fix: handle undefined args (#223)

fixes #224

Author: simonfaltum

lib/query-validation-visitor.js

@@ -115,7 +115,7 @@ module.exports = class QueryValidationVisitor {
   onArgumentEnter (arg) {
     const argName = arg.name.value
     // look for directive and validate argument if directive found
-    const argTypeDef = this.currentrFieldDef.args.find(d => d.name === argName)
+    const argTypeDef = this.currentrFieldDef?.args.find(d => d.name === argName)
 
     if (!argTypeDef) return
 

test/foreign-query-directives.test.js

@@ -0,0 +1,51 @@
+const { deepStrictEqual, strictEqual } = require('assert')
+
+module.exports.test = function (setup, implType) {
+  describe('Directive Argument Handling', function () {
+    before(async function () {
+      this.typeDefs = `
+        directive @component(name: String!) on QUERY | MUTATION | SUBSCRIPTION
+
+        type Query {
+          getUsers: [User]
+        }
+
+        type User {
+          id: ID
+          name: String
+          email: String
+        }
+      `
+
+      this.request = await setup({ typeDefs: this.typeDefs })
+    })
+
+    it("should not throw \"Cannot read properties of undefined (reading 'args')\" error when querying", async function () {
+      const query = `
+        query GetCurrentUser @component(name: "exampleComponent") {
+          getUsers {
+            id
+            name
+            email
+          }
+        }
+      `
+      const { body, statusCode } = await this.request
+        .post('/graphql')
+        .set('Accept', 'application/json')
+        .send({ query })
+
+      // Check for successful execution and no errors in the response
+      strictEqual(
+        statusCode,
+        200,
+        'Expected HTTP status code 200 for successful GraphQL query execution.'
+      )
+      deepStrictEqual(
+        body.errors,
+        undefined,
+        'Expected no errors in the GraphQL response.'
+      )
+    })
+  })
+}

test/testsuite-apollo-plugin.js

@@ -18,4 +18,5 @@ describe('Server validator based implementation - Apollo plugin', function () {
   require('./string.test').test(setup, IMPL_TYPE)
   require('./argument-dynamic.test').test(setup, IMPL_TYPE)
   require('./union.test').test(setup, IMPL_TYPE)
+  require('./foreign-query-directives.test').test(setup, IMPL_TYPE)
 })