random testing

amqp_codegen/src/random.rs

@@ -0,0 +1,61 @@
+use crate::{snake_case, Amqp};
+use heck::ToUpperCamelCase;
+
+pub(crate) fn codegen_random(amqp: &Amqp) {
+    println!(
+        "#[cfg(test)]
+mod random {{
+use rand::Rng;
+use crate::classes::tests::RandomMethod;
+use super::*;
+"
+    );
+
+    impl_random("Class", || {
+        let class_lens = amqp.classes.len();
+        println!("        match rand::thread_rng().gen_range(0u32..{class_lens}) {{");
+        for (i, class) in amqp.classes.iter().enumerate() {
+            let class_name = class.name.to_upper_camel_case();
+            println!("            {i} => Class::{class_name}({class_name}::random(rng)),");
+        }
+        println!(
+            "            _ => unreachable!(),
+            }}"
+        );
+    });
+
+    for class in &amqp.classes {
+        let class_name = class.name.to_upper_camel_case();
+        impl_random(&class_name, || {
+            let method_len = class.methods.len();
+            println!("        match rand::thread_rng().gen_range(0u32..{method_len}) {{");
+
+            for (i, method) in class.methods.iter().enumerate() {
+                let method_name = method.name.to_upper_camel_case();
+                println!("            {i} => {class_name}::{method_name} {{");
+                for field in &method.fields {
+                    let field_name = snake_case(&field.name);
+                    println!("                {field_name}: RandomMethod::random(rng),");
+                }
+                println!("            }},");
+            }
+            println!(
+                "            _ => unreachable!(),
+            }}"
+            );
+        });
+    }
+
+    println!("}}");
+}
+
+fn impl_random(name: &str, body: impl FnOnce()) {
+    println!(
+        "impl<R: Rng> RandomMethod<R> for {name} {{
+    fn random(rng: &mut R) -> Self {{"
+    );
+
+    body();
+
+    println!("    }}\n}}");
+}