diff --git a/.editorconfig b/.editorconfig
index ec33772..83c1115 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -1,6 +1,6 @@
 root = true
 
-[*.ts]
+[*.{ts,json}]
 charset = utf-8
 end_of_line = lf
 insert_final_newline = true
diff --git a/comparison.test.ts b/comparison.test.ts
index 67d793b..8195e13 100644
--- a/comparison.test.ts
+++ b/comparison.test.ts
@@ -1,58 +1,58 @@
-import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { bool, cmp, is } from "./comparison.ts";
 
-Deno.test("cmp", () => {
-  assertEquals([8, 3, 5].sort(cmp()), [3, 5, 8]);
-  assertEquals([8, 3, 5, 8].sort(cmp({ reverse: true })), [8, 8, 5, 3]);
-  assertEquals([-2, 8, -7].sort(cmp({ key: Math.abs })), [-2, -7, 8]);
-  assertEquals(["c", "a", "b"].sort(cmp()), ["a", "b", "c"]);
+test("cmp", () => {
+  expect([8, 3, 5].sort(cmp())).toEqual([3, 5, 8]);
+  expect([8, 3, 5, 8].sort(cmp({ reverse: true }))).toEqual([8, 8, 5, 3]);
+  expect([-2, 8, -7].sort(cmp({ key: Math.abs }))).toEqual([-2, -7, 8]);
+  expect(["c", "a", "b"].sort(cmp())).toEqual(["a", "b", "c"]);
 });
 
-Deno.test("is", () => {
+test("is", () => {
   const f1 = is(5);
-  assertEquals(f1(5), true);
-  assertEquals(f1(4), false);
-  assertEquals(f1("a" as any), false);
-  assertEquals(f1(null as any), false);
-  assertEquals(f1(undefined as any), false);
+  expect(f1(5)).toBe(true);
+  expect(f1(4)).toBe(false);
+  expect(f1("a" as any)).toBe(false);
+  expect(f1(null as any)).toBe(false);
+  expect(f1(undefined as any)).toBe(false);
 
   const obj: { x: number } = { x: 1 };
   let f2 = is(obj);
-  assertEquals(f2(obj), true);
-  assertEquals(f2({ x: 1 }), false);
-  assertEquals(f2({ y: 1 } as any), false);
+  expect(f2(obj)).toBe(true);
+  expect(f2({ x: 1 })).toBe(false);
+  expect(f2({ y: 1 } as any)).toBe(false);
 });
 
-Deno.test("bool", () => {
-  assertEquals(bool(null), false);
-  assertEquals(bool(undefined), false);
+test("bool", () => {
+  expect(bool(null)).toBe(false);
+  expect(bool(undefined)).toBe(false);
 
-  assertEquals(bool(false), false);
-  assertEquals(bool(true), true);
+  expect(bool(false)).toBe(false);
+  expect(bool(true)).toBe(true);
 
-  assertEquals(bool(-1), true);
-  assertEquals(bool(0), false);
-  assertEquals(bool(1), true);
+  expect(bool(-1)).toBe(true);
+  expect(bool(0)).toBe(false);
+  expect(bool(1)).toBe(true);
 
-  assertEquals(bool(""), false);
-  assertEquals(bool(" "), true);
-  assertEquals(bool("abc"), true);
+  expect(bool("")).toBe(false);
+  expect(bool(" ")).toBe(true);
+  expect(bool("abc")).toBe(true);
 
-  assertEquals(bool([]), false);
-  assertEquals(bool([0]), true);
-  assertEquals(bool([1, 2, 3]), true);
+  expect(bool([])).toBe(false);
+  expect(bool([0])).toBe(true);
+  expect(bool([1, 2, 3])).toBe(true);
 
-  assertEquals(bool(new Set()), false);
-  assertEquals(bool(new Set([0])), true);
-  assertEquals(bool(new Set([1, 2, 3])), true);
+  expect(bool(new Set())).toBe(false);
+  expect(bool(new Set([0]))).toBe(true);
+  expect(bool(new Set([1, 2, 3]))).toBe(true);
 
