From e1e6e386e8866eebbf3cffcfb1c385b097b45fa1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fausto=20N=C3=BA=C3=B1ez=20Alberro?=
 <fausto.nunez@mailbox.org>
Date: Sun, 31 Mar 2019 14:10:00 +0200
Subject: [PATCH 1/2] codegen: improve "could not find field" error message

---
 graphql_client_codegen/src/shared.rs | 31 +++++++++++++++++++---------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/graphql_client_codegen/src/shared.rs b/graphql_client_codegen/src/shared.rs
index bc3c9e1c1..94c092baf 100644
--- a/graphql_client_codegen/src/shared.rs
+++ b/graphql_client_codegen/src/shared.rs
@@ -6,6 +6,19 @@ use proc_macro2::{Ident, Span, TokenStream};
 use query::QueryContext;
 use selection::*;
 
+fn format_available_fields(fields: &[GqlObjectField]) -> String {
+    fields
+        .iter()
+        .map(|ref field| &field.name)
+        .fold(String::new(), |mut acc, item| {
+            acc.push_str(item);
+            acc.push_str(", ");
+            acc
+        })
+        .trim_end_matches(", ")
+        .to_owned()
+}
+
 pub(crate) fn render_object_field(
     field_name: &str,
     field_type: &TokenStream,
@@ -77,7 +90,13 @@ pub(crate) fn field_impls_for_selection(
                 let ty = fields
                     .iter()
                     .find(|f| &f.name == name)
-                    .ok_or_else(|| format_err!("could not find field `{}`", name))?
+                    .ok_or_else(|| {
+                        format_err!(
+                            "Could not find field `{}`. Available fields: `{}`.",
+                            name,
+                            format_available_fields(fields).as_str()
+                        )
+                    })?
                     .type_
                     .inner_name_str();
                 let prefix = format!("{}{}", prefix.to_camel_case(), alias.to_camel_case());
@@ -111,15 +130,7 @@ pub(crate) fn response_fields_for_selection(
                             "Could not find field `{}` on `{}`. Available fields: `{}`.",
                             *name,
                             type_name,
-                            schema_fields
-                                .iter()
-                                .map(|ref field| &field.name)
-                                .fold(String::new(), |mut acc, item| {
-                                    acc.push_str(item);
-                                    acc.push_str(", ");
-                                    acc
-                                })
-                                .trim_end_matches(", ")
+                            format_available_fields(schema_fields).as_str()
                         )
                     })?;
                 let ty = schema_field.type_.to_rust(

From 4523edea9f62de0fc4968b8a9bfa9ed21810534a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fausto=20N=C3=BA=C3=B1ez=20Alberro?=
 <fausto.nunez@mailbox.org>
Date: Tue, 2 Apr 2019 23:08:06 +0200
Subject: [PATCH 2/2] to be squashed: use itertools for formatting

---
 graphql_client_codegen/Cargo.toml    |  1 +
 graphql_client_codegen/src/lib.rs    |  1 +
 graphql_client_codegen/src/shared.rs | 16 ++++------------
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/graphql_client_codegen/Cargo.toml b/graphql_client_codegen/Cargo.toml
index f3beb5626..9020335d7 100644
--- a/graphql_client_codegen/Cargo.toml
+++ b/graphql_client_codegen/Cargo.toml
@@ -8,6 +8,7 @@ repository = "https://github.com/graphql-rust/graphql-client"
 
 [dependencies]
 failure = "0.1"
+itertools = "0.8"
 lazy_static = "1.0"
 quote = "0.6"
 syn = "0.15.20"
diff --git a/graphql_client_codegen/src/lib.rs b/graphql_client_codegen/src/lib.rs
index 7d42e88ea..0f1e5e5ba 100644
--- a/graphql_client_codegen/src/lib.rs
+++ b/graphql_client_codegen/src/lib.rs
@@ -9,6 +9,7 @@
 extern crate failure;
 extern crate graphql_parser;
 extern crate heck;
+extern crate itertools;
 #[macro_use]
 extern crate lazy_static;
 extern crate proc_macro;
diff --git a/graphql_client_codegen/src/shared.rs b/graphql_client_codegen/src/shared.rs
index 94c092baf..beb896032 100644
--- a/graphql_client_codegen/src/shared.rs
+++ b/graphql_client_codegen/src/shared.rs
@@ -5,18 +5,10 @@ use objects::GqlObjectField;
 use proc_macro2::{Ident, Span, TokenStream};
 use query::QueryContext;
 use selection::*;
+use itertools::Itertools;
 
 fn format_available_fields(fields: &[GqlObjectField]) -> String {
-    fields
-        .iter()
-        .map(|ref field| &field.name)
-        .fold(String::new(), |mut acc, item| {
-            acc.push_str(item);
-            acc.push_str(", ");
-            acc
-        })
-        .trim_end_matches(", ")
-        .to_owned()
+    fields.iter().map(|ref field| &field.name).format("`, `").to_string()
 }
 
 pub(crate) fn render_object_field(
@@ -94,7 +86,7 @@ pub(crate) fn field_impls_for_selection(
                         format_err!(
                             "Could not find field `{}`. Available fields: `{}`.",
                             name,
-                            format_available_fields(fields).as_str()
+                            format_available_fields(fields)
                         )
                     })?
                     .type_
@@ -130,7 +122,7 @@ pub(crate) fn response_fields_for_selection(
                             "Could not find field `{}` on `{}`. Available fields: `{}`.",
                             *name,
                             type_name,
-                            format_available_fields(schema_fields).as_str()
+                            format_available_fields(schema_fields)
                         )
                     })?;
                 let ty = schema_field.type_.to_rust(