Improve coverage of the entire codebase

src/__fixtures__/schema-kitchen-sink.graphql

@@ -130,6 +130,7 @@ extend input InputType @onInputObject
 This is a description of the `@skip` directive
 """
 directive @skip(
+  """This is a description of the `if` argument"""
   if: Boolean! @onArgumentDefinition
 ) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 

src/__tests__/graphql-test.js

@@ -0,0 +1,18 @@
+// @flow strict
+
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+
+import { GraphQLSchema } from '../type/schema';
+
+import { graphqlSync } from '../graphql';
+
+describe('graphql', () => {
+  it('report errors raised during schema validation', () => {
+    const schema = new GraphQLSchema({});
+    const result = graphqlSync({ schema, source: '{ __typename }' });
+    expect(result).to.deep.equal({
+      errors: [{ message: 'Query root type must be provided.' }],
+    });
+  });
+});

src/__tests__/starWarsQuery-test.js

@@ -3,7 +3,7 @@
 import { expect } from 'chai';
 import { describe, it } from 'mocha';
 
-import { graphql } from '../graphql';
+import { graphql, graphqlSync } from '../graphql';
 
 import { StarWarsSchema as schema } from './starWarsSchema';
 
@@ -45,6 +45,9 @@ describe('Star Wars Query Tests', () => {
           },
         },
       });
+
+      const syncResult = graphqlSync(schema, source);
+      expect(syncResult).to.deep.equal(result);
     });
 
     it('Allows us to query for the ID and friends of R2-D2', async () => {
@@ -165,12 +168,15 @@ describe('Star Wars Query Tests', () => {
   });
 
   describe('Using IDs and query parameters to refetch objects', () => {
-    it('Allows us to query for Luke Skywalker directly, using his ID', async () => {
+    it('Allows us to query characters directly, using their IDs', async () => {
       const source = `
-        query FetchLukeQuery {
+        query FetchLukeAndC3POQuery {
           human(id: "1000") {
             name
           }
+          droid(id: "2000") {
+            name
+          }
         }
       `;
 
@@ -180,6 +186,9 @@ describe('Star Wars Query Tests', () => {
           human: {
             name: 'Luke Skywalker',
           },
+          droid: {
+            name: 'C-3PO',
+          },
         },
       });
     });

src/execution/__tests__/abstract-test.js

@@ -443,6 +443,46 @@ describe('Execute: Handles execution of abstract types', () => {
     });
   });
 
+  it('missing both resolveType and isTypeOf yields useful error', () => {
+    const fooInterface = new GraphQLInterfaceType({
+      name: 'FooInterface',
+      fields: { bar: { type: GraphQLString } },
+    });
+
+    const fooObject = new GraphQLObjectType({
+      name: 'FooObject',
+      fields: { bar: { type: GraphQLString } },
+      interfaces: [fooInterface],
+    });
+
+    const schema = new GraphQLSchema({
+      query: new GraphQLObjectType({
+        name: 'Query',
+        fields: {
+          foo: {
+            type: fooInterface,
+            resolve: () => 'dummy',
+          },
+        },
+      }),
+      types: [fooObject],
+    });
+
+    const result = graphqlSync({ schema, source: '{ foo { bar } }' });
+
+    expect(result).to.deep.equal({
+      data: { foo: null },
+      errors: [
+        {
+          message:
+            'Abstract type "FooInterface" must resolve to an Object type at runtime for field "Query.foo" with value "dummy", received "undefined". Either the "FooInterface" type should provide a "resolveType" function or each possible type should provide an "isTypeOf" function.',
+          locations: [{ line: 1, column: 3 }],
+          path: ['foo'],
+        },
+      ],
+    });
+  });
+
   it('resolveType allows resolving with type name', () => {
     const PetType = new GraphQLInterfaceType({
       name: 'Pet',

src/execution/__tests__/executor-test.js

@@ -44,6 +44,31 @@ describe('Execute: Handles basic execution tasks', () => {
     );
   });
 
+  it('throws on invalid variables', () => {
+    const schema = new GraphQLSchema({
+      query: new GraphQLObjectType({
+        name: 'Type',
+        fields: {
+          fieldA: {
+            type: GraphQLString,
+            args: { argA: { type: GraphQLInt } },
+          },
+        },
+      }),
+    });
+    const document = parse(`
+      query ($a: Int) {
+        fieldA(argA: $a)
+      }
+    `);
+    const variableValues = '{ "a": 1 }';
+
+    // $DisableFlowOnNegativeTest
+    expect(() => execute({ schema, document, variableValues })).to.throw(
+      'Variables must be provided as an Object where each property is a variable value. Perhaps look to see if an unparsed JSON string was provided.',
+    );
+  });
+
   it('accepts positional arguments', () => {
     const schema = new GraphQLSchema({
       query: new GraphQLObjectType({
@@ -77,7 +102,7 @@ describe('Execute: Handles basic execution tasks', () => {
       e: () => 'Egg',
       f: 'Fish',
       // Called only by DataType::pic static resolver
-      pic: size => 'Pic of size: ' + (size || 50),
+      pic: size => 'Pic of size: ' + size,
       deep: () => deepData,
       promise: promiseData,
     };
@@ -908,6 +933,30 @@ describe('Execute: Handles basic execution tasks', () => {
     });
   });
 