-  assertEquals(bool({}), false);
-  assertEquals(bool({ a: 5 }), true);
+  expect(bool({})).toBe(false);
+  expect(bool({ a: 5 })).toBe(true);
 
   class Obj1 {}
   class Obj2 {
     private x = 0;
   }
-  assertEquals(bool(new Obj1()), false);
-  assertEquals(bool(new Obj2()), true);
+  expect(bool(new Obj1())).toBe(false);
+  expect(bool(new Obj2())).toBe(true);
 });
diff --git a/composition.test.ts b/composition.test.ts
index 4727a4f..a84b0e1 100644
--- a/composition.test.ts
+++ b/composition.test.ts
@@ -1,30 +1,30 @@
-import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { identity, nop, partial, pipe } from "./composition.ts";
 
-Deno.test("nop", () => {
-  assertEquals(nop(), undefined);
+test("nop", () => {
+  expect(nop()).toBeUndefined();
 });
 
-Deno.test("identity", () => {
-  assertEquals(identity(5), 5);
-  assertEquals(identity(null), null);
+test("identity", () => {
+  expect(identity(5)).toBe(5);
+  expect(identity(null)).toBe(null);
 });
 
-Deno.test("partial", () => {
+test("partial", () => {
   const func1 = (conf: { a: number; b: string; c: number }) =>
     `${conf.a}${conf.b}${conf.c}`;
   const pfunc1 = partial({ b: "test" }, func1);
-  assertEquals(pfunc1({ a: 5, c: 8 }), "5test8");
+  expect(pfunc1({ a: 5, c: 8 })).toEqual("5test8");
 
   const func2 = (conf: { a: number; b: string }, c: number) =>
     `${conf.a}${conf.b}${c}`;
   const pfunc2 = partial({ b: "test" }, func2);
-  assertEquals(pfunc2({ a: 2 }, 3), "2test3");
+  expect(pfunc2({ a: 2 }, 3)).toEqual("2test3");
 });
 
-Deno.test("pipe", () => {
+test("pipe", () => {
   const f = pipe((x: number) => x * 2, (x: number) => x + 1);
-  assertEquals(f(1), 3);
-  assertEquals(f(2), 5);
-  assertEquals(f(3), 7);
+  expect(f(1)).toBe(3);
+  expect(f(2)).toBe(5);
+  expect(f(3)).toBe(7);
 });
diff --git a/deps.test.ts b/deps.test.ts
new file mode 100644
index 0000000..727ba43
--- /dev/null
+++ b/deps.test.ts
@@ -0,0 +1 @@
+export * from "https://code.thunderk.net/typescript/deno_tools/raw/1.0.0/testing.ts";
diff --git a/iterables.test.ts b/iterables.test.ts
index 8bed460..5ec7cdf 100644
--- a/iterables.test.ts
+++ b/iterables.test.ts
@@ -1,47 +1,46 @@
-import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { at, first, fmap, last, second, third } from "./iterables.ts";
 
-Deno.test("at", () => {
+test("at", () => {
   const second = at(1);
-  assertEquals(second([1, 4, 8]), 4);
-  assertEquals(second([1]), undefined);
+  expect(second([1, 4, 8])).toBe(4);
+  expect(second([1])).toBeUndefined();
 
   const second_from_end = at(-2);
-  assertEquals(second_from_end([1, 4, 6, 8]), 6);
-  assertEquals(second_from_end([1]), undefined);
+  expect(second_from_end([1, 4, 6, 8])).toBe(6);
+  expect(second_from_end([1])).toBeUndefined();
 });
 
-Deno.test("first", () => {
-  assertEquals(first([1, 4, 8]), 1);
-  assertEquals(first([1]), 1);
-  assertEquals(first([]), undefined);
+test("first", () => {
+  expect(first([1, 4, 8])).toBe(1);
+  expect(first([1])).toBe(1);
+  expect(first([])).toBeUndefined();
 });
 
