@kamilkisiela/graphql-tools
Version:
Useful tools to create and manipulate GraphQL schemas.
306 lines • 14.9 kB
JavaScript
Object.defineProperty(exports, "__esModule", { value: true });
var graphql_1 = require("graphql");
var uuid = require("uuid");
var makeExecutableSchema_1 = require("./makeExecutableSchema");
// This function wraps addMockFunctionsToSchema for more convenience
function mockServer(schema, mocks, preserveResolvers) {
if (preserveResolvers === void 0) { preserveResolvers = false; }
var mySchema;
if (!(schema instanceof graphql_1.GraphQLSchema)) {
// TODO: provide useful error messages here if this fails
mySchema = makeExecutableSchema_1.buildSchemaFromTypeDefinitions(schema);
}
else {
mySchema = schema;
}
addMockFunctionsToSchema({ schema: mySchema, mocks: mocks, preserveResolvers: preserveResolvers });
return { query: function (query, vars) { return graphql_1.graphql(mySchema, query, {}, {}, vars); } };
}
exports.mockServer = mockServer;
var defaultMockMap = new Map();
defaultMockMap.set('Int', function () { return Math.round(Math.random() * 200) - 100; });
defaultMockMap.set('Float', function () { return Math.random() * 200 - 100; });
defaultMockMap.set('String', function () { return 'Hello World'; });
defaultMockMap.set('Boolean', function () { return Math.random() > 0.5; });
defaultMockMap.set('ID', function () { return uuid.v4(); });
// TODO allow providing a seed such that lengths of list could be deterministic
// this could be done by using casual to get a random list length if the casual
// object is global.
function addMockFunctionsToSchema(_a) {
var schema = _a.schema, _b = _a.mocks, mocks = _b === void 0 ? {} : _b, _c = _a.preserveResolvers, preserveResolvers = _c === void 0 ? false : _c;
if (!schema) {
throw new Error('Must provide schema to mock');
}
if (!(schema instanceof graphql_1.GraphQLSchema)) {
throw new Error('Value at "schema" must be of type GraphQLSchema');
}
if (!isObject(mocks)) {
throw new Error('mocks must be of type Object');
}
// use Map internally, because that API is nicer.
var mockFunctionMap = new Map();
Object.keys(mocks).forEach(function (typeName) {
mockFunctionMap.set(typeName, mocks[typeName]);
});
mockFunctionMap.forEach(function (mockFunction, mockTypeName) {
if (typeof mockFunction !== 'function') {
throw new Error("mockFunctionMap[" + mockTypeName + "] must be a function");
}
});
var mockType = function (type, typeName, fieldName) {
// order of precendence for mocking:
// 1. if the object passed in already has fieldName, just use that
// --> if it's a function, that becomes your resolver
// --> if it's a value, the mock resolver will return that
// 2. if the nullableType is a list, recurse
// 2. if there's a mock defined for this typeName, that will be used
// 3. if there's no mock defined, use the default mocks for this type
return function (root, args, context, info) {
// nullability doesn't matter for the purpose of mocking.
var fieldType = graphql_1.getNullableType(type);
var namedFieldType = graphql_1.getNamedType(fieldType);
if (root && typeof root[fieldName] !== 'undefined') {
var result = void 0;
// if we're here, the field is already defined
if (typeof root[fieldName] === 'function') {
result = root[fieldName](root, args, context, info);
if (result instanceof MockList) {
result = result.mock(root, args, context, info, fieldType, mockType);
}
}
else {
result = root[fieldName];
}
// Now we merge the result with the default mock for this type.
