diff --git a/dist/context.d.ts b/dist/context.d.ts
deleted file mode 100644
index 1ff7390..0000000
--- a/dist/context.d.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-export interface ContextData {
-    models: Object;
-    user: Object;
-}
-export declare const createExpressContext: (data: any, res: any) => Context;
-export declare class Context {
-    models: Object;
-    user: Object;
-    constructor(data: ContextData);
-    dispose(): void;
-}
diff --git a/dist/context.js b/dist/context.js
deleted file mode 100644
index 88b36eb..0000000
--- a/dist/context.js
+++ /dev/null
@@ -1,33 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const assert = require("assert");
-;
-exports.createExpressContext = (data, res) => {
-    data = data || {};
-    data.user = data.user || null;
-    data.models = data.models || {};
-    const context = new Context(data);
-    if (res) {
-        assert(typeof res.once === 'function', 'createExpressContext takes response as second parameter that implements "res.once"');
-        // Bind the response finish event to the context disposal method
-        res.once('finish', () => context && context.dispose ? context.dispose() : null);
-    }
-    return context;
-};
-class Context {
-    constructor(data) {
-        Object.keys(data).forEach(key => {
-            this[key] = data[key];
-        });
-    }
-    dispose() {
-        const models = this.models;
-        const user = this.user;
-        this.models = null;
-        this.user = null;
-        // Call dispose on every attached model that contains a dispose method
-        Object.keys(models).forEach((key) => models[key].dispose ? models[key].dispose() : null);
-    }
-}
-exports.Context = Context;
-//# sourceMappingURL=context.js.map
\ No newline at end of file
diff --git a/dist/context.js.map b/dist/context.js.map
deleted file mode 100644
index a0aa1eb..0000000
--- a/dist/context.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"context.js","sourceRoot":"","sources":["../src/context.ts"],"names":[],"mappings":";;AAAA,iCAAiC;AAIhC,CAAC;AACW,QAAA,oBAAoB,GAAG,CAAC,IAAI,EAAE,GAAG,EAAE,EAAE;IAChD,IAAI,GAAG,IAAI,IAAI,EAAE,CAAC;IAClB,IAAI,CAAC,IAAI,GAAG,IAAI,CAAC,IAAI,IAAI,IAAI,CAAC;IAC9B,IAAI,CAAC,MAAM,GAAG,IAAI,CAAC,MAAM,IAAI,EAAE,CAAC;IAChC,MAAM,OAAO,GAAG,IAAI,OAAO,CAAC,IAAI,CAAC,CAAC;IAClC,IAAI,GAAG,EAAE;QACP,MAAM,CAAC,OAAO,GAAG,CAAC,IAAI,KAAK,UAAU,EAAE,oFAAoF,CAAC,CAAC;QAC7H,gEAAgE;QAChE,GAAG,CAAC,IAAI,CAAC,QAAQ,EAAE,GAAG,EAAE,CAAC,OAAO,IAAI,OAAO,CAAC,OAAO,CAAC,CAAC,CAAC,OAAO,CAAC,OAAO,EAAE,CAAC,CAAC,CAAC,IAAI,CAAC,CAAC;KACjF;IACD,OAAO,OAAO,CAAC;AACjB,CAAC,CAAC;AAEF;IAGE,YAAa,IAAiB;QAC5B,MAAM,CAAC,IAAI,CAAC,IAAI,CAAC,CAAC,OAAO,CAAC,GAAG,CAAC,EAAE;YAC9B,IAAI,CAAC,GAAG,CAAC,GAAG,IAAI,CAAC,GAAG,CAAC,CAAA;QACvB,CAAC,CAAC,CAAC;IACL,CAAC;IACD,OAAO;QACL,MAAM,MAAM,GAAG,IAAI,CAAC,MAAM,CAAC;QAC3B,MAAM,IAAI,GAAG,IAAI,CAAC,IAAI,CAAC;QACvB,IAAI,CAAC,MAAM,GAAG,IAAI,CAAC;QACnB,IAAI,CAAC,IAAI,GAAG,IAAI,CAAC;QACjB,sEAAsE;QACtE,MAAM,CAAC,IAAI,CAAC,MAAM,CAAC,CAAC,OAAO,CAAC,CAAC,GAAG,EAAE,EAAE,CAAC,MAAM,CAAC,GAAG,CAAC,CAAC,OAAO,CAAC,CAAC,CAAC,MAAM,CAAC,GAAG,CAAC,CAAC,OAAO,EAAE,CAAC,CAAC,CAAC,IAAI,CAAC,CAAC;IAC3F,CAAC;CACF;AAhBD,0BAgBC"}
\ No newline at end of file
diff --git a/dist/helper.d.ts b/dist/helper.d.ts
deleted file mode 100644
index 606f240..0000000
--- a/dist/helper.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export declare const combineResolvers: (resolvers?: any[]) => any;