-Deno.test("second", () => {
-  assertEquals(second([1, 4, 8]), 4);
-  assertEquals(second([1]), undefined);
-  assertEquals(second([]), undefined);
+test("second", () => {
+  expect(second([1, 4, 8])).toBe(4);
+  expect(second([1])).toBeUndefined();
+  expect(second([])).toBeUndefined();
 });
 
-Deno.test("third", () => {
-  assertEquals(third([1, 4, 8]), 8);
-  assertEquals(third([1, 4]), undefined);
-  assertEquals(third([]), undefined);
+test("third", () => {
+  expect(third([1, 4, 8])).toBe(8);
+  expect(third([1, 4])).toBeUndefined();
+  expect(third([])).toBeUndefined();
 });
 
-Deno.test("last", () => {
-  assertEquals(last([1, 4, 8]), 8);
-  assertEquals(last([1]), 1);
-  assertEquals(last([]), undefined);
+test("last", () => {
+  expect(last([1, 4, 8])).toBe(8);
+  expect(last([1])).toBe(1);
+  expect(last([])).toBeUndefined();
 });
 
-Deno.test("fmap", () => {
-  assertEquals(fmap()([1, 2, 3]), [1, 2, 3]);
-  assertEquals(fmap((x: number) => x * 2)([1, 2, 3]), [2, 4, 6]);
-  assertEquals(fmap(undefined, (x: number) => x % 2 == 0)([1, 2, 3]), [2]);
-  assertEquals(fmap((x: number) => x * 2)([1, 2, 3]), [2, 4, 6]);
-  assertEquals(
-    fmap((x: number) => x * 2, (x: number) => x < 5)([1, 2, 3]),
+test("fmap", () => {
+  expect(fmap()([1, 2, 3])).toEqual([1, 2, 3]);
+  expect(fmap((x: number) => x * 2)([1, 2, 3])).toEqual([2, 4, 6]);
+  expect(fmap(undefined, (x: number) => x % 2 == 0)([1, 2, 3])).toEqual([2]);
+  expect(fmap((x: number) => x * 2)([1, 2, 3])).toEqual([2, 4, 6]);
+  expect(fmap((x: number) => x * 2, (x: number) => x < 5)([1, 2, 3])).toEqual(
     [2, 4],
   );
 });
diff --git a/objects.test.ts b/objects.test.ts
index ddc1d5d..6cf8217 100644
--- a/objects.test.ts
+++ b/objects.test.ts
@@ -1,8 +1,8 @@
-import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { attr } from "./objects.ts";
 
-Deno.test("attr", () => {
+test("attr", () => {
   const getx = attr("x");
-  assertEquals(getx({ x: 4, y: 5 }), 4);
-  assertEquals(getx({ x: undefined, y: 5 }), undefined);
+  expect(getx({ x: 4, y: 5 })).toBe(4);
+  expect(getx({ x: undefined, y: 5 })).toBeUndefined();
 });
diff --git a/predicates.test.ts b/predicates.test.ts
index 38401bb..2302b62 100644
--- a/predicates.test.ts
+++ b/predicates.test.ts
@@ -1,43 +1,43 @@
-import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { always, and, never, not, or } from "./predicates.ts";
 
-Deno.test("always", () => {
-  assertEquals(always(), true);
-  assertEquals(always(true), true);
-  assertEquals(always(false), true);
+test("always", () => {
+  expect(always()).toBe(true);
+  expect(always(true)).toBe(true);
+  expect(always(false)).toBe(true);
 });
 
-Deno.test("never", () => {
-  assertEquals(never(), false);
-  assertEquals(never(true), false);
-  assertEquals(never(false), false);
+test("never", () => {
+  expect(never()).toBe(false);
+  expect(never(true)).toBe(false);
+  expect(never(false)).toBe(false);
 });
 
-Deno.test("not", () => {
+test("not", () => {
   const iseven = (x: number) => x % 2 == 0;
   const isodd = not(iseven);
-  assertEquals(iseven(0), true);
-  assertEquals(isodd(0), false);
-  assertEquals(iseven(1), false);
-  assertEquals(isodd(1), true);
-  assertEquals(iseven(2), true);
-  assertEquals(isodd(2), false);
+  expect(iseven(0)).toBe(true);
+  expect(isodd(0)).toBe(false);
+  expect(iseven(1)).toBe(false);
+  expect(isodd(1)).toBe(true);
+  expect(iseven(2)).toBe(true);
+  expect(isodd(2)).toBe(false);
 });
 
