Leverage Itertools::format()

Author: tyranron

juniper/Cargo.toml

@@ -55,6 +55,7 @@ fnv = "1.0.5"
 futures = { version = "0.3.22", features = ["alloc"], default-features = false }
 graphql-parser = { version = "0.4", optional = true }
 indexmap = { version = "2.0", features = ["serde"] }
+itertools = "0.14"
 jiff = { version = "0.2", features = ["std"], default-features = false, optional = true }
 juniper_codegen = { version = "0.16.0", path = "../juniper_codegen" }
 rust_decimal = { version = "1.20", default-features = false, optional = true }

juniper/src/types/utilities.rs

@@ -1,5 +1,7 @@
 use std::collections::HashSet;
 
+use itertools::Itertools as _;
+
 use crate::{
     ast::InputValue,
     schema::{
@@ -179,9 +181,7 @@ where
                         } else {
                             let missing_fields = remaining_required_fields
                                 .into_iter()
-                                .map(|s| format!("\"{s}\""))
-                                .collect::<Vec<_>>()
-                                .join(", ");
+                                .format_with(", ", |s, f| f(&format_args!("\"{s}\"")));
                             Some(error::missing_fields(arg_type, missing_fields))
                         }
                     } else {

juniper/src/validation/context.rs

@@ -3,6 +3,8 @@ use std::{
     fmt::{self, Debug},
 };
 
+use itertools::Itertools as _;
+
 use crate::{
     ast::{Definition, Document},
     schema::model::DynType,
@@ -58,12 +60,7 @@ impl fmt::Display for RuleError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         // This is fine since all `RuleError`s should have at least one source
         // position.
-        let locations = self
-            .locations
-            .iter()
-            .map(ToString::to_string)
-            .collect::<Vec<_>>()
-            .join(", ");
+        let locations = self.locations.iter().format(", ");
         write!(f, "{}. At {locations}", self.message)
     }
 }

juniper/src/validation/rules/overlapping_fields_can_be_merged.rs

@@ -1,6 +1,13 @@
-use std::{borrow::Borrow, cell::RefCell, collections::HashMap, fmt::Debug, hash::Hash};
+use std::{
+    borrow::Borrow,
+    cell::RefCell,
+    collections::HashMap,
+    fmt::{self, Debug},
+    hash::Hash,
+};
 
 use arcstr::ArcStr;
+use itertools::Itertools as _;
 
 use crate::{
     ast::{Arguments, Definition, Document, Field, Fragment, FragmentSpread, Selection, Type},
@@ -745,19 +752,33 @@ fn error_message(reason_name: &str, reason: &ConflictReasonMessage) -> String {
     )
 }
 
-fn format_reason(reason: &ConflictReasonMessage) -> String {
+fn format_reason(reason: &ConflictReasonMessage) -> impl fmt::Display {
+    enum Either<A, B> {
+        A(A),
+        B(B),
+    }
+
+    // TODO: Use `derive_more`.
+    impl<A: fmt::Display, B: fmt::Display> fmt::Display for Either<A, B> {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self {
+                Self::A(a) => write!(f, "{a}"),
+                Self::B(b) => write!(f, "{b}"),
+            }
+        }
+    }
+
     match reason {
-        ConflictReasonMessage::Message(name) => name.clone(),
-        ConflictReasonMessage::Nested(nested) => nested
-            .iter()
-            .map(|ConflictReason(name, subreason)| {
-                format!(
+        ConflictReasonMessage::Message(name) => Either::A(name),
+        ConflictReasonMessage::Nested(nested) => Either::B(nested.iter().format_with(
+            " and ",
+            |ConflictReason(name, subreason), f| {
+                f(&format_args!(
                     r#"subfields "{name}" conflict because {}"#,
                     format_reason(subreason),
-                )
-            })
-            .collect::<Vec<_>>()
-            .join(" and "),
+                ))
+            },
+        )),
     }
 }
 

juniper_warp/Cargo.toml

@@ -46,6 +46,7 @@ headers = "0.3.8"
 async-stream = "0.3"
 env_logger = "0.11"
 futures = "0.3.22"
+itertools = "0.14"
 juniper = { version = "0.16", path = "../juniper", features = ["expose-test-schema"] }
 log = "0.4"
 percent-encoding = "2.1"

juniper_warp/tests/http_test_suite.rs

@@ -1,4 +1,5 @@
 use futures::TryStreamExt as _;
+use itertools::Itertools as _;
 use juniper::{
     EmptyMutation, EmptySubscription, RootNode,
     http::tests::{HttpIntegration, TestResponse, run_http_test_suite},
@@ -69,9 +70,9 @@ impl HttpIntegration for TestWarpIntegration {
 
         let url = Url::parse(&format!("http://localhost:3000{url}")).expect("url to parse");
 
-        let url: String = utf8_percent_encode(url.query().unwrap_or(""), QUERY_ENCODE_SET)
-            .collect::<Vec<_>>()
-            .join("");
+        let url = utf8_percent_encode(url.query().unwrap_or(""), QUERY_ENCODE_SET)
+            .format("")
+            .to_string();
 
         self.make_request(
             warp::test::request()