From 89be091f8756525b53a10f63749eb7ff67b2a36d Mon Sep 17 00:00:00 2001
From: Richard Feldman <oss@rtfeldman.com>
Date: Sat, 18 Nov 2023 21:02:49 -0500
Subject: [PATCH] Order modules in docs sidebar based on `exposes`

---
 crates/compiler/load_internal/src/file.rs   | 16 ++++++++++++++--
 crates/compiler/load_internal/src/module.rs |  2 +-
 crates/docs/src/lib.rs                      |  8 ++++----
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/crates/compiler/load_internal/src/file.rs b/crates/compiler/load_internal/src/file.rs
index 57386b45462..ea2af62253e 100644
--- a/crates/compiler/load_internal/src/file.rs
+++ b/crates/compiler/load_internal/src/file.rs
@@ -3291,7 +3291,7 @@ fn finish(
     exposed_types_storage: ExposedTypesStorageSubs,
     resolved_implementations: ResolvedImplementations,
     dep_idents: IdentIdsByModule,
-    documentation: VecMap<ModuleId, ModuleDocumentation>,
+    mut documentation: VecMap<ModuleId, ModuleDocumentation>,
     abilities_store: AbilitiesStore,
     //
     #[cfg(debug_assertions)] checkmate: Option<roc_checkmate::Collector>,
@@ -3330,6 +3330,18 @@ fn finish(
 
     roc_checkmate::dump_checkmate!(checkmate);
 
+    let mut docs_by_module = Vec::with_capacity(state.exposed_modules.len());
+
+    for module_id in state.exposed_modules.iter() {
+        let docs = documentation.remove(module_id).unwrap_or_else(|| {
+            panic!("A module was exposed but didn't have an entry in `documentation` somehow: {module_id:?}");
+        });
+
+        docs_by_module.push(docs);
+    }
+
+    debug_assert_eq!(documentation.len(), 0);
+
     LoadedModule {
         module_id: state.root_id,
         interns,
@@ -3346,7 +3358,7 @@ fn finish(
         resolved_implementations,
         sources,
         timings: state.timings,
-        docs_by_module: documentation,
+        docs_by_module,
         abilities_store,
     }
 }
diff --git a/crates/compiler/load_internal/src/module.rs b/crates/compiler/load_internal/src/module.rs
index 323456fb5f6..c106c4083c7 100644
--- a/crates/compiler/load_internal/src/module.rs
+++ b/crates/compiler/load_internal/src/module.rs
@@ -43,7 +43,7 @@ pub struct LoadedModule {
     pub resolved_implementations: ResolvedImplementations,
     pub sources: MutMap<ModuleId, (PathBuf, Box<str>)>,
     pub timings: MutMap<ModuleId, ModuleTiming>,
-    pub docs_by_module: VecMap<ModuleId, ModuleDocumentation>,
+    pub docs_by_module: Vec<(ModuleId, ModuleDocumentation)>,
     pub abilities_store: AbilitiesStore,
     pub typechecked: MutMap<ModuleId, CheckedModule>,
 }
diff --git a/crates/docs/src/lib.rs b/crates/docs/src/lib.rs
index 2cd3e7bcca7..faa90e6baa3 100644
--- a/crates/docs/src/lib.rs
+++ b/crates/docs/src/lib.rs
@@ -110,13 +110,13 @@ pub fn generate_docs_html(root_file: PathBuf, build_dir: &Path) {
         .replace("<!-- base -->", &base_url())
         .replace(
             "<!-- Module links -->",
-            render_sidebar(loaded_module.docs_by_module.values()).as_str(),
+            render_sidebar(loaded_module.docs_by_module.iter().map(|(_, docs)| docs)).as_str(),
         );
 
     let all_exposed_symbols = {
         let mut set = VecSet::default();
 
-        for docs in loaded_module.docs_by_module.values() {
+        for (_, docs) in loaded_module.docs_by_module.iter() {
             set.insert_all(docs.exposed_symbols.iter().copied());
         }
 
@@ -146,7 +146,7 @@ pub fn generate_docs_html(root_file: PathBuf, build_dir: &Path) {
     }
 
     // Write each package module's index.html file
-    for module_docs in loaded_module.docs_by_module.values() {
+    for (_, module_docs) in loaded_module.docs_by_module.iter() {
         let module_name = module_docs.name.as_str();
         let module_dir = build_dir.join(module_name.replace('.', "/").as_str());
 
@@ -183,7 +183,7 @@ fn render_package_index(root_module: &LoadedModule) -> String {
     // The list items containing module links
     let mut module_list_buf = String::new();
 
-    for module in root_module.docs_by_module.values() {
+    for (_, module) in root_module.docs_by_module.iter() {
         // The anchor tag containing the module link
         let mut link_buf = String::new();