support Into<String> in more scenarios to remove the need for users to always have to perform a .to_string

5 files changed, 152 insertions, 136 deletions

diff --git a/README.md b/README.md
index a8327b9..b25bff4 100644
--- a/README.md
+++ b/README.md
@@ -22,11 +22,11 @@ use dotavious::{Dot, Edge, Graph, GraphBuilder, Node};
 use std::io;
 use std::io::Read;
 
-// can also start building a undirected graph via `GraphBuilder::new_undirected`
-let graph = GraphBuilder::new_directed(Some("example".to_string()))
-        .add_node(Node::new("N0".to_string()))
-        .add_node(Node::new("N1".to_string()))
-        .add_edge(Edge::new("N0".to_string(), "N1".to_string()))
+// can also start building a named undirected graph via `GraphBuilder::new_named_undirected`
+let graph = GraphBuilder::new_named_directed("example")
+        .add_node(Node::new("N0"))
+        .add_node(Node::new("N1"))
+        .add_edge(Edge::new("N0", "N1"))
         .build()
         .unwrap();
 
@@ -42,4 +42,5 @@ digraph example {
 }
 ```
 and when rendered will look like
+
 ![README example rendered](readme-example.png?raw=true)
diff --git a/src/attributes/mod.rs b/src/attributes/mod.rs
index 0cdfa99..94ade1b 100644
--- a/src/attributes/mod.rs
+++ b/src/attributes/mod.rs
@@ -495,7 +495,7 @@ pub trait GraphAttributes<'a> {
     }
 
     /// An escString or an HTML label.
-    fn label(&mut self, label: String) -> &mut Self {
+    fn label<S: Into<String>>(&mut self, label: S) -> &mut Self {
         Attributes::label(self.get_attributes_mut(), label);
         self
     }
@@ -1047,8 +1047,8 @@ impl Attributes {
         )
     }
 
-    pub fn label(attributes: &mut IndexMap<String, AttributeText>, text: String) {
-        Self::add_attribute(attributes, "label", AttributeText::quoted(text));
+    pub fn label<S: Into<String>>(attributes: &mut IndexMap<String, AttributeText>, text: S) {
+        Self::add_attribute(attributes, "label", AttributeText::quoted(text.into()));
     }
 
     pub fn label_location(
diff --git a/src/dot.rs b/src/dot.rs
index a6828b7..f154dc9 100644
--- a/src/dot.rs
+++ b/src/dot.rs
@@ -316,26 +316,26 @@ pub struct GraphBuilder<'a> {
 
 // TODO: id should be an escString
 impl<'a> GraphBuilder<'a> {
-    pub fn new_directed(id: Option<String>) -> Self {
-        Self {
-            id,
-            is_directed: true,
-            strict: false,
-            graph_attributes: IndexMap::new(),
-            node_attributes: IndexMap::new(),
-            edge_attributes: IndexMap::new(),
-            sub_graphs: Vec::new(),
-            nodes: Vec::new(),
-            edges: Vec::new(),
-            comment: None,
-            errors: Vec::new(),
-        }
+    pub fn new_directed() -> Self {
+        Self::new(None, true)
+    }
+
+    pub fn new_named_directed<S: Into<String>>(id: S) -> Self {
+        Self::new(Some(id.into()), true)
+    }
+
+    pub fn new_undirected() -> Self {
+        Self::new(None, false)
+    }
+
+    pub fn new_named_undirected<S: Into<String>>(id: S) -> Self {
+        Self::new(Some(id.into()), false)
     }
 
-    pub fn new_undirected(id: Option<String>) -> Self {
+    fn new(id: Option<String>, is_directed: bool) -> Self {
         Self {
             id,
-            is_directed: false,
+            is_directed,
             strict: false,
             graph_attributes: IndexMap::new(),
             node_attributes: IndexMap::new(),
@@ -377,16 +377,16 @@ impl<'a> GraphBuilder<'a> {
         self
     }
 
-    pub fn add_attribute(
+    pub fn add_attribute<S: Into<String>>(
         &mut self,
         attribute_type: AttributeType,
-        key: String,
+        key: S,
         value: AttributeText<'a>,
     ) -> &mut Self {
         match attribute_type {
-            AttributeType::Graph => self.graph_attributes.insert(key, value),
-            AttributeType::Edge => self.edge_attributes.insert(key, value),
-            AttributeType::Node => self.node_attributes.insert(key, value),
+            AttributeType::Graph => self.graph_attributes.insert(key.into(), value),