-export declare const and: (...conditions: any[]) => (resolver: any) => any;
-export declare const or: (...conditions: any[]) => (resolver: any) => (...query: any[]) => Promise<{}>;
diff --git a/dist/helper.js b/dist/helper.js
deleted file mode 100644
index c8c136e..0000000
--- a/dist/helper.js
+++ /dev/null
@@ -1,30 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const merge = require("deepmerge");
-// Helper function to combine multiple resolver definition hashes into a single hash for consumption by Apollostack's graphql-server
-exports.combineResolvers = (resolvers = []) => resolvers
-    .reduce((combined, resolver) => merge(combined, resolver));
-// Accepts multiple authentication resolvers and returns a function which will be called
-// if all of the authentication resolvers succeed, or throw an error if one of them fails
-exports.and = (...conditions) => resolver => {
-    return conditions.reduceRight((p, c) => {
-        return c.createResolver(p);
-    }, resolver);
-};
-// Accepts multiple authentication resolvers and returns a function which will be called
-// if any of the authentication resolvers succeed, or throw an error if all of them fail
-exports.or = (...conditions) => resolver => (...query) => {
-    return new Promise((resolve, reject) => {
-        let limit = conditions.length - 1;
-        const attempt = (i) => conditions[i].createResolver(resolver)(...query)
-            .then(res => resolve(res))
-            .catch(err => {
-            if (i === limit)
-                reject(err);
-            else
-                attempt(i + 1);
-        });
-        attempt(0);
-    });
-};
-//# sourceMappingURL=helper.js.map
\ No newline at end of file
diff --git a/dist/helper.js.map b/dist/helper.js.map
deleted file mode 100644
index 6602270..0000000
--- a/dist/helper.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"helper.js","sourceRoot":"","sources":["../src/helper.ts"],"names":[],"mappings":";;AAAA,mCAAmC;AAEnC,oIAAoI;AACvH,QAAA,gBAAgB,GAAG,CAAC,SAAS,GAAG,EAAE,EAAE,EAAE,CAAC,SAAS;KAC1D,MAAM,CAAC,CAAC,QAAQ,EAAE,QAAQ,EAAE,EAAE,CAAC,KAAK,CAAC,QAAQ,EAAE,QAAQ,CAAC,CAAC,CAAC;AAE7D,wFAAwF;AACxF,yFAAyF;AAC5E,QAAA,GAAG,GAAG,CAAC,GAAG,UAAU,EAAE,EAAE,CAAC,QAAQ,CAAC,EAAE;IAC/C,OAAO,UAAU,CAAC,WAAW,CAAC,CAAC,CAAC,EAAE,CAAC,EAAE,EAAE;QACrC,OAAO,CAAC,CAAC,cAAc,CAAC,CAAC,CAAC,CAAC;IAC7B,CAAC,EAAE,QAAQ,CAAC,CAAA;AACd,CAAC,CAAA;AAED,wFAAwF;AACxF,wFAAwF;AAC3E,QAAA,EAAE,GAAG,CAAC,GAAG,UAAU,EAAE,EAAE,CAAC,QAAQ,CAAC,EAAE,CAAC,CAAC,GAAG,KAAK,EAAE,EAAE;IAC5D,OAAO,IAAI,OAAO,CAAC,CAAC,OAAO,EAAE,MAAM,EAAE,EAAE;QACrC,IAAI,KAAK,GAAG,UAAU,CAAC,MAAM,GAAG,CAAC,CAAC;QAClC,MAAM,OAAO,GAAG,CAAC,CAAC,EAAE,EAAE,CACpB,UAAU,CAAC,CAAC,CAAC,CAAC,cAAc,CAAC,QAAQ,CAAC,CAAC,GAAG,KAAK,CAAC;aAC7C,IAAI,CAAC,GAAG,CAAC,EAAE,CAAC,OAAO,CAAC,GAAG,CAAC,CAAC;aACzB,KAAK,CAAC,GAAG,CAAC,EAAE;YACX,IAAG,CAAC,KAAK,KAAK;gBAAE,MAAM,CAAC,GAAG,CAAC,CAAC;;gBACvB,OAAO,CAAC,CAAC,GAAG,CAAC,CAAC,CAAC;QACtB,CAAC,CAAC,CAAC;QACP,OAAO,CAAC,CAAC,CAAC,CAAC;IACb,CAAC,CAAC,CAAC;AACL,CAAC,CAAA"}
\ No newline at end of file
diff --git a/dist/index.d.ts b/dist/index.d.ts
deleted file mode 100644
index 8be43e8..0000000
--- a/dist/index.d.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import { usePromise } from './promise';
-import { combineResolvers } from './helper';
-import { createExpressContext } from './context';