// This allows overriding defaults while writing very little code.
if (mockFunctionMap.has(namedFieldType.name)) {
result = mergeMocks(mockFunctionMap
.get(namedFieldType.name)
.bind(null, root, args, context, info), result);
}
return result;
}
if (fieldType instanceof graphql_1.GraphQLList ||
fieldType instanceof graphql_1.GraphQLNonNull) {
return [
mockType(fieldType.ofType)(root, args, context, info),
mockType(fieldType.ofType)(root, args, context, info),
];
}
if (mockFunctionMap.has(fieldType.name) &&
!(fieldType instanceof graphql_1.GraphQLUnionType ||
fieldType instanceof graphql_1.GraphQLInterfaceType)) {
// the object passed doesn't have this field, so we apply the default mock
return mockFunctionMap.get(fieldType.name)(root, args, context, info);
}
if (fieldType instanceof graphql_1.GraphQLObjectType) {
// objects don't return actual data, we only need to mock scalars!
return {};
}
// if a mock function is provided for unionType or interfaceType, execute it to resolve the concrete type
// otherwise randomly pick a type from all implementation types
if (fieldType instanceof graphql_1.GraphQLUnionType ||
fieldType instanceof graphql_1.GraphQLInterfaceType) {
var implementationType = void 0;
if (mockFunctionMap.has(fieldType.name)) {
var interfaceMockObj = mockFunctionMap.get(fieldType.name)(root, args, context, info);
if (!interfaceMockObj || !interfaceMockObj.__typename) {
return Error("Please return a __typename in \"" + fieldType.name + "\"");
}
implementationType = schema.getType(interfaceMockObj.__typename);
}
else {
var possibleTypes = schema.getPossibleTypes(fieldType);
implementationType = getRandomElement(possibleTypes);
}
return Object.assign({ __typename: implementationType }, mockType(implementationType)(root, args, context, info));
}
if (fieldType instanceof graphql_1.GraphQLEnumType) {
return getRandomElement(fieldType.getValues()).value;
}
if (defaultMockMap.has(fieldType.name)) {
return defaultMockMap.get(fieldType.name)(root, args, context, info);
}
// if we get to here, we don't have a value, and we don't have a mock for this type,
// we could return undefined, but that would be hard to debug, so we throw instead.
// however, we returning it instead of throwing it, so preserveResolvers can handle the failures.
return Error("No mock defined for type \"" + fieldType.name + "\"");
};
};
makeExecutableSchema_1.forEachField(schema, function (field, typeName, fieldName) {
assignResolveType(field.type, preserveResolvers);
var mockResolver;
// we have to handle the root mutation and root query types differently,
// because no resolver is called at the root.
/* istanbul ignore next: Must provide schema DefinitionNode with query type or a type named Query. */
var isOnQueryType = schema.getQueryType() && schema.getQueryType().name === typeName;
var isOnMutationType = schema.getMutationType() && schema.getMutationType().name === typeName;
if (isOnQueryType || isOnMutationType) {
if (mockFunctionMap.has(typeName)) {
var rootMock_1 = mockFunctionMap.get(typeName);
// XXX: BUG in here, need to provide proper signature for rootMock.
if (typeof rootMock_1(undefined, {}, {}, {})[fieldName] === 'function') {
mockResolver = function (root, args, context, info) {
var updatedRoot = root || {}; // TODO: should we clone instead?
updatedRoot[fieldName] = rootMock_1(root, args, context, info)[fieldName];
// XXX this is a bit of a hack to still use mockType, which
// lets you mock lists etc. as well
// otherwise we could just set field.resolve to rootMock()[fieldName]
// it's like pretending there was a resolve function that ran before
// the root resolve function.
return mockType(field.type, typeName, fieldName)(updatedRoot, args, context, info);
};
}
}
}
if (!mockResolver) {
mockResolver = mockType(field.type, typeName, fieldName);
}
if (!preserveResolvers || !field.resolve) {
field.resolve = mockResolver;
}
else {
var oldResolver_1 = field.resolve;
field.resolve = function (rootObject, args, context, info) {
return Promise.all([
mockResolver(rootObject, args, context, info),
oldResolver_1(rootObject, args, context, info),
]).then(function (values) {
var mockedValue = values[0], resolvedValue = values[1];
// In case we couldn't mock
if (mockedValue instanceof Error) {
// only if value was not resolved, populate the error.
