diff --git a/.github/workflows/appium.yml b/.github/workflows/appium.yml
index ae181295c..59845be91 100644
--- a/.github/workflows/appium.yml
+++ b/.github/workflows/appium.yml
@@ -4,9 +4,6 @@ on:
   push:
     branches:
       - master
-  pull_request:
-    branches:
-      - '**'
 
 env:
   CI: true
diff --git a/.github/workflows/dtslint.yml b/.github/workflows/dtslint.yml
new file mode 100644
index 000000000..c6fcc882a
--- /dev/null
+++ b/.github/workflows/dtslint.yml
@@ -0,0 +1,25 @@
+name: Typings tests
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  test:
+    runs-on: ubuntu-18.04
+    strategy:
+      matrix:
+        node-version: [12.x]
+    steps:
+    - uses: actions/checkout@v1
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm run def
+    - run: npm run dtslint
diff --git a/docs/webapi/clearField.mustache b/docs/webapi/clearField.mustache
index 26d46f1ec..afebc044c 100644
--- a/docs/webapi/clearField.mustache
+++ b/docs/webapi/clearField.mustache
@@ -5,4 +5,4 @@ I.clearField('Email');
 I.clearField('user[email]');
 I.clearField('#email');
 ```
-@param {string|object} editable field located by label|name|CSS|XPath|strict locator.
\ No newline at end of file
+@param {LocatorOrString} editable field located by label|name|CSS|XPath|strict locator.
diff --git a/docs/webapi/closeCurrentTab.mustache b/docs/webapi/closeCurrentTab.mustache
new file mode 100644
index 000000000..030ed99e8
--- /dev/null
+++ b/docs/webapi/closeCurrentTab.mustache
@@ -0,0 +1,5 @@
+ Close current tab.
+
+ ```js
+ I.closeCurrentTab();
+ ```
diff --git a/docs/webapi/closeOtherTabs.mustache b/docs/webapi/closeOtherTabs.mustache
new file mode 100644
index 000000000..68d03c036
--- /dev/null
+++ b/docs/webapi/closeOtherTabs.mustache
@@ -0,0 +1,6 @@
+ Close all tabs except for the current one.
+
+
+ ```js
+ I.closeOtherTabs();
+ ```
diff --git a/docs/webapi/dragAndDrop.mustache b/docs/webapi/dragAndDrop.mustache
index f8a84784d..59a3f2f55 100644
--- a/docs/webapi/dragAndDrop.mustache
+++ b/docs/webapi/dragAndDrop.mustache
@@ -4,5 +4,5 @@ Drag an item to a destination element.
 I.dragAndDrop('#dragHandle', '#container');
 ```
 
-@param {string|object} srcElement located by CSS|XPath|strict locator.
-@param {string|object} destElement located by CSS|XPath|strict locator.
\ No newline at end of file
+@param {LocatorOrString} srcElement located by CSS|XPath|strict locator.
+@param {LocatorOrString} destElement located by CSS|XPath|strict locator.
diff --git a/docs/webapi/grabAllWindowHandles.mustache b/docs/webapi/grabAllWindowHandles.mustache
new file mode 100644
index 000000000..fdc86db55
--- /dev/null
+++ b/docs/webapi/grabAllWindowHandles.mustache
@@ -0,0 +1,7 @@
+Get all Window Handles.
+Useful for referencing a specific handle when calling `I.switchToWindow(handle)`
+
+```js
+const windows = await I.grabAllWindowHandles();
+```
+@returns {Promise<string[]>}
diff --git a/docs/webapi/grabBrowserLogs.mustache b/docs/webapi/grabBrowserLogs.mustache
index 436d44bf9..f504f2357 100644
--- a/docs/webapi/grabBrowserLogs.mustache
+++ b/docs/webapi/grabBrowserLogs.mustache
@@ -6,4 +6,4 @@ let logs = await I.grabBrowserLogs();
 console.log(JSON.stringify(logs))
 ```
 
-@returns {Promise<Array<*>>} all browser logs
\ No newline at end of file
+@returns {Promise<object[]>|undefined} all browser logs
diff --git a/docs/webapi/grabCookie.mustache b/docs/webapi/grabCookie.mustache
index a16ce54a9..730e609bd 100644
--- a/docs/webapi/grabCookie.mustache
+++ b/docs/webapi/grabCookie.mustache
@@ -8,4 +8,4 @@ assert(cookie.value, '123456');
 ```
 
 @param {?string} [name=null] cookie name.
-@returns {Promise<string>} attribute value
\ No newline at end of file
+@returns {Promise<string>|Promise<string[]>} attribute value
diff --git a/docs/webapi/grabCurrentWindowHandle.mustache b/docs/webapi/grabCurrentWindowHandle.mustache
new file mode 100644
index 000000000..b2ff9d489
--- /dev/null
+++ b/docs/webapi/grabCurrentWindowHandle.mustache
@@ -0,0 +1,6 @@
+Get the current Window Handle.
+Useful for referencing it when calling `I.switchToWindow(handle)`
+```js
+const window = await I.grabCurrentWindowHandle();
+```
+@returns {Promise<string>}
diff --git a/docs/webapi/grabElementBoundingRect.mustache b/docs/webapi/grabElementBoundingRect.mustache
index 2b3bb851c..8d4d28d5b 100644
--- a/docs/webapi/grabElementBoundingRect.mustache
+++ b/docs/webapi/grabElementBoundingRect.mustache
@@ -15,6 +15,6 @@ To get only one metric use second parameter:
 const width = await I.grabElementBoundingRect('h3', 'width');
 // width == 527
 ```
-@param {string|object} locator element located by CSS|XPath|strict locator.
-@param {string} elementSize x, y, width or height of the given element.
-@returns {object} Element bounding rectangle
\ No newline at end of file
+@param {LocatorOrString} locator element located by CSS|XPath|strict locator.
+@param {string=} elementSize x, y, width or height of the given element.
+@returns {Promise<DOMRect>|Promise<number>} Element bounding rectangle
diff --git a/docs/webapi/grabNumberOfOpenTabs.mustache b/docs/webapi/grabNumberOfOpenTabs.mustache
index 14531fc4d..075f2b2ac 100644
--- a/docs/webapi/grabNumberOfOpenTabs.mustache
+++ b/docs/webapi/grabNumberOfOpenTabs.mustache
@@ -5,4 +5,4 @@ Resumes test execution, so **should be used inside async function with `await`**
 let tabs = await I.grabNumberOfOpenTabs();
 ```
 
