test: tests to show predicate simplification on chunks (#3649)

* test: tests to show predicate simplification on chunks

* fix: clippy

* refactor: less Box

* refactor: make typealias + add comments, hopefully to improve clarity

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

query/src/frontend/influxrpc.rs

@@ -1953,7 +1953,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_rewrite_table_names() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             InfluxRpcPlanner::new()
                 .table_names(test_db, rpc_predicate)
                 .expect("creating plan");
@@ -1963,7 +1963,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_rewrite_tag_keys() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             InfluxRpcPlanner::new()
                 .tag_keys(test_db, rpc_predicate)
                 .expect("creating plan");
@@ -1973,7 +1973,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_rewrite_tag_values() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             InfluxRpcPlanner::new()
                 .tag_values(test_db, "foo", rpc_predicate)
                 .expect("creating plan");
@@ -1983,7 +1983,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_rewrite_field_columns() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             InfluxRpcPlanner::new()
                 .field_columns(test_db, rpc_predicate)
                 .expect("creating plan");
@@ -1993,7 +1993,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_rewrite_read_filter() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             InfluxRpcPlanner::new()
                 .read_filter(test_db, rpc_predicate)
                 .expect("creating plan");
@@ -2003,7 +2003,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_read_group() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             let agg = Aggregate::None;
             let group_columns = &["foo"];
             InfluxRpcPlanner::new()
@@ -2015,7 +2015,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_predicate_read_window_aggregate() {
-        run_test::<_, TestDatabase>(|test_db, rpc_predicate| {
+        run_test(&|test_db, rpc_predicate| {
             let agg = Aggregate::First;
             let every = WindowDuration::from_months(1, false);
             let offset = WindowDuration::from_months(1, false);
@@ -2026,17 +2026,15 @@ mod tests {
         .await
     }
 
-    /// Runs func() and checks that predicates are simplified prior to sending them off
+    /// Given a `TestDatabase` plans a InfluxRPC query
-    async fn run_test<F, D>(f: F)
+    /// (e.g. read_filter, read_window_aggregate, etc). The test below
-    where
+    /// ensures that predicates are simplified during query planning.
-        F: FnOnce(&TestDatabase, InfluxRpcPredicate) + Send,
+    type PlanRPCFunc = dyn Fn(&TestDatabase, InfluxRpcPredicate) + Send + Sync;
-    {
+
-        let chunk0 = Arc::new(
+    /// Runs func() and checks that predicates are simplified prior to
-            TestChunk::new("h2o")
+    /// sending them down to the chunks for processing.
-                .with_id(0)
+    async fn run_test(func: &'static PlanRPCFunc) {
-                .with_tag_column("foo")
+        // ------------- Test 1 ----------------
-                .with_time_column(),
-        );
 
         // this is what happens with a grpc predicate on a tag
         //
@@ -2053,22 +2051,74 @@ mod tests {
             .add_expr(expr.eq(lit("bar")))
             .build();
 
+        // verify that the predicate was rewritten to `foo = 'bar'`
+        let expr = col("foo").eq(lit("bar"));
+        let expected_predicate = PredicateBuilder::new().add_expr(expr).build();
+
+        run_test_with_predicate(&func, silly_predicate, expected_predicate).await;
+
+        // ------------- Test 2 ----------------
+        // Validate that _measurement predicates are translated
+        //
+        // https://github.com/influxdata/influxdb_iox/issues/3601
+        // _measurement = 'foo'
+        let silly_predicate = PredicateBuilder::new()
+            .add_expr(col("_measurement").eq(lit("foo")))
+            .build();
+
+        // verify that the predicate was rewritten to `false` as the
+        // measurement name is `h20`
+        let expr = lit(false);
+
+        let expected_predicate = PredicateBuilder::new().add_expr(expr).build();
+        run_test_with_predicate(&func, silly_predicate, expected_predicate).await;
+
+        // ------------- Test 3 ----------------
+        // more complicated _measurement predicates are translated
+        //
+        // https://github.com/influxdata/influxdb_iox/issues/3601
+        // (_measurement = 'foo' or measurement = 'h2o') AND time > 5
+        let silly_predicate = PredicateBuilder::new()
+            .add_expr(
+                col("_measurement")
+                    .eq(lit("foo"))
+                    .or(col("_measurement").eq(lit("h2o")))
+                    .and(col("time").gt(lit(5))),
+            )
+            .build();
+
+        // verify that the predicate was rewritten to time > 5
+        let expr = col("time").gt(lit(5));
+
+        let expected_predicate = PredicateBuilder::new().add_expr(expr).build();
+        run_test_with_predicate(&func, silly_predicate, expected_predicate).await;
+    }
+
+    /// Runs func() with the specified predicate and verifies
+    /// `expected_predicate` is received by the chunk
+    async fn run_test_with_predicate(
+        func: &PlanRPCFunc,
+        predicate: Predicate,
+        expected_predicate: Predicate,
+    ) {
+        let chunk0 = Arc::new(
+            TestChunk::new("h2o")
+                .with_id(0)
+                .with_tag_column("foo")
+                .with_time_column(),
+        );
+
         let executor = Arc::new(Executor::new(1));
         let test_db = TestDatabase::new(Arc::clone(&executor));
         test_db.add_chunk("my_partition_key", Arc::clone(&chunk0));
 
-        let rpc_predicate = InfluxRpcPredicate::new(None, silly_predicate);
+        let rpc_predicate = InfluxRpcPredicate::new(None, predicate);
 
         // run the function
-        f(&test_db, rpc_predicate);
+        func(&test_db, rpc_predicate);
 
         let actual_predicate = test_db.get_chunks_predicate();
 
-        // verify that the predicate was rewritten to `foo = 'bar'`
-        let expr = col("foo").eq(lit("bar"));
-
-        let expected_predicate = PredicateBuilder::new().add_expr(expr).build();
-
         assert_eq!(
             actual_predicate, expected_predicate,
             "\nActual: {:?}\nExpected: {:?}",