Put Rust and pgrx tests in separate modules

Since they compile separately, different dependencies can lead to
warnings (see pgcentralfoundation/pgrx#1774 for details). So move shared
functions to a new `test_util` module, keep the Rust-only tests in `mod
test`, and keep the pgrx tests in `mod tests`. I wish I could put the
pgrx tests in the required `pg_test` schema, but it appears that they
require that the module be named "tests".

Thanks @eeeebbbbrrrr for suggesting this solution.

src/lib.rs

@@ -293,34 +293,31 @@ fn validate(id: &str, schemas: &[Value], instance: Value) -> Result<bool, Compil
  }
 }
 
+// Utility functions for the tests and pg_tests modules to use.
 #[cfg(any(test, feature = "pg_test"))]
-#[pg_schema]
-mod tests {
- use super::*;
- use pgrx::pg_sys::panic::CaughtError::PostgresError;
- use pgrx::{spi::SpiError, Json, JsonB};
- use serde_json::json;
- use std::error::Error;
-
- // Enum used to record handling expected errors.
- #[derive(Debug, Eq, PartialEq)]
- enum ErrorCaught {
- True,
- False,
- }
-
+pub mod test_util {
+ use serde_json::Value;
  // Load the user and address schemas (bytes loaded at compile time).
- fn user_schema() -> Value {
+ pub fn user_schema() -> Value {
  let bytes = include_bytes!("../eg/user-profile.schema.json");
  assert!(!bytes.is_empty());
  serde_json::from_slice(bytes).unwrap()
  }
 
- fn addr_schema() -> Value {
+ pub fn addr_schema() -> Value {
  let bytes = include_bytes!("../eg/address.schema.json");
  assert!(!bytes.is_empty());
  serde_json::from_slice(bytes).unwrap()
  }
+}
+
+// Rust-only tests.
+#[cfg(test)]
+mod test {
+ use super::*;
+ use crate::test_util::*;
+ use serde_json::json;
+ use std::error::Error;
 
  // Make sure our Draft enum converts properly into boon's.
  #[test]
@@ -509,6 +506,24 @@ mod tests {
 
  Ok(())
  }
+}
+
+// pgrx tests.
+#[cfg(any(test, feature = "pg_test"))]
+#[pg_schema]
+mod tests {
+ use super::*;
+ use crate::test_util::*;
+ use pgrx::pg_sys::panic::CaughtError::PostgresError;
+ use pgrx::{spi::SpiError, Json, JsonB};
+ use serde_json::json;
+
+ // Enum used to record handling expected errors.
+ #[derive(Debug, Eq, PartialEq)]
+ enum ErrorCaught {
+ True,
+ False,
+ }
 
  #[pg_test]
  fn test_jsonschema_is_valid() {