-@returns {Promise<number>} number of open tabs
\ No newline at end of file
+@returns {Promise<number>} number of open tabs
diff --git a/docs/webapi/grabPageScrollPosition.mustache b/docs/webapi/grabPageScrollPosition.mustache
index b34b006d6..b6a2311d1 100644
--- a/docs/webapi/grabPageScrollPosition.mustache
+++ b/docs/webapi/grabPageScrollPosition.mustache
@@ -5,4 +5,4 @@ Resumes test execution, so **should be used inside an async function with `await
 let { x, y } = await I.grabPageScrollPosition();
 ```
 
-@returns {Promise<Object<string, *>>} scroll position
\ No newline at end of file
+@returns {Promise<PageScrollPosition>} scroll position
diff --git a/docs/webapi/grabPopupText.mustache b/docs/webapi/grabPopupText.mustache
new file mode 100644
index 000000000..964b49218
--- /dev/null
+++ b/docs/webapi/grabPopupText.mustache
@@ -0,0 +1,5 @@
+Grab the text within the popup. If no popup is visible then it will return null.
+```js
+await I.grabPopupText();
+```
+@returns {Promise<string>}
diff --git a/docs/webapi/openNewTab.mustache b/docs/webapi/openNewTab.mustache
new file mode 100644
index 000000000..a81321ea2
--- /dev/null
+++ b/docs/webapi/openNewTab.mustache
@@ -0,0 +1,5 @@
+ Open new tab and switch to it.
+
+ ```js
+ I.openNewTab();
+ ```
diff --git a/docs/webapi/scrollIntoView.mustache b/docs/webapi/scrollIntoView.mustache
index 930bf77d0..2a0e445a8 100644
--- a/docs/webapi/scrollIntoView.mustache
+++ b/docs/webapi/scrollIntoView.mustache
@@ -6,5 +6,5 @@ I.scrollIntoView('#submit', true);
 I.scrollIntoView('#submit', { behavior: "smooth", block: "center", inline: "center" });
 ```
 
-@param {string|object} locator located by CSS|XPath|strict locator.
-@param {boolean|object} alignToTop (optional) or scrollIntoViewOptions (optional), see https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView.
+@param {LocatorOrString} locator located by CSS|XPath|strict locator.
+@param {ScrollIntoViewOptions} scrollIntoViewOptions see https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView.
diff --git a/docs/webapi/seeTitleEquals.mustache b/docs/webapi/seeTitleEquals.mustache
new file mode 100644
index 000000000..9d157cb32
--- /dev/null
+++ b/docs/webapi/seeTitleEquals.mustache
@@ -0,0 +1,7 @@
+ Checks that title is equal to provided one.
+
+ ```js
+ I.seeTitleEquals('Test title.');
+ ```
+
+ @param {string} text value to check.
diff --git a/docs/webapi/selectOption.mustache b/docs/webapi/selectOption.mustache
index efa2e6b32..764dd8e44 100644
--- a/docs/webapi/selectOption.mustache
+++ b/docs/webapi/selectOption.mustache
@@ -16,5 +16,5 @@ Provide an array for the second argument to select multiple options.
 ```js
 I.selectOption('Which OS do you use?', ['Android', 'iOS']);
 ```
-@param {CodeceptJS.LocatorOrString} select field located by label|name|CSS|XPath|strict locator.
-@param {string|Array<*>} option visible text or value of option.
\ No newline at end of file
+@param {LocatorOrString} select field located by label|name|CSS|XPath|strict locator.
+@param {string|Array<*>} option visible text or value of option.
diff --git a/docs/webapi/setCookie.mustache b/docs/webapi/setCookie.mustache
index c792d8c1b..71add5d9e 100644
--- a/docs/webapi/setCookie.mustache
+++ b/docs/webapi/setCookie.mustache
@@ -12,4 +12,4 @@ I.setCookie([
 ]);
 ```
 
-@param {object|array} cookie a cookie object or array of cookie objects.
\ No newline at end of file
+@param {Cookie|Array<Cookie>} cookie a cookie object or array of cookie objects.
diff --git a/docs/webapi/setGeoLocation.mustache b/docs/webapi/setGeoLocation.mustache
index ab55fdeb0..ce45fd76d 100644
--- a/docs/webapi/setGeoLocation.mustache
+++ b/docs/webapi/setGeoLocation.mustache
@@ -8,4 +8,4 @@ I.setGeoLocation(121.21, 11.56, 10);
 
 @param {number} latitude to set.
 @param {number} longitude to set
-@param {number} altitude (optional, null by default) to set
\ No newline at end of file
+@param {number=} altitude (optional, null by default) to set
diff --git a/docs/webapi/switchToNextTab.mustache b/docs/webapi/switchToNextTab.mustache
new file mode 100644
index 000000000..114a8c32f
--- /dev/null
+++ b/docs/webapi/switchToNextTab.mustache
@@ -0,0 +1,9 @@
+ Switch focus to a particular tab by its number. It waits tabs loading and then switch tab.
+
+ ```js
+ I.switchToNextTab();
+ I.switchToNextTab(2);
+ ```
+
+ @param {number} [num] (optional) number of tabs to switch forward, default: 1.
+ @param {number | null} [sec] (optional) time in seconds to wait.
diff --git a/docs/webapi/switchToPreviousTab.mustache b/docs/webapi/switchToPreviousTab.mustache
new file mode 100644
index 000000000..4d9044114
--- /dev/null
+++ b/docs/webapi/switchToPreviousTab.mustache
@@ -0,0 +1,9 @@
+ Switch focus to a particular tab by its number. It waits tabs loading and then switch tab.
+
+ ```js
+ I.switchToPreviousTab();
+ I.switchToPreviousTab(2);
+ ```
+
+ @param {number} [num] (optional) number of tabs to switch backward, default: 1.
+ @param {number?} [sec] (optional) time in seconds to wait.
diff --git a/docs/webapi/waitForValue.mustache b/docs/webapi/waitForValue.mustache
index e3c330900..0e9f8a621 100644
--- a/docs/webapi/waitForValue.mustache
+++ b/docs/webapi/waitForValue.mustache
@@ -4,6 +4,6 @@ Waits for the specified value to be in value attribute.
 I.waitForValue('//input', "GoodValue");
 ```
 