+            AttributeType::Edge => self.edge_attributes.insert(key.into(), value),
+            AttributeType::Node => self.node_attributes.insert(key.into(), value),
         };
         self
     }
@@ -503,9 +503,16 @@ pub struct SubGraphBuilder<'a> {
     errors: Vec<ValidationError>,
 }
 
-// TODO: id should be an escString
 impl<'a> SubGraphBuilder<'a> {
-    pub fn new(id: Option<String>) -> Self {
+    pub fn new() -> Self {
+        Self::new_inner(None)
+    }
+
+    pub fn new_named<S: Into<String>>(id: S) -> Self {
+        Self::new_inner(Some(id.into()))
+    }
+
+    fn new_inner(id: Option<String>) -> Self {
         Self {
             id,
             graph_attributes: IndexMap::new(),
@@ -620,10 +627,10 @@ pub struct Node<'a> {
 }
 
 impl<'a> Node<'a> {
-    pub fn new(id: String) -> Node<'a> {
+    pub fn new<S: Into<String>>(id: S) -> Node<'a> {
         // TODO: constrain id
         Node {
-            id,
+            id: id.into(),
             attributes: IndexMap::new(),
         }
     }
@@ -676,9 +683,9 @@ impl<'a> NodeAttributes<'a> for NodeBuilder<'a> {
 }
 
 impl<'a> NodeBuilder<'a> {
-    pub fn new(id: String) -> Self {
+    pub fn new<S: Into<String>>(id: S) -> Self {
         Self {
-            id,
+            id: id.into(),
             attributes: IndexMap::new(),
             errors: Vec::new(),
         }
@@ -710,26 +717,34 @@ pub struct Edge<'a> {
 }
 
 impl<'a> Edge<'a> {
-    pub fn new(source: String, target: String) -> Self {
+    pub fn new<S, T>(source: S, target: T) -> Self
+    where
+        S: Into<String>,
+        T: Into<String>
+    {
         Self {
-            source,
+            source: source.into(),
             source_port_position: None,
-            target,
+            target: target.into(),
             target_port_position: None,
             attributes: IndexMap::new(),
         }
     }
 
-    pub fn new_with_position(
-        source: String,
+    pub fn new_with_position<S, T>(
+        source: S,
         source_port_position: PortPosition,
-        target: String,
+        target: T,
         target_port_position: PortPosition,
-    ) -> Self {
+    ) -> Self
+    where
+        S: Into<String>,
+        T: Into<String>
+    {
         Self {
-            source,
+            source: source.into(),
             source_port_position: Some(source_port_position),
-            target,
+            target: target.into(),
             target_port_position: Some(target_port_position),
             attributes: IndexMap::new(),
         }
@@ -768,10 +783,10 @@ impl<'a> EdgeAttributes<'a> for EdgeBuilder<'a> {
 }
 
 impl<'a> EdgeBuilder<'a> {
-    pub fn new(source: String, target: String) -> Self {
+    pub fn new<S: Into<String>, T: Into<String>>(source: S, target: T) -> Self {
         Self {
-            source,
-            target,
+            source: source.into(),
+            target: target.into(),
             source_port_position: None,
             target_port_position: None,
             attributes: IndexMap::new(),
@@ -779,15 +794,15 @@ impl<'a> EdgeBuilder<'a> {
         }
     }
 
-    pub fn new_with_port_position(
-        source: String,
+    pub fn new_with_port_position<S: Into<String>, T: Into<String>>(
+        source: S,
         source_port_position: PortPosition,
-        target: String,
+        target: T,
         target_port_position: PortPosition,
     ) -> Self {
         Self {
-            source,
-            target,
+            source: source.into(),
+            target: target.into(),
             source_port_position: Some(source_port_position),
             target_port_position: Some(target_port_position),
             attributes: IndexMap::new(),
diff --git a/src/lib.rs b/src/lib.rs
index 3c4b2b1..b39ed4b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,7 +2,7 @@
 #![cfg_attr(docsrs, deny(broken_intra_doc_links))]
 
 //! Dotavious provides bindings to generate [DOT](https://graphviz.org/doc/info/lang.html)
-//! code used by the Graphviz (http://graphviz.org/) for visualising graphs.
