Make sure that imports are always in the same order between runs. This

makes the output more stable for putting it into a versioning system
like git

libjrpc/src/ir.rs

@@ -1,5 +1,5 @@
 use std::{
-    collections::{HashMap, HashSet},
+    collections::{BTreeMap, BTreeSet},
     error::Error,
     fmt::{Debug, Display},
     hash::{Hash, Hasher},
@@ -20,7 +20,7 @@ pub trait Definition: Debug {
 
 #[derive(Debug, Clone)]
 pub struct IR {
-    pub options: HashMap<String, String>,
+    pub options: BTreeMap<String, String>,
     pub steps: Vec<Step>,
 }
 
@@ -58,7 +58,12 @@ impl ToString for BaseType {
 
 impl Hash for BaseType {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        self.to_string().hash(state);
+        // Hash the enum variant itself
+        std::mem::discriminant(self).hash(state);
+        // If the variant has data, hash that too
+        if let BaseType::Custom(name) = self {
+            name.hash(state);
+        }
     }
 }
 
@@ -178,7 +183,7 @@ impl Type {
 #[derive(Debug, Clone)]
 pub struct TypeDefinition {
     pub name: String,
-    pub depends: HashSet<BaseType>,
+    pub depends: BTreeSet<BaseType>,
     pub fields: Vec<Field>,
     pub position: ParserPosition,
 }
@@ -223,7 +228,7 @@ pub struct EnumField {
 #[derive(Debug, Clone)]
 pub struct ServiceDefinition {
     pub name: String,
-    pub depends: HashSet<BaseType>,
+    pub depends: BTreeSet<BaseType>,
     pub methods: Vec<Method>,
     pub position: ParserPosition,
 }
@@ -259,7 +264,7 @@ pub struct MethodOutput {
 #[derive(Debug, Clone)]
 pub struct MethodDecorators {
     pub description: Option<String>,
-    pub parameter_descriptions: HashMap<String, String>,
+    pub parameter_descriptions: BTreeMap<String, String>,
     pub return_description: Option<String>,
 }
 
@@ -267,7 +272,7 @@ fn build_type(stmt: &TypeStatement) -> Result<TypeDefinition> {
     let mut typedef = TypeDefinition {
         position: stmt.position.clone(),
         name: stmt.name.clone(),
-        depends: HashSet::new(),
+        depends: BTreeSet::new(),
         fields: Vec::new(),
     };
 
@@ -332,7 +337,7 @@ fn build_service(stmt: &ServiceStatement) -> Result<ServiceDefinition> {
     let mut servdef = ServiceDefinition {
         position: stmt.position.clone(),
         name: stmt.name.clone(),
-        depends: HashSet::new(),
+        depends: BTreeSet::new(),
         methods: Vec::new(),
     };
 
@@ -349,7 +354,7 @@ fn build_service(stmt: &ServiceStatement) -> Result<ServiceDefinition> {
             }),
             decorators: MethodDecorators {
                 description: None,
-                parameter_descriptions: HashMap::new(),
+                parameter_descriptions: BTreeMap::new(),
                 return_description: None,
             },
         };
@@ -450,7 +455,7 @@ fn build_service(stmt: &ServiceStatement) -> Result<ServiceDefinition> {
 }
 
 pub fn build_ir(root: &Vec<RootNode>) -> Result<IR> {
-    let mut options = HashMap::<String, String>::new();
+    let mut options = BTreeMap::<String, String>::new();
     let mut steps = Vec::new();
 
     for node in root {
@@ -476,8 +481,8 @@ pub fn build_ir(root: &Vec<RootNode>) -> Result<IR> {
         }
     }
 
-    let mut all_types = HashSet::<String>::new();
-    let mut serv_types = HashSet::<String>::new();
+    let mut all_types = BTreeSet::<String>::new();
+    let mut serv_types = BTreeSet::<String>::new();
 
     for bi in &BUILT_INS {
         all_types.insert(bi.to_string());
@@ -577,3 +582,36 @@ impl Display for IRError {
         write!(f, "ParserError: {} at {:?}", self.message, self.position)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn btreeset_order_is_consistent() {
+        let mut set1 = BTreeSet::new();
+        let mut set2 = BTreeSet::new();
+
+        let elements = vec![
+            BaseType::Custom("CustomType".to_string()),
+            BaseType::Void,
+            BaseType::Bytes,
+            BaseType::Float,
+        ];
+
+        // Insert in normal order
+        for elem in &elements {
+            set1.insert(elem.clone());
+        }
+
+        // Insert in reverse order
+        for elem in elements.iter().rev() {
+            set2.insert(elem.clone());
+        }
+
+        let iter1: Vec<_> = set1.iter().cloned().collect();
+        let iter2: Vec<_> = set2.iter().cloned().collect();
+
+        assert_eq!(iter1, iter2); // Order must be the same
+    }
+}