-@param {string|object} field input field.
+@param {LocatorOrString} field input field.
 @param {string }value expected value.
-@param {number} [sec=1] (optional, `1` by default) time in seconds to wait
\ No newline at end of file
+@param {number} [sec=1] (optional, `1` by default) time in seconds to wait
diff --git a/lib/command/definitions.js b/lib/command/definitions.js
index b219009eb..458c2d569 100644
--- a/lib/command/definitions.js
+++ b/lib/command/definitions.js
@@ -48,12 +48,12 @@ module.exports = function (genPath, options) {
       helperPaths[name] = require;
       helperNames.push(name);
     } else {
-      helperNames.push(`CodeceptJS.${name}`);
+      helperNames.push(name);
     }
   }
 
   const supportObject = new Map();
-  supportObject.set('I', 'CodeceptJS.I');
+  supportObject.set('I', 'I');
   for (const name in codecept.config.include) {
     const includePath = codecept.config.include[name];
     if (name === 'I' || name === translations.I) {
diff --git a/lib/helper/WebDriver.js b/lib/helper/WebDriver.js
index 8a0030853..5081084a7 100644
--- a/lib/helper/WebDriver.js
+++ b/lib/helper/WebDriver.js
@@ -1194,7 +1194,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> seeInTitle }}
-   *
    */
   async seeInTitle(text) {
     const title = await this.browser.getTitle();
@@ -1202,13 +1201,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Checks that title is equal to provided one.
-   *
-   * ```js
-   * I.seeTitleEquals('Test title.');
-   * ```
-   *
-   * @param {string} text value to check.
+   * {{> seeTitleEquals }}
    */
   async seeTitleEquals(text) {
     const title = await this.browser.getTitle();
@@ -1217,7 +1210,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> dontSeeInTitle }}
-   *
    */
   async dontSeeInTitle(text) {
     const title = await this.browser.getTitle();
@@ -1226,7 +1218,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> grabTitle }}
-   *
    */
   async grabTitle() {
     const title = await this.browser.getTitle();
@@ -1352,13 +1343,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Get JS log from browser. Log buffer is reset after each request.
-   *
-   * ```js
-   * let logs = await I.grabBrowserLogs();
-   * console.log(JSON.stringify(logs))
-   * ```
-   * @returns {Promise<string|undefined>}
+   * {{> grabBrowserLogs }}
    */
   async grabBrowserLogs() {
     if (this.browser.isW3C) {
@@ -1575,7 +1560,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> moveCursorTo }}
-   *
    */
   async moveCursorTo(locator, xOffset, yOffset) {
     const res = await this._locate(withStrictLocator(locator), true);
@@ -1587,7 +1571,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> saveScreenshot }}
-   *
    */
   async saveScreenshot(fileName, fullPage = false) {
     const outputFile = screenshotOutputFolder(fileName);
@@ -1639,7 +1622,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> clearCookie }}
-   *
    */
   async clearCookie(cookie) {
     return this.browser.deleteCookies(cookie);
@@ -1647,7 +1629,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> seeCookie }}
-   *
    */
   async seeCookie(name) {
     const cookie = await this.browser.getCookies([name]);
@@ -1656,7 +1637,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> dontSeeCookie }}
-   *
    */
   async dontSeeCookie(name) {
     const cookie = await this.browser.getCookies([name]);
@@ -1665,7 +1645,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> grabCookie }}
-   *
    */
   async grabCookie(name) {
     if (!name) return this.browser.getCookies();
@@ -1715,11 +1694,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Grab the text within the popup. If no popup is visible then it will return null.
-   *
-   * ```js
-   * await I.grabPopupText();
-   * ```
+   * {{> grabPopupText }}
    */
   async grabPopupText() {
     try {
@@ -1889,24 +1864,14 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Get all Window Handles.
-   * Useful for referencing a specific handle when calling `I.switchToWindow(handle)`
-   *
-   * ```js
-   * const windows = await I.grabAllWindowHandles();
-   * ```
+   * {{> grabAllWindowHandles }}
    */
   async grabAllWindowHandles() {
     return this.browser.getWindowHandles();
   }
 