+//! code used by the [Graphviz](http://graphviz.org/) for visualising graphs.
 //! It also provides strongly typed attribute functions and offers almost complete
 //! coverage of all Graphviz attributes and syntax.
 //!
@@ -14,10 +14,10 @@
 //! ```rust
 //! use dotavious::{Dot, Edge, Graph, GraphBuilder, Node};
 //!
-//! let g = GraphBuilder::new_directed(Some("example".to_string()))
-//!         .add_node(Node::new("N0".to_string()))
-//!         .add_node(Node::new("N1".to_string()))
-//!         .add_edge(Edge::new("N0".to_string(), "N1".to_string()))
+//! let g = GraphBuilder::new_named_directed("example")
+//!         .add_node(Node::new("N0"))
+//!         .add_node(Node::new("N1"))
+//!         .add_edge(Edge::new("N0", "N1"))
 //!         .build()
 //!         .unwrap();
 //!
@@ -39,7 +39,7 @@
 //! use std::io;
 //! use std::io::Read;
 //!
-//! let g = GraphBuilder::new_directed(Some("example".to_string()))
+//! let g = GraphBuilder::new_named_directed("example")
 //!         .add_node(Node::new("N0".to_string()))
 //!         .add_node(Node::new("N1".to_string()))
 //!         .add_edge(Edge::new("N0".to_string(), "N1".to_string()))
@@ -74,10 +74,10 @@
 //! use std::io;
 //! use std::io::Read;
 //!
-//! let cluster_0 = SubGraphBuilder::new(Some("cluster_0".to_string()))
+//! let cluster_0 = SubGraphBuilder::new_named("cluster_0")
 //!     .add_graph_attributes(
 //!         GraphAttributeStatementBuilder::new()
-//!             .label("process #1".to_string())
+//!             .label("process #1")
 //!             .style(GraphStyle::Filled)
 //!             .color(Color::Named("lightgrey"))
 //!             .build()
@@ -90,16 +90,16 @@
 //!             .build()
 //!             .unwrap(),
 //!     )
-//!     .add_edge(Edge::new("a0".to_string(), "a1".to_string()))
-//!     .add_edge(Edge::new("a1".to_string(), "a2".to_string()))
-//!     .add_edge(Edge::new("a2".to_string(), "a3".to_string()))
+//!     .add_edge(Edge::new("a0", "a1"))
+//!     .add_edge(Edge::new("a1", "a2"))
+//!     .add_edge(Edge::new("a2", "a3"))
 //!     .build()
 //!     .unwrap();
 //!
-//! let cluster_1 = SubGraphBuilder::new(Some("cluster_1".to_string()))
+//! let cluster_1 = SubGraphBuilder::new_named("cluster_1")
 //!     .add_graph_attributes(
 //!         GraphAttributeStatementBuilder::new()
-//!             .label("process #2".to_string())
+//!             .label("process #2")
 //!             .style(GraphStyle::Filled)
 //!             .color(Color::Named("blue"))
 //!             .build()
@@ -111,13 +111,13 @@
 //!             .build()
 //!             .unwrap(),
 //!     )
-//!     .add_edge(Edge::new("b0".to_string(), "b1".to_string()))
-//!     .add_edge(Edge::new("b1".to_string(), "b2".to_string()))
-//!     .add_edge(Edge::new("b2".to_string(), "b3".to_string()))
+//!     .add_edge(Edge::new("b0", "b1"))
+//!     .add_edge(Edge::new("b1", "b2"))
+//!     .add_edge(Edge::new("b2", "b3"))
 //!     .build()
 //!     .unwrap();
 //!
