Ban println! in code with clippy (#711)

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## Description

A few debug lines slipped in recently, let's make `clippy` `warn` on
those, so they are kicked out by CI. Functional no-op.

V3_GIT_ORIGIN_REV_ID: 290f6de35f9315b68811eb5f15969fb0333e9d06

v3/Cargo.toml

@@ -22,6 +22,9 @@ members = [
 [workspace.lints.clippy]
 all = { level = "warn", priority = -1 }
 pedantic = { level = "warn", priority = -1 }
+# ban printing to stdout and stderr
+print_stdout = "warn"
+print_stderr = "warn"
 # disable certain pedantic warnings
 doc_markdown = "allow"
 implicit_hasher = "allow"

v3/crates/engine/bin/engine/main.rs

@@ -91,6 +91,7 @@ struct EngineState {
 }
 
 #[tokio::main]
+#[allow(clippy::print_stdout)]
 async fn main() {
     let server = ServerOptions::parse();
 
@@ -276,6 +277,7 @@ impl EngineRouter {
     }
 }
 
+#[allow(clippy::print_stdout)]
 async fn start_engine(server: &ServerOptions) -> Result<(), StartupError> {
     let auth_config =
         read_auth_config(&server.authn_config_path).map_err(StartupError::ReadAuth)?;

v3/crates/lang-graphql/benches/schema_serde.rs

@@ -22,6 +22,7 @@ fn generate_schema(type_count: usize) -> String {
     schema_str
 }
 
+#[allow(clippy::print_stdout)]
 pub fn bench_serde(c: &mut Criterion) {
     let mut group = c.benchmark_group("schema_serde");
     for type_count in [100, 1000, 10000] {

v3/crates/lang-graphql/tests/parser_test.rs

@@ -10,6 +10,7 @@ use std::{
 use expect_test::expect_file;
 
 #[cfg(test)]
+#[allow(clippy::print_stdout)]
 fn test_parser_for_schema(schema_path: &Path) -> Result<(), io::Error> {
     let schema = fs::read_to_string(schema_path)?;
     let expected_ast_path = schema_path.with_extension("ast.txt");
@@ -189,6 +190,7 @@ fn project_root() -> PathBuf {
 }
 
 // Additional sanity checks to distinguish our error and success expectations:
+#[allow(clippy::print_stdout)]
 fn assert_is_err<T: std::fmt::Debug>(actual: &parser::Result<T>, path: &Path) {
     if actual.is_ok() {
         println!("erroneously successful parse: {actual:?}");
@@ -199,6 +201,7 @@ fn assert_is_err<T: std::fmt::Debug>(actual: &parser::Result<T>, path: &Path) {
     }
 }
 
+#[allow(clippy::print_stdout)]
 fn assert_is_ok<T: std::fmt::Debug>(actual: &parser::Result<T>, path: &Path) {
     if actual.is_err() {
         println!("error: {actual:?}");

v3/crates/open-dds/src/test_utils.rs

@@ -209,10 +209,11 @@ fn check_titles(schema: &Schema, is_externally_tagged_enum_variant: bool) {
             .as_ref()
             .is_some_and(|metadata| metadata.title.is_some());
 
-        if should_have_title && !has_title {
-            println!("{}", serde_json::to_string_pretty(schema).unwrap());
-            panic!("Schema does not have a title present.")
-        }
+        assert!(
+            !should_have_title || has_title,
+            "Schema does not have a title present: {}",
+            serde_json::to_string_pretty(schema).unwrap()
+        );
     }
 }
 
@@ -232,10 +233,12 @@ fn check_no_arbitrary_additional_properties(schema: &Schema, config: &JsonSchema
                         .contains(&title.as_str())
                 })
             });
-            if has_arbitrary_additional_properties && !is_allowed {
-                println!("{}", serde_json::to_string_pretty(schema).unwrap());
-                panic!("Schema has arbitrary additional properties")
-            }
+
+            assert!(
+                !has_arbitrary_additional_properties || is_allowed,
+                "Schema has arbitrary additional properties: {}",
+                serde_json::to_string_pretty(schema).unwrap()
+            );
         }
     }
 }

v3/crates/query-usage-analytics/src/lib.rs

@@ -107,6 +107,7 @@ mod tests {
 
     #[test]
     // just a dummy serialize test for now to visualize the output
+    #[allow(clippy::print_stdout)]
     fn dummy_serialize() {
         /*
         * Consider we are serializing usage analytics for the following query

v3/crates/schema/bin/build-schema-from-metadata/main.rs

@@ -11,6 +11,7 @@ use std::{
 use hasura_authn_core::Role;
 use schema::{GDSNamespaceGetterAgnostic, GDSRoleNamespaceGetter};
 
+#[allow(clippy::print_stdout)]
 pub fn main() {
     let mut metadata_string = String::new();
     let mut h = stdin();

v3/crates/schema/src/lib.rs

@@ -460,6 +460,7 @@ mod tests {
 
     use crate::{GDSNamespaceGetterAgnostic, GDSRoleNamespaceGetter};
 
+    #[allow(clippy::print_stdout)]
     fn make_sdl_from_metadata_file_for_role(path: &Path, role: &Role) -> String {
         println!("{path:#?}");
         let metadata_string = fs::read_to_string(path).unwrap();
@@ -474,6 +475,7 @@ mod tests {
         })
     }
 
+    #[allow(clippy::print_stdout)]
     fn make_role_agnostic_sdl_from_metadata_file(path: &Path) -> String {
         println!("{path:#?}");
         let metadata_string = fs::read_to_string(path).unwrap();