   /**
-   * Get the current Window Handle.
-   * Useful for referencing it when calling `I.switchToWindow(handle)`
-   *
-   * ```js
-   * const window = await I.grabCurrentWindowHandle();
-   * ```
+   * {{> grabCurrentWindowHandle }}
    */
   async grabCurrentWindowHandle() {
     return this.browser.getWindowHandle();
@@ -1924,18 +1889,14 @@ class WebDriver extends Helper {
    * // ... do something
    * await I.switchToWindow( window );
    * ```
+   * @param {string} window name of window handle.
    */
   async switchToWindow(window) {
     await this.browser.switchToWindow(window);
   }
 
   /**
-   * Close all tabs except for the current one.
-   *
-   *
-   * ```js
-   * I.closeOtherTabs();
-   * ```
+   * {{> closeOtherTabs }}
    */
   async closeOtherTabs() {
     const handles = await this.browser.getWindowHandles();
@@ -1951,7 +1912,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> wait }}
-   *
    */
   async wait(sec) {
     return new Promise(resolve => setTimeout(resolve, sec * 1000));
@@ -1959,7 +1919,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> waitForEnabled }}
-   *
    */
   async waitForEnabled(locator, sec = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2024,13 +1983,6 @@ class WebDriver extends Helper {
     });
   }
 
-  async waitUntilExists(locator, sec = null) {
-    console.log(`waitUntilExists deprecated:
-    * use 'waitForElement' to wait for element to be attached
-    * use 'waitForDetached to wait for element to be removed'`);
-    return this.waitForStalenessOf(locator, sec);
-  }
-
   /**
    * {{> waitInUrl }}
    */
@@ -2220,7 +2172,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> waitForInvisible }}
-   *
    */
   async waitForInvisible(locator, sec = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2242,20 +2193,13 @@ class WebDriver extends Helper {
 
   /**
    * {{> waitToHide }}
-   *
    */
   async waitToHide(locator, sec = null) {
     return this.waitForInvisible(locator, sec);
   }
 
-  async waitForStalenessOf(locator, sec = null) {
-    console.log('waitForStalenessOf deprecated. Use waitForDetached instead');
-    return this.waitForDetached(locator, sec);
-  }
-
   /**
    * {{> waitForDetached }}
-   *
    */
   async waitForDetached(locator, sec = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2279,7 +2223,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> waitForFunction }}
-   *
    */
   async waitForFunction(fn, argsOrSec = null, sec = null) {
     let args = [];
@@ -2300,7 +2243,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> waitUntil }}
-   *
    */
   async waitUntil(fn, sec = null, timeoutMsg = null, interval = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2313,7 +2255,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> switchTo }}
-   *
    */
   async switchTo(locator) {
     this.browser.isInsideFrame = true;
@@ -2331,15 +2272,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Switch focus to a particular tab by its number. It waits tabs loading and then switch tab.
-   *
-   * ```js
-   * I.switchToNextTab();
-   * I.switchToNextTab(2);
-   * ```
-   *
-   * @param {number} [num] (optional) number of tabs to switch forward, default: 1.
-   * @param {number | null} [sec] (optional) time in seconds to wait.
+   * {{> switchToNextTab }}
    */
   async switchToNextTab(num = 1, sec = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2370,15 +2303,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Switch focus to a particular tab by its number. It waits tabs loading and then switch tab.
-   *
-   * ```js
-   * I.switchToPreviousTab();
-   * I.switchToPreviousTab(2);
-   * ```
-   *
-   * @param {number} [num] (optional) number of tabs to switch backward, default: 1.
-   * @param {number?} [sec] (optional) time in seconds to wait.
+   * {{> switchToPreviousTab }}
    */
   async switchToPreviousTab(num = 1, sec = null) {
     const aSec = sec || this.options.waitForTimeout;
@@ -2409,11 +2334,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Close current tab.
-   *
-   * ```js
-   * I.closeCurrentTab();
-   * ```
+   * {{> closeCurrentTab }}
    */
   async closeCurrentTab() {
     await this.browser.closeWindow();
@@ -2422,11 +2343,7 @@ class WebDriver extends Helper {
   }
 
   /**
-   * Open new tab and switch to it.
-   *
-   * ```js
-   * I.openNewTab();
-   * ```
+   * {{> openNewTab }}
    */
   async openNewTab(url = 'about:blank', windowName = null) {
     const client = this.browser;
@@ -2500,7 +2417,6 @@ class WebDriver extends Helper {
 