-//! let g = GraphBuilder::new_directed(Some("G".to_string()))
+//! let g = GraphBuilder::new_named_directed("G")
 //!     .add_node(
 //!         NodeBuilder::new("start".to_string())
 //!             .shape(Shape::Mdiamond)
@@ -125,20 +125,20 @@
 //!             .unwrap(),
 //!     )
 //!     .add_node(
-//!         NodeBuilder::new("end".to_string())
+//!         NodeBuilder::new("end")
 //!             .shape(Shape::Msquare)
 //!             .build()
 //!             .unwrap(),
 //!     )
 //!     .add_sub_graph(cluster_0)
 //!     .add_sub_graph(cluster_1)
-//!     .add_edge(Edge::new("start".to_string(), "a0".to_string()))
-//!     .add_edge(Edge::new("start".to_string(), "b0".to_string()))
-//!     .add_edge(Edge::new("a1".to_string(), "b3".to_string()))
-//!     .add_edge(Edge::new("b2".to_string(), "a3".to_string()))
-//!     .add_edge(Edge::new("a3".to_string(), "a0".to_string()))
-//!     .add_edge(Edge::new("a3".to_string(), "end".to_string()))
-//!     .add_edge(Edge::new("b3".to_string(), "end".to_string()))
+//!     .add_edge(Edge::new("start", "a0"))
+//!     .add_edge(Edge::new("start", "b0"))
+//!     .add_edge(Edge::new("a1", "b3"))
+//!     .add_edge(Edge::new("b2", "a3"))
+//!     .add_edge(Edge::new("a3", "a0"))
+//!     .add_edge(Edge::new("a3", "end"))
+//!     .add_edge(Edge::new("b3", "end"))
 //!     .build();
 //! ```
 //!
diff --git a/tests/dot.rs b/tests/dot.rs
index fbfd935..bf960a9 100644
--- a/tests/dot.rs
+++ b/tests/dot.rs
@@ -23,7 +23,7 @@ fn test_input(g: Graph) -> io::Result<String> {
 
 #[test]
 fn empty_digraph_without_id() {
-    let g = GraphBuilder::new_directed(None).build().unwrap();
+    let g = GraphBuilder::new_directed().build().unwrap();
     let r = test_input(g);
     assert_eq!(
         r.unwrap(),
@@ -35,7 +35,7 @@ fn empty_digraph_without_id() {
 
 #[test]
 fn support_display() {
-    let g = GraphBuilder::new_directed(None).build().unwrap();
+    let g = GraphBuilder::new_directed().build().unwrap();
     let dot = Dot { graph: g };
 
     assert_eq!(
@@ -48,7 +48,7 @@ fn support_display() {
 
 #[test]
 fn graph_comment() {
-    let g = GraphBuilder::new_directed(None)
+    let g = GraphBuilder::new_directed()
         .comment("Comment goes here")
         .build()
         .unwrap();
@@ -64,7 +64,7 @@ digraph {
 
 #[test]
 fn empty_digraph() {
-    let g = GraphBuilder::new_directed(Some("empty_graph".to_string()))
+    let g = GraphBuilder::new_named_directed("empty_graph")
         .build()
         .unwrap();
     let r = test_input(g);
@@ -78,7 +78,7 @@ fn empty_digraph() {
 
 #[test]
 fn empty_undirected_graph() {
-    let g = GraphBuilder::new_undirected(Some("empty_graph".to_string()))
+    let g = GraphBuilder::new_named_undirected("empty_graph")
         .build()
         .unwrap();
     let r = test_input(g);
@@ -92,8 +92,8 @@ fn empty_undirected_graph() {
 
 #[test]
 fn single_node() {
-    let g = GraphBuilder::new_directed(Some("single_node".to_string()))
-        .add_node(Node::new("N0".to_string()))
+    let g = GraphBuilder::new_named_directed("single_node")
+        .add_node(Node::new("N0"))
         .build()
         .unwrap();
     let r = test_input(g);
@@ -108,12 +108,12 @@ fn single_node() {
 
 #[test]
 fn single_node_with_style() {
-    let node = NodeBuilder::new("N0".to_string())
+    let node = NodeBuilder::new("N0")
         .style(NodeStyle::Dashed)
