add documentation, visualizer now returns string, clean test

Cargo.toml

@@ -6,7 +6,6 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-rand = "0.8.5"
 
 [dev-dependencies]
 rand = "0.8.5"

src/tools/graph_visualizer.rs

@@ -1,13 +1,36 @@
 use crate::data_structures::{graph::Graph, subgraph::Subgraph};
 
-use rand::{seq::IteratorRandom, thread_rng};
-use std::{
-    fs::File,
-    io::{Error, Write},
-};
+/// Generates a .dot file for the given graph. The subgraphs are colored in the order they are given.
+///
+/// # Example
+/// ```
+/// use star::data_structures::{graph::Graph, choice_dict::ChoiceDict, subgraph::Subgraph};
+/// use star::tools::graph_visualizer::dot_graph;
+/// let graph = Graph::new_with_edges(
+///     6,
+///     vec![
+///         [3, 2].to_vec(),
+///         [4, 2, 5].to_vec(),
+///         [0, 1].to_vec(),
+///         [0, 5].to_vec(),
+///         [1].to_vec(),
+///         [1, 3].to_vec(),
+///     ],
+/// );
+/// let mut subset = ChoiceDict::new(graph.nodes.len());
+/// subset.set(0);
+/// subset.set(3);
+/// subset.set(4);
+/// let mut subset1 = ChoiceDict::new(graph.nodes.len());
+/// subset1.set(1);
+/// subset1.set(2);
+/// let sub = Subgraph::new(&graph, subset);
+/// let sub1 = Subgraph::new(&graph, subset1);
+/// dot_graph(&graph, vec![sub, sub1]);
+/// ```
 
-pub fn dot_graph(graph: &Graph, filename: &str, subgraphs: Vec<Subgraph>) -> Result<(), Error> {
-    let mut graph_string = String::from("graph {\n");
+pub fn dot_graph(graph: &Graph, subgraphs: Vec<Subgraph>) -> String {
+    let mut graph_string = String::from("graph {");
     let mut already_written: Vec<(usize, usize)> = Vec::new();
     let mut nodes_visited: Vec<bool> = vec![false; graph.nodes.len()];
     let available_colors = ["red", "green", "blue", "yellow", "orange", "purple"];
@@ -17,7 +40,7 @@ pub fn dot_graph(graph: &Graph, filename: &str, subgraphs: Vec<Subgraph>) -> Res
                 already_written.push((i, *j));
                 nodes_visited[i] = true;
                 nodes_visited[*j] = true;
-                graph_string.push_str(&format!("\t{} -- {};\n", i, j));
+                graph_string.push_str(&format!("{} -- {};", i, j));
             }
         })
     });
@@ -27,32 +50,29 @@ pub fn dot_graph(graph: &Graph, filename: &str, subgraphs: Vec<Subgraph>) -> Res
         .enumerate()
         .filter(|v| !*v.1)
         .map(|(i, _)| i)
-        .for_each(|v| graph_string.push_str(&format!("\t{};\n", v)));
+        .for_each(|v| graph_string.push_str(&format!("{};", v)));
 
     subgraphs.iter().enumerate().for_each(|(i, sg)| {
-        let color = available_colors.iter().choose(&mut thread_rng()).unwrap();
-        graph_string.push_str(&format!("\tsubgraph cluster_{} {{\n\t\tstyle=invis;\n", i));
+        let color = available_colors[i % available_colors.len()];
+        graph_string.push_str(&format!("subgraph cluster_{} {{style=invis;", i));
         sg.subset.iter_1().for_each(|v| {
-            graph_string.push_str(&format!("\t\t{} [fillcolor={}, style=filled];\n", v, color));
+            graph_string.push_str(&format!("{} [fillcolor={}, style=filled];", v, color));
         });
-        graph_string.push_str("\t}\n");
+        graph_string.push('}');
     });
 
     graph_string.push('}');
-    File::create(filename)?.write_all(graph_string.as_bytes())?;
 
-    Ok(())
+    graph_string
 }
 
-#[cfg(test)]
 mod tests {
-    use crate::data_structures::{choice_dict::ChoiceDict, subgraph::Subgraph};
 
     #[test]
-    #[cfg(not(miri))]
     fn test_dot_graph() {
         use super::dot_graph;
         use crate::data_structures::graph::Graph;
+        use crate::data_structures::{choice_dict::ChoiceDict, subgraph::Subgraph};
         let graph = Graph::new_with_edges(
             6,
             vec![
@@ -75,6 +95,6 @@ mod tests {
 
         let sub = Subgraph::new(&graph, subset);
         let sub1 = Subgraph::new(&graph, subset1);
-        dot_graph(&graph, "test.dot", vec![sub, sub1]).unwrap();
+        assert_eq!(dot_graph(&graph, vec![sub, sub1]), "graph {0 -- 3;0 -- 2;1 -- 4;1 -- 2;5;subgraph cluster_0 {style=invis;0 [fillcolor=red, style=filled];3 [fillcolor=red, style=filled];4 [fillcolor=red, style=filled];}subgraph cluster_1 {style=invis;1 [fillcolor=green, style=filled];2 [fillcolor=green, style=filled];}}");
     }
 }