-import { createResolver } from './resolver';
-export { usePromise, combineResolvers, createExpressContext, createResolver };
diff --git a/dist/index.js b/dist/index.js
deleted file mode 100644
index c1bd5b2..0000000
--- a/dist/index.js
+++ /dev/null
@@ -1,11 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const promise_1 = require("./promise");
-exports.usePromise = promise_1.usePromise;
-const helper_1 = require("./helper");
-exports.combineResolvers = helper_1.combineResolvers;
-const context_1 = require("./context");
-exports.createExpressContext = context_1.createExpressContext;
-const resolver_1 = require("./resolver");
-exports.createResolver = resolver_1.createResolver;
-//# sourceMappingURL=index.js.map
\ No newline at end of file
diff --git a/dist/index.js.map b/dist/index.js.map
deleted file mode 100644
index 24bc5a2..0000000
--- a/dist/index.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"index.js","sourceRoot":"","sources":["../src/index.ts"],"names":[],"mappings":";;AAAA,uCAAuC;AAMrC,qBANO,oBAAU,CAMP;AALZ,qCAA4C;AAM1C,2BANO,yBAAgB,CAMP;AALlB,uCAAiD;AAM/C,+BANO,8BAAoB,CAMP;AALtB,yCAA4C;AAM1C,yBANO,yBAAc,CAMP"}
\ No newline at end of file
diff --git a/dist/promise.d.ts b/dist/promise.d.ts
deleted file mode 100644
index c69594c..0000000
--- a/dist/promise.d.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-export declare const usePromise: (pLib: any) => void;
-export declare const getPromise: () => PromiseConstructor;
diff --git a/dist/promise.js b/dist/promise.js
deleted file mode 100644
index a8ffab7..0000000
--- a/dist/promise.js
+++ /dev/null
@@ -1,18 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const assert = require("assert");
-// Expose the Promise constructor so that it can be overwritten by a different lib like Bluebird
-let p = Promise;
-// Allow overload with compliant promise lib
-exports.usePromise = pLib => {
-    assert(pLib && pLib.prototype, 'apollo-errors#usePromise expects a valid Promise library');
-    assert(!!pLib.resolve, 'apollo-errors#usePromise expects a Promise library that implements static method "Promise.resolve"');
-    assert(!!pLib.reject, 'apollo-errors#usePromise expects a Promise library that implements static method "Promise.reject"');
-    assert(!!pLib.all, 'apollo-errors#usePromise expects a Promise library that implements static method "Promise.all"');
-    assert(!!pLib.prototype.then, 'apollo-errors#usePromise expects a Promise library that implements method "promise.then" on the constructor prototype');
-    assert(!!pLib.prototype.catch, 'apollo-errors#usePromise expects a Promise library that implements method "promise.catch" on the constructor prototype');
-    p = pLib;
-};
-// Return the currently selected promise lib
-exports.getPromise = () => p;
-//# sourceMappingURL=promise.js.map
\ No newline at end of file
diff --git a/dist/promise.js.map b/dist/promise.js.map
deleted file mode 100644
index 164c5ba..0000000
--- a/dist/promise.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"promise.js","sourceRoot":"","sources":["../src/promise.ts"],"names":[],"mappings":";;AAAA,iCAAiC;AAEjC,gGAAgG;AAChG,IAAI,CAAC,GAAG,OAAO,CAAC;AAEhB,4CAA4C;AAC/B,QAAA,UAAU,GAAG,IAAI,CAAC,EAAE;IAC/B,MAAM,CAAC,IAAI,IAAI,IAAI,CAAC,SAAS,EAAE,0DAA0D,CAAC,CAAC;IAC3F,MAAM,CAAC,CAAC,CAAC,IAAI,CAAC,OAAO,EAAE,oGAAoG,CAAC,CAAC;IAC7H,MAAM,CAAC,CAAC,CAAC,IAAI,CAAC,MAAM,EAAE,mGAAmG,CAAC,CAAC;IAC3H,MAAM,CAAC,CAAC,CAAC,IAAI,CAAC,GAAG,EAAE,gGAAgG,CAAC,CAAC;IACrH,MAAM,CAAC,CAAC,CAAC,IAAI,CAAC,SAAS,CAAC,IAAI,EAAE,uHAAuH,CAAC,CAAC;IACvJ,MAAM,CAAC,CAAC,CAAC,IAAI,CAAC,SAAS,CAAC,KAAK,EAAE,wHAAwH,CAAC,CAAC;IACzJ,CAAC,GAAG,IAAI,CAAC;AACX,CAAC,CAAC;AAEF,4CAA4C;AAC/B,QAAA,UAAU,GAAG,GAAG,EAAE,CAAC,CAAC,CAAC"}