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("single_node".to_string()))
+    let g = GraphBuilder::new_named_directed("single_node")
         .add_node(node)
         .build()
         .unwrap();
@@ -130,10 +130,10 @@ fn single_node_with_style() {
 
 #[test]
 fn support_non_inline_builder() {
-    let mut g = GraphBuilder::new_directed(Some("single_node".to_string()));
+    let mut g = GraphBuilder::new_named_directed("single_node");
 
     // TODO: having to split this is stupid. am i doing something wrong?
-    let mut node_builder = NodeBuilder::new("N0".to_string());
+    let mut node_builder = NodeBuilder::new("N0");
     node_builder.style(NodeStyle::Dashed);
 
     if true {
@@ -155,12 +155,12 @@ fn support_non_inline_builder() {
 
 #[test]
 fn builder_support_shape() {
-    let node = NodeBuilder::new("N0".to_string())
+    let node = NodeBuilder::new("N0")
         .shape(Shape::Note)
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("node_shape".to_string()))
+    let g = GraphBuilder::new_named_directed("node_shape")
         .add_node(node)
         .build()
         .unwrap();
@@ -177,10 +177,10 @@ fn builder_support_shape() {
 
 #[test]
 fn single_edge() {
-    let g = GraphBuilder::new_directed(Some("single_edge".to_string()))
-        .add_node(Node::new("N0".to_string()))
-        .add_node(Node::new("N1".to_string()))
-        .add_edge(Edge::new("N0".to_string(), "N1".to_string()))
+    let g = GraphBuilder::new_named_directed("single_edge")
+        .add_node(Node::new("N0"))
+        .add_node(Node::new("N1"))
+        .add_edge(Edge::new("N0", "N1"))
         .build()
         .unwrap();
 
@@ -199,14 +199,14 @@ fn single_edge() {
 
 #[test]
 fn single_edge_with_style() {
-    let edge = EdgeBuilder::new("N0".to_string(), "N1".to_string())
+    let edge = EdgeBuilder::new("N0", "N1")
         .style(EdgeStyle::Bold)
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("single_edge".to_string()))
-        .add_node(Node::new("N0".to_string()))
-        .add_node(Node::new("N1".to_string()))
+    let g = GraphBuilder::new_named_directed("single_edge")
+        .add_node(Node::new("N0"))
+        .add_node(Node::new("N1"))
         .add_edge(edge)
         .build()
         .unwrap();
@@ -226,19 +226,19 @@ fn single_edge_with_style() {
 
 #[test]
 fn edge_statement_port_position() {
-    let node_0 = NodeBuilder::new("N0".to_string())
+    let node_0 = NodeBuilder::new("N0")
         .shape(Shape::Record)
         .label("a|<port0>b")
         .build()
         .unwrap();
 
-    let node_1 = NodeBuilder::new("N1".to_string())
+    let node_1 = NodeBuilder::new("N1")
         .shape(Shape::Record)
         .label("e|<port1>f")
         .build()
         .unwrap();
 
-    let edge = EdgeBuilder::new("N0".to_string(), "N1".to_string())
+    let edge = EdgeBuilder::new("N0", "N1")
         .source_port_position(PortPosition::Port {
             port_name: "port0".to_string(),
             compass_point: Some(CompassPoint::SW),
@@ -250,7 +250,7 @@ fn edge_statement_port_position() {
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("edge_statement_port_position".to_string()))
+    let g = GraphBuilder::new_named_directed("edge_statement_port_position")
         .add_node(node_0)
         .add_node(node_1)
         .add_edge(edge)
@@ -272,19 +272,19 @@ fn edge_statement_port_position() {
 
 #[test]
 fn port_position_attribute() {