   /**
    * {{> setGeoLocation }}
-   *
    */
   async setGeoLocation(latitude, longitude, altitude = null) {
     if (altitude) {
diff --git a/package.json b/package.json
index 2b1ced953..63700fa13 100644
--- a/package.json
+++ b/package.json
@@ -23,10 +23,10 @@
   },
   "files": [
     "bin",
-    "docs",
+    "docs/**/*.md",
     "lib",
     "translations",
-    "typings"
+    "typings/**/*.d.ts"
   ],
   "main": "lib/index.js",
   "typings": "typings/index.d.ts",
@@ -49,7 +49,8 @@
     "def": "./runio.js def",
     "dev:graphql": "nodemon test/data/graphql/index.js",
     "publish:site": "./runio.js publish:site",
-    "update-contributor-faces": "contributor-faces ."
+    "update-contributor-faces": "contributor-faces .",
+    "dtslint": "dtslint typings --localTs './node_modules/typescript/lib'"
   },
   "dependencies": {
     "acorn": "^7.1.0",
@@ -99,6 +100,7 @@
     "chai-as-promised": "^5.2.0",
     "chai-subset": "^1.6.0",
     "contributor-faces": "^1.0.3",
+    "dtslint": "^3.6.12",
     "documentation": "^12.3.0",
     "eslint": "^6.8.0",
     "expect": "^26.0.1",
@@ -126,13 +128,13 @@
     "sinon-chai": "^3.5.0",
     "testcafe": "^1.8.6",
     "ts-morph": "^3.1.3",
+    "typescript": "^3.7.5",
+    "xml2js": "^0.4.23",
     "tsd-jsdoc": "^2.5.0",
-    "typescript": "^2.9.2",
     "wdio-docker-service": "^1.5.0",
     "webdriverio": "^6.1.19",
     "xmldom": "^0.1.31",
-    "xpath": "0.0.27",
-    "xml2js": "^0.4.23"
+    "xpath": "0.0.27"
   },
   "engines": {
     "node": ">=8.9.1",
diff --git a/test/runner/allure_test.js b/test/runner/allure_test.js
index a65044ada..0af5d87b2 100644
--- a/test/runner/allure_test.js
+++ b/test/runner/allure_test.js
@@ -77,13 +77,13 @@ describe('CodeceptJS Allure Plugin', function () {
 
   it('should report skipped features', (done) => {
     exec(codecept_run_config('skipped_feature.conf.js'), (err, stdout) => {
-      stdout.should.include('OK  | 0 passed, 2 skipped');
+      expect(stdout).toContain('OK  | 0 passed, 2 skipped');
       const files = fs.readdirSync(path.join(codecept_dir, 'output/skipped'));
       const reports = files.map((testResultPath) => {
-        assert(testResultPath.match(/\.xml$/), 'not a xml file');
+        expect(testResultPath.match(/\.xml$/)).toBeTruthy();
         return fs.readFileSync(path.join(codecept_dir, 'output/skipped', testResultPath), 'utf8');
       }).join(' ');
-      reports.should.include('Skipped due to "skip" on Feature.');
+      expect(reports).toContain('Skipped due to "skip" on Feature.');
       done();
     });
   });
diff --git a/test/runner/definitions_test.js b/test/runner/definitions_test.js
index 0f96f484f..21ef4cfc9 100644
--- a/test/runner/definitions_test.js
+++ b/test/runner/definitions_test.js
@@ -155,7 +155,7 @@ describe('Definitions', function () {
       returned.should.containSubset([
         {
           properties: [
-            { name: 'I', type: 'CodeceptJS.I' },
+            { name: 'I', type: 'I' },
             { name: 'MyPage', type: 'MyPage' },
           ],
         },
@@ -172,7 +172,7 @@ describe('Definitions', function () {
       const definitionsFile = types.getSourceFileOrThrow(pathOfStaticDefinitions);
       const returned = getReturnStructure(definitionsFile.getFunctionOrThrow('inject'));
       returned.should.containSubset([{
-        properties: [{ name: 'I', type: 'CodeceptJS.I' }],
+        properties: [{ name: 'I', type: 'I' }],
       }]);
       done();
     });
@@ -186,7 +186,7 @@ describe('Definitions', function () {
       const definitionsFile = types.getSourceFileOrThrow(`${codecept_dir}/steps.d.ts`);
       const CallbackOrder = definitionsFile.getNamespaceOrThrow('CodeceptJS').getInterfaceOrThrow('SupportObject').getStructure();
       CallbackOrder.properties.should.containSubset([
-        { name: 'I', type: 'CodeceptJS.I' },
+        { name: 'I', type: 'I' },
         { name: 'MyPage', type: 'MyPage' },
         { name: 'SecondPage', type: 'SecondPage' },
       ]);
diff --git a/test/runner/dry_run_test.js b/test/runner/dry_run_test.js
index 03a46650d..59cdbf990 100644
--- a/test/runner/dry_run_test.js
+++ b/test/runner/dry_run_test.js
@@ -5,7 +5,7 @@ const exec = require('child_process').exec;
 const runner = path.join(__dirname, '/../../bin/codecept.js');
 const codecept_dir = path.join(__dirname, '/../data/sandbox');
 const codecept_run = `${runner} dry-run`;
-const codecept_run_config = config => `${codecept_run} --config ${codecept_dir}/${config}`;
+const codecept_run_config = (config, grep) => `${codecept_run} --config ${codecept_dir}/${config} ${grep ? `--grep "${grep}"` : ''}`;
 const char = require('figures').checkboxOff;
 
 describe('dry-run command', () => {
@@ -159,7 +159,7 @@ describe('dry-run command', () => {
   });
 