\ No newline at end of file
diff --git a/dist/resolver.d.ts b/dist/resolver.d.ts
deleted file mode 100644
index 0f966db..0000000
--- a/dist/resolver.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-export declare const createResolver: (resFn: any, errFn: any) => (root: any, args?: {}, context?: {}, info?: {}) => Promise<any>;
diff --git a/dist/resolver.js b/dist/resolver.js
deleted file mode 100644
index d505d4d..0000000
--- a/dist/resolver.js
+++ /dev/null
@@ -1,60 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const promise_1 = require("./promise");
-const util_1 = require("./util");
-exports.createResolver = (resFn, errFn) => {
-    const Promise = promise_1.getPromise();
-    const baseResolver = (root, args = {}, context = {}, info = {}) => {
-        // Return resolving promise with `null` if the resolver function param is not a function
-        if (!util_1.isFunction(resFn))
-            return Promise.resolve(null);
-        return util_1.Promisify(resFn)(root, args, context, info).catch(e => {
-            // On error, check if there is an error handler.  If not, throw the original error
-            if (!util_1.isFunction(errFn))
-                throw e;
-            // Call the error handler.
-            return util_1.Promisify(errFn)(root, args, context, e).then(parsedError => {
-                // If it resolves, throw the resolving value or the original error.
-                throw parsedError || e;
-            }, parsedError => {
-                // If it rejects, throw the rejecting value or the original error
-                throw parsedError || e;
-            });
-        });
-    };
-    baseResolver['createResolver'] = (cResFn, cErrFn) => {
-        const Promise = promise_1.getPromise();
-        const childResFn = (root, args, context, info = {}) => {
-            // Start with either the parent resolver function or a no-op (returns null)
-            const entry = util_1.isFunction(resFn) ? util_1.Promisify(resFn)(root, args, context, info) : Promise.resolve(null);
-            return entry.then(r => {
-                // If the parent returns a value, continue
-                if (util_1.isNotNullOrUndefined(r))
-                    return r;
-                // Call the child resolver function or a no-op (returns null)
-                return util_1.isFunction(cResFn) ? util_1.Promisify(cResFn)(root, args, context) : Promise.resolve(null);
-            });
-        };
-        const childErrFn = (root, args, context, err) => {
-            // Start with either the child error handler or a no-op (returns null)
-            const entry = util_1.isFunction(cErrFn) ? util_1.Promisify(cErrFn)(root, args, context, err) : Promise.resolve(null);
-            return entry.then(r => {
-                // If the child returns a value, throw it
-                if (util_1.isNotNullOrUndefined(r))
-                    throw r;
-                // Call the parent error handler or a no-op (returns null)
