Generate Graphviz dots

src/lib.rs

@@ -46,6 +46,24 @@ pub enum NodeType {
     Integer,
 }
 
+impl NodeType {
+    pub fn can_have_children(&self) -> bool {
+        matches!(self, NodeType::Object { .. } | NodeType::Array { .. })
+    }
+
+    pub fn symbol(&self) -> &'static str {
+        match self {
+            NodeType::Null => "NULL",
+            NodeType::Boolean => "Bool",
+            NodeType::Array { .. } => "[]",
+            NodeType::Object { .. } => "{}",
+            NodeType::String => "str",
+            NodeType::Number => "num",
+            NodeType::Integer => "int",
+        }
+    }
+}
+
 #[derive(Debug, Clone, serde::Serialize)]
 pub struct TreeNode {
     pub name: String,
@@ -60,6 +78,10 @@ pub struct TreeNode {
 }
 
 impl TreeNode {
+    pub fn print_name(&self) -> String {
+        format!("{} {}", self.name, self.r#type.symbol())
+    }
+
     /// Merge two TreeNode
     pub fn merge_with(self, other: Self) -> Self {
         if !matches!(self.r#type, NodeType::String | NodeType::Object { .. }) {

src/main.rs

@@ -1,5 +1,6 @@
 use clap::{Parser, Subcommand};
-use openapi_parser::{build_tree, parse_schema};
+use openapi_parser::{build_tree, parse_schema, NodeType, TreeNode};
+use std::fmt::Write;
 
 /// Dump the tree structure of a schema element as dot file
 #[derive(Parser, Debug)]
@@ -25,6 +26,9 @@ struct Args {
 enum Action {
     /// Dump as JSON
     Json,
+
+    /// Dump as Graphviz graph
+    Graph,
 }
 
 fn main() {
@@ -42,5 +46,34 @@ fn main() {
 
     match args.action {
         Action::Json => println!("{}", serde_json::to_string(&tree).unwrap()),
+        Action::Graph => println!("{}", graphviz_export(&tree)),
     }
 }
+
+fn recurse_export(node: &TreeNode, parent_name: &str, out: &mut String) {
+    if !parent_name.is_empty() && node.r#type.can_have_children() {
+        writeln!(out, "\"{}\" -> \"{}\";", parent_name, node.print_name()).unwrap();
+    }
+
+    match &node.r#type {
+        NodeType::Array { item } => {
+            recurse_export(item, &node.print_name(), out);
+        }
+        NodeType::Object { children, .. } => {
+            for child in children {
+                recurse_export(child, &node.print_name(), out);
+            }
+        }
+
+        _ => {}
+    }
+}
+
+fn graphviz_export(tree: &TreeNode) -> String {
+    let mut out = "digraph G {\n".to_string();
+
+    recurse_export(tree, "", &mut out);
+
+    out.push_str("}\n");
+    out
+}