feat: make admin_fn macro usable outside common_function module (#5850)

* feat: make `admin_fn` macro usable outside common_function module

* chore: expose mod for testing

src/common/function/Cargo.toml

@@ -8,6 +8,7 @@ license.workspace = true
 workspace = true
 
 [features]
+testing = []
 default = ["geo"]
 geo = ["geohash", "h3o", "s2", "wkt", "geo-types", "dep:geo"]
 

src/common/function/src/function.rs

@@ -32,7 +32,7 @@ pub struct FunctionContext {
 
 impl FunctionContext {
     /// Create a mock [`FunctionContext`] for test.
-    #[cfg(test)]
+    #[cfg(any(test, feature = "testing"))]
     pub fn mock() -> Self {
         Self {
             query_ctx: QueryContextBuilder::default().build().into(),

src/common/function/src/state.rs

@@ -28,7 +28,7 @@ pub struct FunctionState {
 
 impl FunctionState {
     /// Create a mock [`FunctionState`] for test.
-    #[cfg(test)]
+    #[cfg(any(test, feature = "testing"))]
     pub fn mock() -> Self {
         use std::sync::Arc;