-                return util_1.isFunction(errFn) ? util_1.Promisify(errFn)(root, args, context, err).then(e => {
-                    // If it resolves, throw the resolving value or the original error
-                    throw e || err;
-                }, e => {
-                    // If it rejects, throw the rejecting value or the original error
-                    throw e || err;
-                }) : Promise.resolve(null);
-            });
-        };
-        // Create the child resolver and return it
-        return exports.createResolver(childResFn, childErrFn);
-    };
-    return baseResolver;
-};
-//# sourceMappingURL=resolver.js.map
\ No newline at end of file
diff --git a/dist/resolver.js.map b/dist/resolver.js.map
deleted file mode 100644
index ef15a6c..0000000
--- a/dist/resolver.js.map
+++ /dev/null
@@ -1 +0,0 @@
-{"version":3,"file":"resolver.js","sourceRoot":"","sources":["../src/resolver.ts"],"names":[],"mappings":";;AAAA,uCAAuC;AACvC,iCAAqE;AAGxD,QAAA,cAAc,GAAG,CAAC,KAAK,EAAE,KAAK,EAAE,EAAE;IAC7C,MAAM,OAAO,GAAG,oBAAU,EAAE,CAAC;IAC7B,MAAM,YAAY,GAAG,CAAC,IAAI,EAAE,IAAI,GAAG,EAAE,EAAE,OAAO,GAAG,EAAE,EAAE,IAAI,GAAG,EAAE,EAAE,EAAE;QAChE,wFAAwF;QACxF,IAAI,CAAC,iBAAU,CAAC,KAAK,CAAC;YAAE,OAAO,OAAO,CAAC,OAAO,CAAC,IAAI,CAAC,CAAC;QACrD,OAAO,gBAAS,CAAC,KAAK,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,IAAI,CAAC,CAAC,KAAK,CAAC,CAAC,CAAC,EAAE;YAC3D,kFAAkF;YAClF,IAAI,CAAC,iBAAU,CAAC,KAAK,CAAC;gBAAE,MAAM,CAAC,CAAC;YAChC,0BAA0B;YAC1B,OAAO,gBAAS,CAAC,KAAK,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,CAAC,CAAC,CAAC,IAAI,CAAC,WAAW,CAAC,EAAE;gBACjE,mEAAmE;gBACnE,MAAM,WAAW,IAAI,CAAC,CAAA;YACxB,CAAC,EAAE,WAAW,CAAC,EAAE;gBACf,iEAAiE;gBACjE,MAAM,WAAW,IAAI,CAAC,CAAA;YACxB,CAAC,CAAC,CAAC;QACL,CAAC,CAAC,CAAC;IACL,CAAC,CAAC;IACF,YAAY,CAAC,gBAAgB,CAAC,GAAG,CAAC,MAAM,EAAE,MAAM,EAAE,EAAE;QAClD,MAAM,OAAO,GAAG,oBAAU,EAAE,CAAC;QAE7B,MAAM,UAAU,GAAG,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,IAAI,GAAG,EAAE,EAAE,EAAE;YACpD,2EAA2E;YAC3E,MAAM,KAAK,GAAG,iBAAU,CAAC,KAAK,CAAC,CAAC,CAAC,CAAC,gBAAS,CAAC,KAAK,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,IAAI,CAAC,CAAC,CAAC,CAAC,OAAO,CAAC,OAAO,CAAC,IAAI,CAAC,CAAC;YACtG,OAAO,KAAK,CAAC,IAAI,CAAC,CAAC,CAAC,EAAE;gBACpB,0CAA0C;gBAC1C,IAAI,2BAAoB,CAAC,CAAC,CAAC;oBAAE,OAAO,CAAC,CAAC;gBACtC,6DAA6D;gBAC7D,OAAO,iBAAU,CAAC,MAAM,CAAC,CAAC,CAAC,CAAC,gBAAS,CAAC,MAAM,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,CAAC,CAAC,CAAC,CAAC,OAAO,CAAC,OAAO,CAAC,IAAI,CAAC,CAAC;YAC7F,CAAC,CAAC,CAAC;QACL,CAAC,CAAC;QAEF,MAAM,UAAU,GAAG,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,GAAG,EAAE,EAAE;YAC9C,sEAAsE;YACtE,MAAM,KAAK,GAAG,iBAAU,CAAC,MAAM,CAAC,CAAC,CAAC,CAAC,gBAAS,CAAC,MAAM,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,GAAG,CAAC,CAAC,CAAC,CAAC,OAAO,CAAC,OAAO,CAAC,IAAI,CAAC,CAAC;YAEvG,OAAO,KAAK,CAAC,IAAI,CAAC,CAAC,CAAC,EAAE;gBACpB,yCAAyC;gBACzC,IAAI,2BAAoB,CAAC,CAAC,CAAC;oBAAE,MAAM,CAAC,CAAC;gBACrC,0DAA0D;gBAC1D,OAAO,iBAAU,CAAC,KAAK,CAAC,CAAC,CAAC,CAAC,gBAAS,CAAC,KAAK,CAAC,CAAC,IAAI,EAAE,IAAI,EAAE,OAAO,EAAE,GAAG,CAAC,CAAC,IAAI,CAAC,CAAC,CAAC,EAAE;oBAC7E,kEAAkE;oBAClE,MAAM,CAAC,IAAI,GAAG,CAAC;gBACjB,CAAC,EAAE,CAAC,CAAC,EAAE;oBACL,iEAAiE;oBACjE,MAAM,CAAC,IAAI,GAAG,CAAC;gBACjB,CAAC,CAAC,CAAC,CAAC,CAAC,OAAO,CAAC,OAAO,CAAC,IAAI,CAAC,CAAC;YAC7B,CAAC,CAAC,CAAC;QACL,CAAC,CAAC;QAEF,0CAA0C;QAC1C,OAAO,sBAAc,CAAC,UAAU,EAAE,UAAU,CAAC,CAAC;IAChD,CAAC,CAAA;IAED,OAAO,YAAY,CAAC;AACtB,CAAC,CAAC"}
\ No newline at end of file
