diff --git a/.gitignore b/.gitignore
index 584e45b..9817db1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .vscode
+!.vscode/launch.json
 
 # Logs
 logs
@@ -37,3 +38,10 @@ jspm_packages
 
 # Optional REPL history
 .node_repl_history
+
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+*.code-workspace
diff --git a/README.md b/README.md
index fdcd9c1..00f2303 100644
--- a/README.md
+++ b/README.md
@@ -64,4 +64,25 @@ Use build in `__proto__` property as return value.
 - If you need new folders, add the folder to the top of `./bin/concat.js` into the `folders` array
 
 
-
+## Tests
+
+To run and write tests in VSCode you'll need this `.vscode/launch.json` file
+
+```json
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+
+    {
+      "type": "extendscript-debug",
+      "request": "launch",
+      "name": "tests",
+      "program": "${workspaceFolder}/__tests__/manual.js",
+      "stopOnEntry": false
+    }
+  ]
+}
+```
diff --git a/__tests__/assertion_tests.js b/__tests__/assertion_tests.js
new file mode 100644
index 0000000..aebfac5
--- /dev/null
+++ b/__tests__/assertion_tests.js
@@ -0,0 +1,10 @@
+// @target indesign
+// @include ./assertions.js
+
+describe("Testing test functions", function() {
+  test("toBe", function() {
+    expect(1).toBe(1);
+    expect(true).toBe(true);
+    expect("foo").toBe("foo");
+  });
+});
diff --git a/__tests__/assertions.js b/__tests__/assertions.js
new file mode 100644
index 0000000..c6608fd
--- /dev/null
+++ b/__tests__/assertions.js
@@ -0,0 +1,57 @@
+/* globals $ */
+
+function describe(description, descCB) {
+  if ($.writeln !== undefined) {
+    $.writeln(description);
+  }
+  descCB();
+}
+
+function test(description, testCB) {
+  try {
+    testCB();
+    if ($.writeln !== undefined) {
+      $.writeln("✓ " + description);
+    }
+  } catch (error) {
+    if ($.writeln !== undefined) {
+      $.writeln("✘ " + description);
+      $.writeln(error);
+    }
+  }
+}
+
+function expect(actual) {
+  return {
+    toBe: function(expected) {
+      if (actual !== expected) {
+        throw new Error(actual + " is not equal to " + expected);
+      }
+    },
+    toEqual: function(expected) {
+      if (actual !== expected) {
+        throw new Error(actual + " is not equal to " + expected);
+      }
+    },
+    toEqualArray: function(expected) {
+      if (Array.isArray(actual)) {
+        for(var i = 0; i < actual.length; ++i) {
+          if (actual[i] !== expected[i])
+            throw new Error(actual + " is not equal to " + expected);
+        }
+      } else {
+        throw new Error(actual + " is not equal to " + expected);
+      }
+    },
+    toBeGreaterThen: function(expected) {
+      if (actual <= expected) {
+        throw new Error(actual + " is not greater then " + expected);
+      }
+    },
+    toBeLessThen: function(expected) {
+      if (actual >= expected) {
+        throw new Error(actual + " is not less then " + expected);
+      }
+    }
+  };
+}
diff --git a/__tests__/manual.js b/__tests__/manual.js
new file mode 100644
index 0000000..62407b8
--- /dev/null
+++ b/__tests__/manual.js
@@ -0,0 +1,87 @@
+// @target indesign
+// @include ./assertions.js
+// @include ../index.js
+
+describe("Array functions", function() {
+  
+  // array.every
+  test("array every element of [1,2,3] should be smaller then 4", function() {
+    const arr = [1, 2, 3];
+    expect(
+      arr.every(function(ele) {
+        return ele < 4;
+      })
+    ).toBe(true);
+  });
+
+  // array.filter
+  test("array filter (x<3) of [1, 2, 3, 4] should return [1, 2]", function() {
+    const arr = [1, 2, 3, 4];
+    expect(
+      arr.filter(function(ele) {
+        return ele < 3 ? true : false;
+      })
+    ).toEqualArray([1,2]);
+  });
+
+  // array.forEach
+  test("array forEach (val + 1) of [1, 2, 3] should return [2, 3, 4]", function() {
+    const arr = [1, 2, 3];
+    const newArr = [];
+    
+    arr.forEach(function(ele) {
+       newArr.push(ele + 1)
+    });
+
+    expect(newArr).toEqualArray([2, 3, 4]);
+  });
+
+  // array.indexOf
+  test("array indexOf (4) in [1, 2, 3, 4, 5, 6] should return 3", function() {
+    const arr = [1, 2, 3, 4, 5, 6];
+    expect(arr.indexOf(4)).toBe(3);
+  });
+
+  // array.isArray
+  test('array isArray on [1,2,3], should return true\n\tarray isArray on 1 should return false', function() {
+    const arr = [1,2,3];
+    expect(Array.isArray(arr)).toBe(true);
+    expect(Array.isArray(1)).toBe(false);
+  });
+
+  // array.lastIndexOf
+  test('array lastIndexOf(4) on [4, 1, 2, 3, 4] should return 4', function() {
+    const arr = [4, 1, 2, 3, 4];
+    expect(arr.lastIndexOf(4)).toBe(4);
+  });
+
+  // array.map
+  test('array map (val * 2) on [4, 1, 2, 3, 4] should return [8, 2, 4, 6, 8]', function() {
+    const arr = [4, 1, 2, 3, 4];
+    expect(arr.map(function(x) {return x * 2})).toEqualArray([8, 2, 4, 6, 8]);
+  });
+
+  // array.reduce
+  test('array reduce (sum) on [1, 2, 3, 4, 5] should return 15', function() {
+    const arr = [1, 2, 3, 4, 5];
+    expect(arr.reduce(function(acc, val) { return acc += val},0)).toBe(15);
+  });
+
+  // array.reduceRight
+  test('array reduceRight on [1, 2, 3, 4, 5] should return 15, and index should iterate this way [4, 3, 2, 1, 0]', function(){
+    const arr = [1, 2, 3, 4, 5];
+    const indexArr = [];
+    const sum = arr.reduceRight(function(acc, val, index) {
+      indexArr.push(index);
+      return acc += val;
+    }, 0);
+    expect(sum).toBe(15);
+    expect(indexArr).toEqualArray([4, 3, 2, 1, 0]);
+  });
+
+  // array.some
+  test('array some (val % 2 === 0) should return true', function() {
+    const arr = [1, 2, 3, 4, 5];
+    expect(arr.some(function(val) {return val % 2 === 0})).toBe(true);
+  });
+});
diff --git a/jest.config.js b/jest.config.js
index 2289901..d144b2d 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -2,6 +2,7 @@ module.exports = {
   testEnvironment: "jest-environment-node",
   collectCoverage: true,
   coverageReporters: ["lcov", "text"],
+  testPathIgnorePatterns: ["<rootDir>/__tests__/assertions.js"],
   collectCoverageFrom: [
     "Array/**/*.{js}",
     "Date/**/*.{js}",
diff --git a/jsconfig.json b/jsconfig.json
new file mode 100644
index 0000000..db015a7
--- /dev/null
+++ b/jsconfig.json
@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "module": "none",
+    "target": "es3"
+  },
+  "exclude": ["node_modules", "__tests__"]
+}
\ No newline at end of file