   it('should work with inject() keyword', (done) => {
-    exec(`${codecept_run_config('configs/pageObjects/codecept.inject.po.json')} --debug`, (err, stdout) => {
+    exec(`${codecept_run_config('configs/pageObjects/codecept.inject.po.json', 'check current dir')} --debug`, (err, stdout) => {
       const lines = stdout.split('\n');
       expect(stdout).toContain('injected');
       expect(lines).toEqual(
diff --git a/tsconfig.json b/tsconfig.json
index b7c3edd1f..15445914a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -16,5 +16,8 @@
   "include": [
     "lib",
     "typings"
+  ],
+  "exclude": [
+    "typings/tests"
   ]
-}
\ No newline at end of file
+}
diff --git a/typings/Mocha.d.ts b/typings/Mocha.d.ts
index f1ea30558..cb73a2a1c 100644
--- a/typings/Mocha.d.ts
+++ b/typings/Mocha.d.ts
@@ -1,4 +1,4 @@
-declare module Mocha {
+declare namespace Mocha {
   class SuiteRunnable {
     private _beforeEach;
     private _beforeAll;
@@ -11,9 +11,9 @@ declare module Mocha {
     private _retries;
     private _onlyTests;
     private _onlySuites;
-  
+
     constructor(title: string, parentContext?: Context);
-  
+
     ctx: Context;
     suites: Suite[];
     tests: Test[];
@@ -23,7 +23,7 @@ declare module Mocha {
     delayed: boolean;
     parent: Suite | undefined;
     title: string;
-  
+
     /**
      * Create a new `Suite` with the given `title` and parent `Suite`. When a suite
      * with the same title is already present, that suite is returned to provide
@@ -32,217 +32,161 @@ declare module Mocha {
      * @see https://mochajs.org/api/mocha#.exports.create
      */
     static create(parent: Suite, title: string): Suite;
-  
+
     /**
      * Return a clone of this `Suite`.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#clone
      */
     clone(): Suite;
-  
+
     /**
      * Get timeout `ms`.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#timeout
      */
     timeout(): number;
-  
+
     /**
      * Set timeout `ms` or short-hand such as "2s".
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#timeout
      */
     timeout(ms: string | number): this;
-  
+
     /**
      * Get number of times to retry a failed test.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#retries
      */
     retries(): number;
-  
+
     /**
      * Set number of times to retry a failed test.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#retries
      */
     retries(n: string | number): this;
-  
+
     /**
      * Get whether timeouts are enabled.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#enableTimeouts
      */
     enableTimeouts(): boolean;
-  
+
     /**
      * Set whether timeouts are `enabled`.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#enableTimeouts
      */
     enableTimeouts(enabled: boolean): this;
-  
+
     /**
      * Get slow `ms`.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#slow
      */
     slow(): number;
-  
+
     /**
      * Set slow `ms` or short-hand such as "2s".
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#slow
      */
     slow(ms: string | number): this;
-  
+
     /**
      * Get whether to bail after first error.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#bail
      */
     bail(): boolean;
-  
+
     /**
      * Set whether to bail after first error.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#bail
      */
     bail(bail: boolean): this;
-  
+
     /**
      * Check if this suite or its parent suite is marked as pending.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#isPending
      */
     isPending(): boolean;
-  
-    /**
-     * Run `fn(test[, done])` before running tests.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#beforeAll
-     */
-    beforeAll(fn?: Func): this;
-  
-    /**
-     * Run `fn(test[, done])` before running tests.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#beforeAll
-     */
-    beforeAll(fn?: AsyncFunc): this;
-  
+
     /**
      * Run `fn(test[, done])` before running tests.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#beforeAll
      */
-    beforeAll(title: string, fn?: Func): this;
-  
+    beforeAll(fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` before running tests.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#beforeAll
      */
-    beforeAll(title: string, fn?: AsyncFunc): this;
-  
-    /**
-     * Run `fn(test[, done])` after running tests.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#afterAll
-     */
-    afterAll(fn?: Func): this;
-  
-    /**
-     * Run `fn(test[, done])` after running tests.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#afterAll
-     */
-    afterAll(fn?: AsyncFunc): this;
-  
+    beforeAll(title: string, fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` after running tests.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#afterAll
      */
-    afterAll(title: string, fn?: Func): this;
-  
+    afterAll(fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` after running tests.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#afterAll
      */
-    afterAll(title: string, fn?: AsyncFunc): this;
-  
-    /**
-     * Run `fn(test[, done])` before each test case.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#beforeEach
-     */
-    beforeEach(fn?: Func): this;
-  
-    /**
-     * Run `fn(test[, done])` before each test case.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#beforeEach
-     */
-    beforeEach(fn?: AsyncFunc): this;
-  
+    afterAll(title: string, fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` before each test case.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#beforeEach
      */
-    beforeEach(title: string, fn?: Func): this;
-  
+    beforeEach(fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` before each test case.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#beforeEach
      */
-    beforeEach(title: string, fn?: AsyncFunc): this;
-  
-    /**
-     * Run `fn(test[, done])` after each test case.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#afterEach
-     */
-    afterEach(fn?: Func): this;
-  
-    /**
-     * Run `fn(test[, done])` after each test case.
-     *
-     * @see https://mochajs.org/api/Mocha.Suite.html#afterEach
-     */
-    afterEach(fn?: AsyncFunc): this;
-  
+    beforeEach(title: string, fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` after each test case.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#afterEach
      */
-    afterEach(title: string, fn?: Func): this;
-  
+    afterEach(fn?: Func | AsyncFunc): this;
+
     /**
      * Run `fn(test[, done])` after each test case.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#afterEach
      */
-    afterEach(title: string, fn?: AsyncFunc): this;
-  
+    afterEach(title: string, fn?: Func | AsyncFunc): this;
+
     /**
      * Add a test `suite`.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#addSuite
      */
     addSuite(suite: Suite): this;
-  
+
     /**
      * Add a `test` to this suite.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#addTest
      */
     addTest(test: Test): this;
-  
+
     /**
      * Return the full title generated by recursively concatenating the parent's
      * full title.
@@ -250,7 +194,7 @@ declare module Mocha {
      * @see https://mochajs.org/api/Mocha.Suite.html#.Suite#fullTitle
      */
     fullTitle(): string;
-  
+
     /**
      * Return the title path generated by recursively concatenating the parent's
      * title path.
@@ -258,14 +202,14 @@ declare module Mocha {
      * @see https://mochajs.org/api/Mocha.Suite.html#.Suite#titlePath
      */
     titlePath(): string[];
-  
+
     /**
      * Return the total number of tests.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#.Suite#total
      */
     total(): number;
-  
+
     /**
      * Iterates through each suite recursively to find all tests. Applies a
      * function in the format `fn(test)`.
@@ -273,14 +217,14 @@ declare module Mocha {
      * @see https://mochajs.org/api/Mocha.Suite.html#eachTest
      */
     eachTest(fn: (test: Test) => void): this;
-  
+
     /**
      * This will run the root suite if we happen to be running in delayed mode.
      *
      * @see https://mochajs.org/api/Mocha.Suite.html#run
      */
     run(): void;
-  
+
     /**
      * Generic hook-creator.
      */
@@ -569,4 +513,4 @@ declare module Mocha {
 