diff --git a/dist/util.d.ts b/dist/util.d.ts
deleted file mode 100644
index 1d83213..0000000
--- a/dist/util.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export declare const isFunction: (fn: any) => boolean;
-export declare const Promisify: (fn: any) => (...args: any[]) => Promise<{}>;
-export declare const isNotNullOrUndefined: (val: any) => boolean;
diff --git a/dist/util.js b/dist/util.js
deleted file mode 100644
index 30313ca..0000000
--- a/dist/util.js
+++ /dev/null
@@ -1,17 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const promise_1 = require("./promise");
-exports.isFunction = fn => typeof fn === 'function';
-exports.Promisify = fn => {
-    const Promise = promise_1.getPromise();
-    return (...args) => new Promise((resolve, reject) => {
-        try {
-            return Promise.resolve(fn(...args)).then(r => resolve(r), e => reject(e));
-        }
-        catch (e) {
-            return reject(e);
-        }
-    });
-};
-exports.isNotNullOrUndefined = val => val !== null && val !== undefined;
-//# sourceMappingURL=util.js.map
\ No newline at end of file
diff --git a/dist/util.js.map b/dist/util.js.map
deleted file mode 100644
index d1a4263..0000000
--- a/dist/util.js.map
+++ /dev/null
@@ -1 +0,0 @@
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\ No newline at end of file
diff --git a/src/resolver.ts b/src/resolver.ts
index c9c2207..a734582 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -1,10 +1,28 @@
 import { getPromise } from './promise';
 import { isFunction, Promisify, isNotNullOrUndefined } from './util';
 
+const Promise = getPromise();
 
-export const createResolver = (resFn, errFn) => {
+export interface ResultFunction<ResulType> {
+  (root, args, context, info): Promise<ResulType> | ResulType | void
+}
+
+export interface ErrorFunction<ErrorType> {
+  (root, args, context, err): ErrorType | void
+}
+
+export interface CreateResolverFunction {
+  <R, E>(resFn: ResultFunction<R>, errFn?: ErrorFunction<E>): Resolver<R>
+}
+
+export interface Resolver<ResulType> {
+  (root, args: {}, context: {}, info: {}): Promise<ResulType>
+  createResolver?: CreateResolverFunction
+}
+
+export const createResolver: CreateResolverFunction = <R, E>(resFn: ResultFunction<R>, errFn: ErrorFunction<E>) => {
   const Promise = getPromise();
-  const baseResolver = (root, args = {}, context = {}, info = {}) => {
+  const baseResolver: Resolver<R> = (root, args = {}, context = {}, info = {}) => {
     // Return resolving promise with `null` if the resolver function param is not a function
     if (!isFunction(resFn)) return Promise.resolve(null);
     return Promisify(resFn)(root, args, context, info).catch(e => {
@@ -20,7 +38,7 @@ export const createResolver = (resFn, errFn) => {
       });
     });
   };
-  baseResolver['createResolver'] = (cResFn, cErrFn) => {
+  baseResolver.createResolver = (cResFn, cErrFn) => {
     const Promise = getPromise();
 
     const childResFn = (root, args, context, info = {}) => {
diff --git a/src/util.ts b/src/util.ts
index 8fad04c..55a28d2 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -1,6 +1,6 @@
 import { getPromise } from './promise';
 
-export const isFunction = fn => typeof fn === 'function';
+export const isFunction = fn => typeof fn === 'function' || fn instanceof Function;
 
 export const Promisify = fn => {
   const Promise = getPromise();