+  it('ignores missing sub selections on fields', () => {
+    const someType = new GraphQLObjectType({
+      name: 'SomeType',
+      fields: {
+        b: { type: GraphQLString },
+      },
+    });
+    const schema = new GraphQLSchema({
+      query: new GraphQLObjectType({
+        name: 'Query',
+        fields: {
+          a: { type: someType },
+        },
+      }),
+    });
+    const document = parse('{ a }');
+    const rootValue = { a: { b: 'c' } };
+
+    const result = execute({ schema, document, rootValue });
+    expect(result).to.deep.equal({
+      data: { a: {} },
+    });
+  });
+
   it('does not include illegal fields in output', () => {
     const schema = new GraphQLSchema({
       query: new GraphQLObjectType({
@@ -973,7 +1022,10 @@ describe('Execute: Handles basic execution tasks', () => {
 
     const SpecialType = new GraphQLObjectType({
       name: 'SpecialType',
-      isTypeOf: obj => obj instanceof Special,
+      isTypeOf(obj, context) {
+        const result = obj instanceof Special;
+        return context && context.async ? Promise.resolve(result) : result;
+      },
       fields: { value: { type: GraphQLString } },
     });
 
@@ -1005,6 +1057,10 @@ describe('Execute: Handles basic execution tasks', () => {
         },
       ],
     });
+
+    const contextValue = { async: true };
+    const asyncResult = execute({ schema, document, rootValue, contextValue });
+    expect(asyncResult).to.deep.equal(asyncResult);
   });
 
   it('executes ignoring invalid non-executable definitions', () => {

src/execution/__tests__/mutations-test.js

@@ -137,6 +137,15 @@ describe('Execute: Handles mutation execution ordering', () => {
     });
   });
 
+  it('does not include illegal mutation fields in output', () => {
+    const document = parse('mutation { thisIsIllegalDoNotIncludeMe }');
+
+    const result = execute({ schema, document });
+    expect(result).to.deep.equal({
+      data: {},
+    });
+  });
+
   it('evaluates mutations correctly in the presence of a failed mutation', async () => {
     const document = parse(`
       mutation M {

src/execution/__tests__/nonnull-test.js

@@ -3,6 +3,8 @@
 import { expect } from 'chai';
 import { describe, it } from 'mocha';
 
+import invariant from '../../jsutils/invariant';
+
 import { parse } from '../../language/parser';
 
 import { GraphQLSchema } from '../../type/schema';
@@ -566,9 +568,8 @@ describe('Execute: handles non-nullable types', () => {
               },
             },
             resolve: (_, args) => {
-              if (typeof args.cannotBeNull === 'string') {
-                return 'Passed: ' + args.cannotBeNull;
-              }
+              invariant(typeof args.cannotBeNull === 'string');
+              return 'Passed: ' + args.cannotBeNull;
             },
           },
         },

src/execution/__tests__/union-interface-test.js

@@ -381,6 +381,47 @@ describe('Execute: Union and intersection types', () => {
     });
   });
 
+  it('executes interface types with named fragments', () => {
+    const document = parse(`
+      {
+        __typename
+        name
+        friends {
+          __typename
+          name
+          ...DogBarks
+          ...CatMeows
+        }
+      }
+
+      fragment  DogBarks on Dog {
+        barks
+      }
+
+      fragment  CatMeows on Cat {
+        meows
+      }
+    `);
+
+    expect(execute({ schema, document, rootValue: john })).to.deep.equal({
+      data: {
+        __typename: 'Person',
+        name: 'John',
+        friends: [
+          {
+            __typename: 'Person',
+            name: 'Liz',
+          },
+          {
+            __typename: 'Dog',
+            name: 'Odie',
+            barks: true,
+          },
+        ],
+      },
+    });
+  });
+
   it('allows fragment conditions to be abstract types', () => {
     const document = parse(`
       {

src/execution/__tests__/variables-test.js

@@ -25,23 +25,13 @@ import { getVariableValues } from '../values';
 
 const TestComplexScalar = new GraphQLScalarType({
   name: 'ComplexScalar',
-  serialize(value) {
-    if (value === 'DeserializedValue') {
-      return 'SerializedValue';
-    }
-    return null;
-  },
   parseValue(value) {
-    if (value === 'SerializedValue') {
-      return 'DeserializedValue';
-    }
-    return null;
+    invariant(value === 'SerializedValue');
+    return 'DeserializedValue';
   },
   parseLiteral(ast) {
-    if (ast.value === 'SerializedValue') {
-      return 'DeserializedValue';
-    }
-    return null;
+    invariant(ast.value === 'SerializedValue');
+    return 'DeserializedValue';
   },
 });
 

src/jsutils/__tests__/invariant-test.js

@@ -0,0 +1,16 @@
+// @flow strict
+
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+
+import invariant from '../invariant';
+
+describe('invariant', () => {
+  it('throws on false conditions', () => {
+    expect(() => invariant(false, 'Oops!')).to.throw('Oops!');
+  });
+
+  it('use default error message', () => {
+    expect(() => invariant(false)).to.throw('Unexpected invariant triggered.');
+  });
+});