       [key: string]: any;
   }
-}
\ No newline at end of file
+}
diff --git a/typings/index.d.ts b/typings/index.d.ts
index 859ab6415..9ce324515 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -1,4 +1,3 @@
-// Type definitions for CodeceptJS
 // Project: https://github.com/codeception/codeceptjs/
 /// <reference path="./types.d.ts" />
 /// <reference types="webdriverio" />
@@ -6,7 +5,17 @@
 
 declare namespace CodeceptJS {
   type WithTranslation<T> = T &
-    import("./utils").Translate<T, CodeceptJS.Translation.Actions>;
+    import("./utils").Translate<T, Translation.Actions>;
+
+  type Cookie = {
+    name: string
+    value: string
+  }
+
+  interface PageScrollPosition {
+    x: number,
+    y: number
+  }
 
   // Could get extended by user generated typings
   interface Methods extends ActorStatic {}
@@ -28,7 +37,7 @@ declare namespace CodeceptJS {
   }
 
   // Types who are not be defined by JSDoc
-  type actor = <T extends { [action: string]: Function }>(
+  type actor = <T extends { [action: string]: () => void }>(
     customSteps?: T & ThisType<WithTranslation<Methods & T>>
   ) => WithTranslation<Methods & T>;
 
@@ -46,14 +55,13 @@ declare namespace CodeceptJS {
   type LocatorOrString = string | ILocator | Locator;
 
   interface HookCallback { (args: SupportObject): void; }
-  interface Scenario extends IScenario { only: IScenario, skip: IScenario, todo:  IScenario}
+  interface Scenario extends IScenario { only: IScenario, skip: IScenario, todo: IScenario}
   interface Feature extends IFeature { skip: IFeature }
   interface IData { Scenario: IScenario, only: { Scenario: IScenario } }
 
   interface IScenario {
     // Scenario.todo can be called only with a title.
-    (title: string): ScenarioConfig;
-    (title: string, callback: HookCallback): ScenarioConfig;
+    (title: string, callback?: HookCallback): ScenarioConfig;
     (title: string, opts: { [key: string]: any }, callback: HookCallback): ScenarioConfig;
   }
   interface IHook { (callback: HookCallback): void; }
@@ -150,13 +158,13 @@ declare namespace Mocha {
     After: typeof After;
   }
 
-  interface Suite extends SuiteRunnable{
+  interface Suite extends SuiteRunnable {
     tags: any[]
     comment: string
     feature: any
   }
 