-    let node_0 = NodeBuilder::new("N0".to_string())
+    let node_0 = NodeBuilder::new("N0")
         .shape(Shape::Record)
         .label("a|<port0>b")
         .build()
         .unwrap();
 
-    let node_1 = NodeBuilder::new("N1".to_string())
+    let node_1 = NodeBuilder::new("N1")
         .shape(Shape::Record)
         .label("e|<port1>f")
         .build()
         .unwrap();
 
-    let edge = EdgeBuilder::new("N0".to_string(), "N1".to_string())
+    let edge = EdgeBuilder::new("N0", "N1")
         .tail_port(PortPosition::Port {
             port_name: "port0".to_string(),
             compass_point: Some(CompassPoint::SW),
@@ -296,7 +296,7 @@ fn port_position_attribute() {
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("port_position_attribute".to_string()))
+    let g = GraphBuilder::new_named_directed("port_position_attribute")
         .add_node(node_0)
         .add_node(node_1)
         .add_edge(edge)
@@ -318,20 +318,20 @@ fn port_position_attribute() {
 
 #[test]
 fn graph_attributes() {
-    let g = GraphBuilder::new_directed(Some("graph_attributes".to_string()))
+    let g = GraphBuilder::new_named_directed("graph_attributes")
         .add_attribute(
             AttributeType::Graph,
-            "rankdir".to_string(),
+            "rankdir",
             AttributeText::from(RankDir::LeftRight),
         )
         .add_attribute(
             AttributeType::Node,
-            "style".to_string(),
+            "style",
             AttributeText::from(NodeStyle::Filled),
         )
         .add_attribute(
             AttributeType::Edge,
-            "color".to_string(),
+            "color",
             AttributeText::from(Color::Named("red")),
         )
         .build()
@@ -352,7 +352,7 @@ fn graph_attributes() {
 
 #[test]
 fn graph_attributes_extend() {
-    let g = GraphBuilder::new_directed(Some("graph_attributes".to_string()))
+    let g = GraphBuilder::new_named_directed("graph_attributes")
         .extend_with_attributes(
             AttributeType::Graph,
             [(
@@ -411,7 +411,7 @@ fn graph_attributes_statement_builders() {
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("graph_attributes".to_string()))
+    let g = GraphBuilder::new_named_directed("graph_attributes")
         .add_graph_attributes(graph_attributes)
         .add_node_attributes(node_attributes)
         .add_edge_attributes(edge_attributes)
@@ -433,10 +433,10 @@ fn graph_attributes_statement_builders() {
 
 #[test]
 fn clusters() {
-    let cluster_0 = SubGraphBuilder::new(Some("cluster_0".to_string()))
+    let cluster_0 = SubGraphBuilder::new_named("cluster_0")
         .add_graph_attributes(
             GraphAttributeStatementBuilder::new()
-                .label("process #1".to_string())
+                .label("process #1")
                 .style(GraphStyle::Filled)
                 .color(Color::Named("lightgrey"))
                 .build()
@@ -449,16 +449,16 @@ fn clusters() {
                 .build()
                 .unwrap(),
         )
-        .add_edge(Edge::new("a0".to_string(), "a1".to_string()))
-        .add_edge(Edge::new("a1".to_string(), "a2".to_string()))
-        .add_edge(Edge::new("a2".to_string(), "a3".to_string()))
+        .add_edge(Edge::new("a0", "a1"))
+        .add_edge(Edge::new("a1", "a2"))
+        .add_edge(Edge::new("a2", "a3"))
         .build()
         .unwrap();
 
