From c33e9acac270fd15afe99285e50fecd1ca816286 Mon Sep 17 00:00:00 2001
From: Jonathan Wieben <jwieben@hey.com>
Date: Thu, 11 Jul 2024 18:14:45 +0200
Subject: [PATCH] feat(named-operations-object): add option to throw on
 duplicates (#775)

* feat(named-operations-object): add option to throw on duplicate operation name

* add changeset
---
 .changeset/tough-roses-divide.md              |  5 ++
 .../named-operations-object/src/index.ts      | 15 +++++
 .../tests/plugin.spec.ts                      | 56 +++++++++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 .changeset/tough-roses-divide.md

diff --git a/.changeset/tough-roses-divide.md b/.changeset/tough-roses-divide.md
new file mode 100644
index 000000000..4cbf0483e
--- /dev/null
+++ b/.changeset/tough-roses-divide.md
@@ -0,0 +1,5 @@
+---
+'@graphql-codegen/named-operations-object': minor
+---
+
+add option to throw on duplicate operation names
diff --git a/packages/plugins/typescript/named-operations-object/src/index.ts b/packages/plugins/typescript/named-operations-object/src/index.ts
index c8fe40658..400dc1954 100644
--- a/packages/plugins/typescript/named-operations-object/src/index.ts
+++ b/packages/plugins/typescript/named-operations-object/src/index.ts
@@ -24,6 +24,11 @@ export interface NamedOperationsObjectPluginConfig {
    * @default false
    */
   useConsts?: boolean;
+  /**
+   * @description Throws an error if a duplicate operation name is found.
+   * @default false
+   */
+  throwOnDuplicate?: boolean;
 }
 
 export const plugin: PluginFunction<NamedOperationsObjectPluginConfig, string> = (
@@ -43,10 +48,16 @@ export const plugin: PluginFunction<NamedOperationsObjectPluginConfig, string> =
     fragment: new Set(),
   };
 
+  const duplicateOperationNames = [];
+
   oldVisit(allAst, {
     enter: {
       OperationDefinition: node => {
         if (node.name?.value) {
+          if (allOperationsNames[node.operation].has(node.name.value)) {
+            duplicateOperationNames.push(node.name.value);
+            return;
+          }
           allOperationsNames[node.operation].add(node.name.value);
         }
       },
@@ -56,6 +67,10 @@ export const plugin: PluginFunction<NamedOperationsObjectPluginConfig, string> =
     },
   });
 
+  if (config.throwOnDuplicate && duplicateOperationNames.length > 0) {
+    throw new Error(`Duplicated operation name(s): ${duplicateOperationNames.join(', ')}`);
+  }
+
   const objectItems = Object.keys(allOperationsNames)
     .map(operationType => {
       const relevantOperations: Set<string> = allOperationsNames[operationType];
diff --git a/packages/plugins/typescript/named-operations-object/tests/plugin.spec.ts b/packages/plugins/typescript/named-operations-object/tests/plugin.spec.ts
index d2e711e69..82708ffc8 100644
--- a/packages/plugins/typescript/named-operations-object/tests/plugin.spec.ts
+++ b/packages/plugins/typescript/named-operations-object/tests/plugin.spec.ts
@@ -223,4 +223,60 @@ describe('named-operations-object', () => {
       }
     }`);
   });
+
+  it('Should not throw on duplicate operations', async () => {
+    const result = await plugin(
+      null,
+      [
+        {
+          document: parse(/* GraphQL */ `
+            query myQuery {
+              id
+            }
+          `),
+        },
+        {
+          document: parse(/* GraphQL */ `
+            query myQuery {
+              id
+            }
+          `),
+        },
+      ],
+      {},
+    );
+
+    expect(result).toBeSimilarStringTo(`export const namedOperations = {
+      Query: {
+        myQuery: 'myQuery'
+      }
+    }`);
+  });
+
+  it('Should throw on duplicate operations when config.throwOnDuplicate is set', async () => {
+    expect(() =>
+      plugin(
+        null,
+        [
+          {
+            document: parse(/* GraphQL */ `
+              query myQuery {
+                id
+              }
+            `),
+          },
+          {
+            document: parse(/* GraphQL */ `
+              query myQuery {
+                id
+              }
+            `),
+          },
+        ],
+        {
+          throwOnDuplicate: true,
+        },
+      ),
+    ).toThrowErrorMatchingInlineSnapshot(`"Duplicated operation name(s): myQuery"`);
+  });
 });