From 5f2db3ce3da7be4758fc174afd606abab98c7c3a Mon Sep 17 00:00:00 2001
From: ValeriaVG <valeria.viana.gusmao@gmail.com>
Date: Thu, 1 Oct 2020 18:06:18 +0200
Subject: [PATCH 1/3] Validate static schema on load

---
 src/__tests__/usage-test.ts | 13 +++++++++++++
 src/index.ts                |  9 ++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/usage-test.ts b/src/__tests__/usage-test.ts
index d63ee572..d74244b8 100644
--- a/src/__tests__/usage-test.ts
+++ b/src/__tests__/usage-test.ts
@@ -117,4 +117,17 @@ describe('Useful errors when incorrectly used', () => {
       ],
     });
   });
+
+  it('requires a valid schema if static scheme is defined in options', () => {
+    expect(() => {
+      // @ts-expect-error
+      graphqlHTTP({ schema: new GraphQLSchema({ directives: [null] }) });
+    }).to.throw('GraphQL schema validation failed');
+    expect(() => {
+      graphqlHTTP(() => ({
+        // @ts-expect-error
+        schema: new GraphQLSchema({ directives: [null] }),
+      }));
+    }).not.to.throw();
+  });
 });
diff --git a/src/index.ts b/src/index.ts
index 23b4d930..9814fce1 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -190,6 +190,12 @@ export function graphqlHTTP(options: Options): Middleware {
     throw new Error('GraphQL middleware requires options.');
   }
 
+  const staticSchemaValidationErrors =
+    'schema' in options ? validateSchema(options.schema) : undefined;
+
+  if (staticSchemaValidationErrors?.length) {
+    throw Error('GraphQL schema validation failed');
+  }
   return async function graphqlMiddleware(
     request: Request,
     response: Response,
@@ -272,7 +278,8 @@ export function graphqlHTTP(options: Options): Middleware {
       }
 
       // Validate Schema
-      const schemaValidationErrors = validateSchema(schema);
+      const schemaValidationErrors =
+        staticSchemaValidationErrors ?? validateSchema(schema);
       if (schemaValidationErrors.length > 0) {
         // Return 500: Internal Server Error if invalid schema.
         throw httpError(500, 'GraphQL schema validation error.', {

From 080871683c3c5063a2010a1bb383497d236f06c0 Mon Sep 17 00:00:00 2001
From: ValeriaVG <valeria.viana.gusmao@gmail.com>
Date: Thu, 1 Oct 2020 18:07:27 +0200
Subject: [PATCH 2/3] Fix typo in tests

---
 src/__tests__/usage-test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/__tests__/usage-test.ts b/src/__tests__/usage-test.ts
index d74244b8..2f889b32 100644
--- a/src/__tests__/usage-test.ts
+++ b/src/__tests__/usage-test.ts
@@ -118,7 +118,7 @@ describe('Useful errors when incorrectly used', () => {
     });
   });
 
-  it('requires a valid schema if static scheme is defined in options', () => {
+  it('requires a valid schema if static schema is defined in options', () => {
     expect(() => {
       // @ts-expect-error
       graphqlHTTP({ schema: new GraphQLSchema({ directives: [null] }) });

From 284d3ab71bbce1855d0b5f147b0a7ba6141f76d6 Mon Sep 17 00:00:00 2001
From: ValeriaVG <valeria.viana.gusmao@gmail.com>
Date: Thu, 1 Oct 2020 18:41:38 +0200
Subject: [PATCH 3/3] Fix test coverage

---
 src/__tests__/http-test.ts  | 29 +++++++++++++++++++++++++++++
 src/__tests__/usage-test.ts | 14 ++++++++------
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/src/__tests__/http-test.ts b/src/__tests__/http-test.ts
index ffca7714..5098caee 100644
--- a/src/__tests__/http-test.ts
+++ b/src/__tests__/http-test.ts
@@ -248,6 +248,35 @@ function runTests(server: Server) {
       });
     });
 
+    it('Reports validation errors for dynamic schema', async () => {
+      const app = server();
+
+      app.get(
+        urlString(),
+        graphqlHTTP(() => Promise.resolve({ schema: TestSchema })),
+      );
+
+      const response = await app.request().get(
+        urlString({
+          query: '{ test, unknownOne, unknownTwo }',
+        }),
+      );
+
+      expect(response.status).to.equal(400);
+      expect(JSON.parse(response.text)).to.deep.equal({
+        errors: [
+          {
+            message: 'Cannot query field "unknownOne" on type "QueryRoot".',
+            locations: [{ line: 1, column: 9 }],
+          },
+          {
+            message: 'Cannot query field "unknownTwo" on type "QueryRoot".',
+            locations: [{ line: 1, column: 21 }],
+          },
+        ],
+      });
+    });
+
     it('Errors when missing operation name', async () => {
       const app = server();
 
diff --git a/src/__tests__/usage-test.ts b/src/__tests__/usage-test.ts
index 2f889b32..866a8672 100644
--- a/src/__tests__/usage-test.ts
+++ b/src/__tests__/usage-test.ts
@@ -119,15 +119,17 @@ describe('Useful errors when incorrectly used', () => {
   });
 
   it('requires a valid schema if static schema is defined in options', () => {
-    expect(() => {
+    const options = () => ({
       // @ts-expect-error
-      graphqlHTTP({ schema: new GraphQLSchema({ directives: [null] }) });
+      schema: new GraphQLSchema({ directives: [null] }),
+    });
+    const { schema } = options();
+    expect(() => {
+      graphqlHTTP({ schema });
     }).to.throw('GraphQL schema validation failed');
+
     expect(() => {
-      graphqlHTTP(() => ({
-        // @ts-expect-error
-        schema: new GraphQLSchema({ directives: [null] }),
-      }));
+      graphqlHTTP(options);
     }).not.to.throw();
   });
 });