fix(coerce-input-value): input object coercion rejects arrays

src/utilities/__tests__/coerceInputValue-test.ts

@@ -183,11 +183,19 @@ describe('coerceInputValue', () => {
   });
 
   describe('for GraphQLInputObject', () => {
+    const DeepObject = new GraphQLInputObjectType({
+      name: 'DeepObject',
+      fields: {
+        foo: { type: new GraphQLNonNull(GraphQLInt) },
+        bar: { type: GraphQLInt },
+      },
+    });
     const TestInputObject = new GraphQLInputObjectType({
       name: 'TestInputObject',
       fields: {
         foo: { type: new GraphQLNonNull(GraphQLInt) },
         bar: { type: GraphQLInt },
+        deepObject: { type: DeepObject },
       },
     });
 
@@ -271,6 +279,31 @@ describe('coerceInputValue', () => {
         },
       ]);
     });
+
+    it('returns an error for an array type', () => {
+      const result = coerceValue([{ foo: 1 }, { bar: 1 }], TestInputObject);
+      expectErrors(result).to.deep.equal([
+        {
+          error: 'Expected type "TestInputObject" to be an object.',
+          path: [],
+          value: [{ foo: 1 }, { bar: 1 }],
+        },
+      ]);
+    });
+
+    it('returns an error for an array type on a nested field', () => {
+      const result = coerceValue(
+        { foo: 1, deepObject: [1, 2, 3] },
+        TestInputObject,
+      );
+      expectErrors(result).to.deep.equal([
+        {
+          error: 'Expected type "DeepObject" to be an object.',
+          path: ['deepObject'],
+          value: [1, 2, 3],
+        },
+      ]);
+    });
   });
 
   describe('for GraphQLInputObject that isOneOf', () => {

src/utilities/coerceInputValue.ts

@@ -86,7 +86,7 @@ function coerceInputValueImpl(
   }
 
   if (isInputObjectType(type)) {
-    if (!isObjectLike(inputValue)) {
+    if (!isObjectLike(inputValue) || Array.isArray(inputValue)) {
       onError(
         pathToArray(path),
         inputValue,