-Deno.test("and", () => {
+test("and", () => {
   const f = and((x: number) => x % 2 == 0, (x: number) => x > 5);
-  assertEquals(f(0), false);
-  assertEquals(f(2), false);
-  assertEquals(f(8), true);
-  assertEquals(f(9), false);
-  assertEquals(f(10), true);
+  expect(f(0)).toBe(false);
+  expect(f(2)).toBe(false);
+  expect(f(8)).toBe(true);
+  expect(f(9)).toBe(false);
+  expect(f(10)).toBe(true);
 });
 
-Deno.test("or", () => {
+test("or", () => {
   const f = or((x: number) => x % 2 == 0, (x: number) => x > 5);
-  assertEquals(f(0), true);
-  assertEquals(f(1), false);
-  assertEquals(f(2), true);
-  assertEquals(f(8), true);
-  assertEquals(f(9), true);
+  expect(f(0)).toBe(true);
+  expect(f(1)).toBe(false);
+  expect(f(2)).toBe(true);
+  expect(f(8)).toBe(true);
+  expect(f(9)).toBe(true);
 });
diff --git a/typing.test.ts b/typing.test.ts
index 04a2fca..7121ee0 100644
--- a/typing.test.ts
+++ b/typing.test.ts
@@ -1,10 +1,7 @@
-import {
-  assertEquals,
-  assertThrows,
-} from "https://deno.land/std/testing/asserts.ts";
+import { expect, test } from "./deps.test.ts";
 import { isinstance, nn, nnu, nu } from "./typing.ts";
 
-Deno.test("isinstance", () => {
+test("isinstance", () => {
   class A {}
   class A1 extends A {}
   class A2 extends A {}
@@ -12,29 +9,29 @@ Deno.test("isinstance", () => {
 
   const f: any[] = [5, null, undefined, new A(), new A1(), new B(), new A2()];
   const result = f.filter(isinstance(A));
-  assertEquals(result, [f[3], f[4], f[6]]);
+  expect(result).toEqual([f[3], f[4], f[6]]);
 });
 
-Deno.test("nn", () => {
-  assertEquals(nn(undefined), undefined);
-  assertEquals(nn(0), 0);
-  assertEquals(nn(""), "");
-  assertEquals(nn([]), []);
-  assertThrows(() => nn(null), Error, "null value");
+test("nn", () => {
+  expect(nn(undefined)).toBeUndefined();
+  expect(nn(0)).toBe(0);
+  expect(nn("")).toBe("");
+  expect(nn([])).toEqual([]);
+  expect(() => nn(null)).toThrow("null value");
 });
 
-Deno.test("nu", () => {
-  assertEquals(nu(null), null);
-  assertEquals(nu(0), 0);
-  assertEquals(nu(""), "");
-  assertEquals(nu([]), []);
-  assertThrows(() => nu(undefined), Error, "undefined value");
+test("nu", () => {
+  expect(nu(null)).toBe(null);
+  expect(nu(0)).toBe(0);
+  expect(nu("")).toBe("");
+  expect(nu([])).toEqual([]);
+  expect(() => nu(undefined)).toThrow("undefined value");
 });
 
-Deno.test("nnu", () => {
-  assertEquals(nnu(0), 0);
-  assertEquals(nnu(""), "");
-  assertEquals(nnu([]), []);
-  assertThrows(() => nnu(undefined), Error, "undefined value");
-  assertThrows(() => nnu(null), Error, "null value");
+test("nnu", () => {
+  expect(nnu(0)).toBe(0);
+  expect(nnu("")).toBe("");
+  expect(nnu([])).toEqual([]);
+  expect(() => nnu(undefined)).toThrow("undefined value");
+  expect(() => nnu(null)).toThrow("null value");
 });