From ae1aa6540761e54a76b8f7984cf93cd3a0d011d0 Mon Sep 17 00:00:00 2001
From: nsfisis <nsfisis@gmail.com>
Date: Sun, 3 May 2026 11:55:03 +0900
Subject: refactor: switch internal maps/sets from HashMap to IndexMap

Adopt indexmap workspace-wide so iteration order is deterministic and
follows insertion order. The non-deterministic order of std HashMap
otherwise leaks into resolver decisions when multiple valid solutions
exist (e.g. cyclic require pairs under prefer-lowest), making behavior
flaky and divergent from Composer's PHP-array semantics.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 crates/mozart-vcs/src/driver/git.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

(limited to 'crates/mozart-vcs/src/driver/git.rs')

diff --git a/crates/mozart-vcs/src/driver/git.rs b/crates/mozart-vcs/src/driver/git.rs
index cc9a210..43f4ecb 100644
--- a/crates/mozart-vcs/src/driver/git.rs
+++ b/crates/mozart-vcs/src/driver/git.rs
@@ -1,4 +1,5 @@
-use std::collections::{BTreeMap, HashMap};
+use indexmap::IndexMap;
+use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
 
 use anyhow::Result;
@@ -17,7 +18,7 @@ pub struct GitDriver {
     root_identifier: Option<String>,
     tags: Option<BTreeMap<String, String>>,
     branches: Option<BTreeMap<String, String>>,
-    info_cache: HashMap<String, Option<serde_json::Value>>,
+    info_cache: IndexMap<String, Option<serde_json::Value>>,
     git_util: GitUtil,
     is_local: bool,
 }
@@ -37,7 +38,7 @@ impl GitDriver {
             root_identifier: None,
             tags: None,
             branches: None,
-            info_cache: HashMap::new(),
+            info_cache: IndexMap::new(),
             git_util,
             is_local,
         }
@@ -85,7 +86,7 @@ impl GitDriver {
     fn parse_tags(output: &str) -> BTreeMap<String, String> {
         let mut tags = BTreeMap::new();
         // First pass: collect dereferenced tags (^{})
-        let mut dereferenced = HashMap::new();
+        let mut dereferenced = IndexMap::new();
         for line in output.lines() {
             let line = line.trim();
             if line.is_empty() {
-- 
cgit v1.3.1