if (undefined === resolvedValue) {
throw mockedValue;
}
return resolvedValue;
}
if (resolvedValue instanceof Date && mockedValue instanceof Date) {
return undefined !== resolvedValue ? resolvedValue : mockedValue;
}
if (isObject(mockedValue) && isObject(resolvedValue)) {
// Object.assign() won't do here, as we need to all properties, including
// the non-enumerable ones and defined using Object.defineProperty
var emptyObject = Object.create(Object.getPrototypeOf(resolvedValue));
return copyOwnProps(emptyObject, resolvedValue, mockedValue);
}
return undefined !== resolvedValue ? resolvedValue : mockedValue;
});
};
}
});
}
exports.addMockFunctionsToSchema = addMockFunctionsToSchema;
function isObject(thing) {
return thing === Object(thing) && !Array.isArray(thing);
}
// returns a random element from that ary
function getRandomElement(ary) {
var sample = Math.floor(Math.random() * ary.length);
return ary[sample];
}
function mergeObjects(a, b) {
return Object.assign(a, b);
}
function copyOwnPropsIfNotPresent(target, source) {
Object.getOwnPropertyNames(source).forEach(function (prop) {
if (!Object.getOwnPropertyDescriptor(target, prop)) {
Object.defineProperty(target, prop, Object.getOwnPropertyDescriptor(source, prop));
}
});
}
function copyOwnProps(target) {
var sources = [];
for (var _i = 1; _i < arguments.length; _i++) {
sources[_i - 1] = arguments[_i];
}
sources.forEach(function (source) {
var chain = source;
while (chain) {
copyOwnPropsIfNotPresent(target, chain);
chain = Object.getPrototypeOf(chain);
}
});
return target;
}
// takes either an object or a (possibly nested) array
// and completes the customMock object with any fields
// defined on genericMock
// only merges objects or arrays. Scalars are returned as is
function mergeMocks(genericMockFunction, customMock) {
if (Array.isArray(customMock)) {
return customMock.map(function (el) { return mergeMocks(genericMockFunction, el); });
}
if (isObject(customMock)) {
return mergeObjects(genericMockFunction(), customMock);
}
return customMock;
}
function getResolveType(namedFieldType) {
if (namedFieldType instanceof graphql_1.GraphQLInterfaceType ||
namedFieldType instanceof graphql_1.GraphQLUnionType) {
return namedFieldType.resolveType;
}
else {
return undefined;
}
}
function assignResolveType(type, preserveResolvers) {
var fieldType = graphql_1.getNullableType(type);
var namedFieldType = graphql_1.getNamedType(fieldType);
var oldResolveType = getResolveType(namedFieldType);
if (preserveResolvers && oldResolveType && oldResolveType.length) {
return;
}
if (namedFieldType instanceof graphql_1.GraphQLUnionType ||
namedFieldType instanceof graphql_1.GraphQLInterfaceType) {
// the default `resolveType` always returns null. We add a fallback
// resolution that works with how unions and interface are mocked
namedFieldType.resolveType = function (data, context, info) {
return info.schema.getType(data.__typename);
};
}
}
var MockList = /** @class */ (function () {
// wrappedFunction can return another MockList or a value
function MockList(len, wrappedFunction) {
this.len = len;
if (typeof wrappedFunction !== 'undefined') {
if (typeof wrappedFunction !== 'function') {
throw new Error('Second argument to MockList must be a function or undefined');
}
this.wrappedFunction = wrappedFunction;
}
}
MockList.prototype.mock = function (root, args, context, info, fieldType, mockTypeFunc) {
var arr;
if (Array.isArray(this.len)) {
arr = new Array(this.randint(this.len[0], this.len[1]));
}
else {
arr = new Array(this.len);
}
for (var i = 0; i < arr.length; i++) {
if (typeof this.wrappedFunction === 'function') {
var res = this.wrappedFunction(root, args, context, info);
if (res instanceof MockList) {
var nullableType = graphql_1.getNullableType(fieldType.ofType);
arr[i] = res.mock(root, args, context, info, nullableType, mockTypeFunc);
}
else {
arr[i] = res;
}
}
else {
arr[i] = mockTypeFunc(fieldType.ofType)(root, args, context, info);
}
}
return arr;
};
MockList.prototype.randint = function (low, high) {
return Math.floor(Math.random() * (high - low + 1) + low);
};
return MockList;
}());
exports.MockList = MockList;
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