Get QUERY_BATCH_SIZE at compile time

query-engine/connectors/sql-query-connector/src/context.rs

@@ -33,18 +33,29 @@ impl<'a> Context<'a> {
     }
 }
 
+/// Overrides the default number of allowed elements in query's `IN` or `NOT IN`
+/// statement for the currently loaded connector.
+/// Certain databases error out if querying with too many items. For test
+/// purposes, this value can be set with the `QUERY_BATCH_SIZE` environment
+/// value to a smaller number.
+#[cfg(not(target_arch = "wasm32"))]
 fn get_batch_size(default: usize) -> Option<usize> {
     use once_cell::sync::Lazy;
 
-    /// Overrides the default number of allowed elements in query's `IN` or `NOT IN`
-    /// statement for the currently loaded connector.
-    /// Certain databases error out if querying with too many items. For test
-    /// purposes, this value can be set with the `QUERY_BATCH_SIZE` environment
-    /// value to a smaller number.
     static BATCH_SIZE_OVERRIDE: Lazy<Option<usize>> = Lazy::new(|| {
         std::env::var("QUERY_BATCH_SIZE")
             .ok()
             .map(|size| size.parse().expect("QUERY_BATCH_SIZE: not a valid size"))
     });
+
     (*BATCH_SIZE_OVERRIDE).or(Some(default))
 }
+
+/// In WASM there's no runtime environment, so we can't read the QUERY_BATCH_SIZE var at runtime.
+/// In tests however we depend on that var being set, but we can get away with a build-time override
+#[cfg(target_arch = "wasm32")]
+fn get_batch_size(default: usize) -> Option<usize> {
+    option_env!("QUERY_BATCH_SIZE")
+        .map(|size| size.parse().expect("QUERY_BATCH_SIZE: not a valid size"))
+        .or(Some(default))
+}