-    let cluster_1 = SubGraphBuilder::new(Some("cluster_1".to_string()))
+    let cluster_1 = SubGraphBuilder::new_named("cluster_1")
         .add_graph_attributes(
             GraphAttributeStatementBuilder::new()
-                .label("process #2".to_string())
+                .label("process #2")
                 .style(GraphStyle::Filled)
                 .color(Color::Named("blue"))
                 .build()
@@ -470,34 +470,34 @@ fn clusters() {
                 .build()
                 .unwrap(),
         )
-        .add_edge(Edge::new("b0".to_string(), "b1".to_string()))
-        .add_edge(Edge::new("b1".to_string(), "b2".to_string()))
-        .add_edge(Edge::new("b2".to_string(), "b3".to_string()))
+        .add_edge(Edge::new("b0", "b1"))
+        .add_edge(Edge::new("b1", "b2"))
+        .add_edge(Edge::new("b2", "b3"))
         .build()
         .unwrap();
 
-    let g = GraphBuilder::new_directed(Some("G".to_string()))
+    let g = GraphBuilder::new_named_directed("G")
         .add_node(
-            NodeBuilder::new("start".to_string())
+            NodeBuilder::new("start")
                 .shape(Shape::Mdiamond)
                 .build()
                 .unwrap(),
         )
         .add_node(
-            NodeBuilder::new("end".to_string())
+            NodeBuilder::new("end")
                 .shape(Shape::Msquare)
                 .build()
                 .unwrap(),
         )
         .add_sub_graph(cluster_0)
         .add_sub_graph(cluster_1)
-        .add_edge(Edge::new("start".to_string(), "a0".to_string()))
-        .add_edge(Edge::new("start".to_string(), "b0".to_string()))
-        .add_edge(Edge::new("a1".to_string(), "b3".to_string()))
-        .add_edge(Edge::new("b2".to_string(), "a3".to_string()))
-        .add_edge(Edge::new("a3".to_string(), "a0".to_string()))
-        .add_edge(Edge::new("a3".to_string(), "end".to_string()))
-        .add_edge(Edge::new("b3".to_string(), "end".to_string()))
+        .add_edge(Edge::new("start", "a0"))
+        .add_edge(Edge::new("start", "b0"))
+        .add_edge(Edge::new("a1", "b3"))
+        .add_edge(Edge::new("b2", "a3"))
+        .add_edge(Edge::new("a3", "a0"))
+        .add_edge(Edge::new("a3", "end"))
+        .add_edge(Edge::new("b3", "end"))
         .build()
         .unwrap();
 
@@ -538,7 +538,7 @@ fn clusters() {
 
 #[test]
 fn edge_validation_error() {
-    let edge_builder = EdgeBuilder::new("N0".to_string(), "N1".to_string())
+    let edge_builder = EdgeBuilder::new("N0", "N1")
         .arrow_size(-1.0)
         .build();
 
@@ -555,7 +555,7 @@ fn edge_validation_error() {
 
 #[test]
 fn edge_build_ignore_validation_error() {
-    let edge = EdgeBuilder::new("N0".to_string(), "N1".to_string())
+    let edge = EdgeBuilder::new("N0", "N1")
         .arrow_size(-1.0)
         .build_ignore_validation();
 
@@ -590,7 +590,7 @@ fn edge_attribute_build_ignore_validation_error() {
 
 #[test]
 fn node_validation_error() {
-    let node_builder = NodeBuilder::new("N0".to_string()).height(0.0).build();
+    let node_builder = NodeBuilder::new("N0").height(0.0).build();
 
     assert!(node_builder.is_err());
 
@@ -605,7 +605,7 @@ fn node_validation_error() {
 
 #[test]
 fn node_build_ignore_validation_error() {
-    let node = NodeBuilder::new("N0".to_string())
+    let node = NodeBuilder::new("N0")
         .height(0.0)
         .build_ignore_validation();