add a test case

Author: imor

src/merge.rs

@@ -1,4 +1,4 @@
-use graphql_parser::query::{Field, Text};
+use graphql_parser::query::{Field, Text, Value};
 use indexmap::IndexMap;
 
 use crate::parser_util::alias_or_name;
@@ -13,6 +13,20 @@ where
         let response_key = alias_or_name(current_field);
         match merged.get_mut(&response_key) {
             Some(existing_field) => {
+                if current_field.name != existing_field.name {
+                    return Err(format!(
+                        "Fields `{}` and `{}` are different",
+                        current_field.name.as_ref(),
+                        existing_field.name.as_ref(),
+                    ));
+                }
+                if !same_arguments(&current_field.arguments, &existing_field.arguments) {
+                    return Err(format!(
+                        "Fields `{}` and `{}` are have different arguments",
+                        current_field.name.as_ref(),
+                        existing_field.name.as_ref(),
+                    ));
+                }
                 existing_field
                     .selection_set
                     .items
@@ -32,3 +46,25 @@ where
 
     Ok(fields)
 }
+
+fn same_arguments<'a, 'b, T>(
+    arguments_a: &[(T::Value, Value<'a, T>)],
+    arguments_b: &[(T::Value, Value<'a, T>)],
+) -> bool
+where
+    T: Text<'a> + Eq + AsRef<str> + Clone,
+{
+    if arguments_a.len() != arguments_b.len() {
+        return false;
+    }
+
+    for (arg_a_name, arg_a_val) in arguments_a {
+        for (arg_b_name, arg_b_val) in arguments_b {
+            if arg_a_name == arg_b_name && arg_a_val != arg_b_val {
+                return false;
+            }
+        }
+    }
+
+    true
+}

test/expected/issue_237_field_merging.out

@@ -0,0 +1,72 @@
+begin;
+    -- https://github.com/supabase/pg_graphql/issues/237
+    create table blog_post(
+        id int primary key,
+        a text,
+        b text,
+        c text,
+        d text,
+        e text,
+        f text
+    );
+    insert into public.blog_post
+    values (1, 'a', 'b', 'c', 'd', 'e', 'f');
+    select jsonb_pretty(
+      graphql.resolve($$
+        query {
+          blogPostCollection {
+            edges {
+              node {
+                a
+                ...c_query
+                ... @include(if: true) {
+                  e
+                }
+              }
+            }
+          }
+          blogPostCollection {
+            edges {
+              node {
+                b
+                ...d_query
+                ... @include(if: true) {
+                  f
+                }
+              }
+            }
+          }
+        }
+
+        fragment c_query on BlogPost {
+          c
+        }
+
+        fragment d_query on BlogPost {
+          d
+        }
+      $$)
+    );
+           jsonb_pretty            
+-----------------------------------
+ {                                +
+     "data": {                    +
+         "blogPostCollection": {  +
+             "edges": [           +
+                 {                +
+                     "node": {    +
+                         "a": "a",+
+                         "b": "b",+
+                         "c": "c",+
+                         "d": "d",+
+                         "e": "e",+
+                         "f": "f" +
+                     }            +
+                 }                +
+             ]                    +
+         }                        +
+     }                            +
+ }
+(1 row)
+
+rollback;

test/sql/issue_237_field_merging.sql

@@ -0,0 +1,50 @@
+begin;
+    -- https://github.com/supabase/pg_graphql/issues/237
+    create table blog_post(
+        id int primary key,
+        a text,
+        b text,
+        c text,
+        d text,
+        e text,
+        f text
+    );
+    insert into public.blog_post
+    values (1, 'a', 'b', 'c', 'd', 'e', 'f');
+    select jsonb_pretty(
+      graphql.resolve($$
+        query {
+          blogPostCollection {
+            edges {
+              node {
+                a
+                ...c_query
+                ... @include(if: true) {
+                  e
+                }
+              }
+            }
+          }
+          blogPostCollection {
+            edges {
+              node {
+                b
+                ...d_query
+                ... @include(if: true) {
+                  f
+                }
+              }
+            }
+          }
+        }
+
+        fragment c_query on BlogPost {
+          c
+        }
+
+        fragment d_query on BlogPost {
+          d
+        }
+      $$)
+    );
+rollback;