("a")
Condition
  Error in `assert_named_list()`:
  ! `value` must be a named list with unique names

Code
  assert_named_list(list("a", "b"))
Condition
  Error in `assert_named_list()`:
  ! `value` must be a named list with unique names

good error message when not using character

Code
  set_graph_attr(ring, 1, 1)
Condition
  Error in `set_graph_attr()`:
  ! `name` must be a single string, not the number 1.

set_vertex_attrs() works

Code
  set_vertex_attrs(g)
Condition
  Error in `set_vertex_attrs()`:
  ! All arguments in `...` must be named.

igraph documentation built on Feb. 12, 2026, 5:08 p.m.