Add API to opt out of case conversion

crates/bindings/src/lib.rs

@@ -36,6 +36,7 @@ pub use sats::SpacetimeType;
 pub use spacetimedb_bindings_macro::__TableHelper;
 pub use spacetimedb_bindings_sys as sys;
 pub use spacetimedb_lib;
+pub use spacetimedb_lib::db::raw_def::v10::CaseConversionPolicy;
 pub use spacetimedb_lib::de::{Deserialize, DeserializeOwned};
 pub use spacetimedb_lib::sats;
 pub use spacetimedb_lib::ser::Serialize;

crates/bindings/src/rt.rs

@@ -4,7 +4,9 @@ use crate::query_builder::{FromWhere, HasCols, LeftSemiJoin, RawQuery, RightSemi
 use crate::table::IndexAlgo;
 use crate::{sys, AnonymousViewContext, IterBuf, ReducerContext, ReducerResult, SpacetimeType, Table, ViewContext};
 use spacetimedb_lib::bsatn::EncodeError;
-use spacetimedb_lib::db::raw_def::v10::{ExplicitNames as RawExplicitNames, RawModuleDefV10Builder};
+use spacetimedb_lib::db::raw_def::v10::{
+    CaseConversionPolicy, ExplicitNames as RawExplicitNames, RawModuleDefV10Builder,
+};
 pub use spacetimedb_lib::db::raw_def::v9::Lifecycle as LifecycleReducer;
 use spacetimedb_lib::db::raw_def::v9::{RawIndexAlgorithm, TableType, ViewResultHeader};
 use spacetimedb_lib::de::{self, Deserialize, DeserializeOwned, Error as _, SeqProductAccess};
@@ -856,6 +858,28 @@ pub fn register_row_level_security(sql: &'static str) {
     })
 }
 
+/// Set the case conversion policy for this module.
+///
+/// This is an internal API for modules that need to opt out of the default
+/// `SnakeCase` case conversion (e.g. controldb which has existing data).
+///
+/// # Usage
+///
+/// ```ignore
+/// #[export_name = "__preinit__10_no_case_conversion"]
+/// extern "C" fn no_case_conversion() {
+///     spacetimedb::rt::register_case_conversion_policy(
+///         spacetimedb::rt::CaseConversionPolicy::None,
+///     );
+/// }
+/// ```
+#[doc(hidden)]
+pub fn register_case_conversion_policy(policy: CaseConversionPolicy) {
+    register_describer(move |module| {
+        module.inner.set_case_conversion_policy(policy);
+    })
+}
+
 /// A builder for a module.
 #[derive(Default)]
 pub struct ModuleBuilder {

crates/lib/src/db/raw_def/v10.rs

@@ -1054,6 +1054,22 @@ impl RawModuleDefV10Builder {
         self.explicit_names_mut().merge(names);
     }
 
+    /// Set the case conversion policy for this module.
+    ///
+    /// By default, SpacetimeDB applies `SnakeCase` conversion to table names,
+    /// column names, reducer names, etc. Use `CaseConversionPolicy::None` to
+    /// disable all case conversion (useful for modules with existing data that
+    /// was stored under the original naming convention).
+    pub fn set_case_conversion_policy(&mut self, policy: CaseConversionPolicy) {
+        // Remove any existing policy section.
+        self.module
+            .sections
+            .retain(|s| !matches!(s, RawModuleDefV10Section::CaseConversionPolicy(_)));
+        self.module
+            .sections
+            .push(RawModuleDefV10Section::CaseConversionPolicy(policy));
+    }
+
     /// Finish building, consuming the builder and returning the module.
     /// The module should be validated before use.
     pub fn finish(self) -> RawModuleDefV10 {