-  interface Test  extends Runnable{
+  interface Test  extends Runnable {
     tags: any[];
   }
 }
diff --git a/typings/tests/global-variables.types.ts b/typings/tests/global-variables.types.ts
new file mode 100644
index 000000000..670c0a617
--- /dev/null
+++ b/typings/tests/global-variables.types.ts
@@ -0,0 +1,50 @@
+Feature() // $ExpectError
+Scenario() // $ExpectError
+Before() // $ExpectError
+BeforeSuite() // $ExpectError
+After() // $ExpectError
+AfterSuite() // $ExpectError
+
+Feature('feature') // $ExpectType FeatureConfig
+
+Scenario('scenario') // $ExpectType ScenarioConfig
+Scenario(
+  'scenario',
+  {}, // $ExpectType {}
+  () => {} // $ExpectType () => void
+)
+Scenario(
+  'scenario',
+  () => {} // $ExpectType () => void
+)
+const callback: CodeceptJS.HookCallback = () => {}
+Scenario(
+  'scenario',
+  callback // $ExpectType HookCallback
+)
+Scenario('scenario',
+  (args) => {
+    args // $ExpectType SupportObject
+    args.I // $ExpectType I
+  }
+)
+
+Before((args) => {
+  args // $ExpectType SupportObject
+  args.I // $ExpectType I
+})
+
+BeforeSuite((args) => {
+  args // $ExpectType SupportObject
+  args.I // $ExpectType I
+})
+
+After((args) => {
+  args // $ExpectType SupportObject
+  args.I // $ExpectType I
+})
+
+AfterSuite((args) => {
+  args // $ExpectType SupportObject
+  args.I // $ExpectType I
+})
diff --git a/typings/tests/helper.types.ts b/typings/tests/helper.types.ts
new file mode 100644
index 000000000..1f02ecea7
--- /dev/null
+++ b/typings/tests/helper.types.ts
@@ -0,0 +1,46 @@
+// @TODO: Need tests arguments of protected methods
+
+class CustomClass extends Helper {
+  constructor(config: any) {
+    super(
+      config // $ExpectType any
+    )
+    this.helpers // $ExpectType any
+    this.debug() // $ExpectError
+    this.debugSection() // $ExpectError
+    this.debugSection('[Section]') // $ExpectError
+
+    this.debug('log') // $ExpectType void
+    this.debugSection('[Section]', 'log') // $ExpectType void
+  }
+  _failed() {} // $ExpectType () => void
+  _finishTest() {} // $ExpectType () => void
+  _init() {} // $ExpectType () => void
+  _passed() {} // $ExpectType () => void
+  _setConfig() {} // $ExpectType () => void
+  _useTo() {} // $ExpectType () => void
+  _validateConfig() {} // $ExpectType () => void
+  _before() {} // $ExpectType () => void
+  _beforeStep() {} // $ExpectType () => void
+  _beforeSuite() {} // $ExpectType () => void
+  _after() {} // $ExpectType () => void
+  _afterStep() {} // $ExpectType () => void
+  _afterSuite() {} // $ExpectType () => void
+}
+
+const customClass = new Helper({})
+
+customClass._failed() // $ExpectError
+customClass._finishTest() // $ExpectError
+customClass._init() // $ExpectError
+customClass._passed() // $ExpectError
+customClass._setConfig() // $ExpectError
+customClass._validateConfig() // $ExpectError
+customClass._before() // $ExpectError
+customClass._beforeStep() // $ExpectError
+customClass._beforeSuite() // $ExpectError
+customClass._after() // $ExpectError
+customClass._afterStep() // $ExpectError
+customClass._afterSuite() // $ExpectError
+
+customClass._useTo() // $ExpectType void
diff --git a/typings/tests/helpers/WebDriverIO.types.ts b/typings/tests/helpers/WebDriverIO.types.ts
new file mode 100644
index 000000000..f544d38af
--- /dev/null
+++ b/typings/tests/helpers/WebDriverIO.types.ts
@@ -0,0 +1,439 @@
+const wd = new CodeceptJS.WebDriver()
+
+const str = 'text'
+const num = 1
+
+wd.amOnPage() // $ExpectError
+wd.amOnPage('') // $ExpectType void
+
+wd.click() // $ExpectError
+wd.click('div') // $ExpectType void
+wd.click({ css: 'div' })
+wd.click({ xpath: '//div' })
+wd.click({ name: 'div' })
+wd.click({ id: 'div' })
+wd.click({ android: 'div' })
+wd.click({ ios: 'div' })
+wd.click(locate('div'))
+wd.click('div', 'body')
+wd.click('div', locate('div'))
+wd.click('div', { css: 'div' })
+wd.click('div', { xpath: '//div' })
+wd.click('div', { name: '//div' })
+wd.click('div', { id: '//div' })
+wd.click('div', { android: '//div' })
+wd.click('div', { ios: '//div' })
+
+wd.forceClick() // $ExpectError
+wd.forceClick('div') // $ExpectType void
+wd.forceClick({ css: 'div' })
+wd.forceClick({ xpath: '//div' })
+wd.forceClick({ name: 'div' })
+wd.forceClick({ id: 'div' })
+wd.forceClick({ android: 'div' })
+wd.forceClick({ ios: 'div' })
+wd.forceClick(locate('div'))
+wd.forceClick('div', 'body')
+wd.forceClick('div', locate('div'))
+wd.forceClick('div', { css: 'div' })
+wd.forceClick('div', { xpath: '//div' })
+wd.forceClick('div', { name: '//div' })
+wd.forceClick('div', { id: '//div' })
+wd.forceClick('div', { android: '//div' })
+wd.forceClick('div', { ios: '//div' })
+
+wd.doubleClick() // $ExpectError
+wd.doubleClick('div') // $ExpectType void
+wd.doubleClick({ css: 'div' })
+wd.doubleClick({ xpath: '//div' })
+wd.doubleClick({ name: 'div' })
+wd.doubleClick({ id: 'div' })
+wd.doubleClick({ android: 'div' })
+wd.doubleClick({ ios: 'div' })
+wd.doubleClick(locate('div'))
+wd.doubleClick('div', 'body')
+wd.doubleClick('div', locate('div'))
+wd.doubleClick('div', { css: 'div' })
+wd.doubleClick('div', { xpath: '//div' })
+wd.doubleClick('div', { name: '//div' })
+wd.doubleClick('div', { id: '//div' })
+wd.doubleClick('div', { android: '//div' })
+wd.doubleClick('div', { ios: '//div' })
+
+wd.rightClick() // $ExpectError
+wd.rightClick('div') // $ExpectType void
+wd.rightClick({ css: 'div' })
+wd.rightClick({ xpath: '//div' })
+wd.rightClick({ name: 'div' })
+wd.rightClick({ id: 'div' })
+wd.rightClick({ android: 'div' })
+wd.rightClick({ ios: 'div' })
+wd.rightClick(locate('div'))
+wd.rightClick('div', 'body')
+wd.rightClick('div', locate('div'))
+wd.rightClick('div', { css: 'div' })
+wd.rightClick('div', { xpath: '//div' })
+wd.rightClick('div', { name: '//div' })
+wd.rightClick('div', { id: '//div' })
+wd.rightClick('div', { android: '//div' })
+wd.rightClick('div', { ios: '//div' })
+
+wd.fillField() // $ExpectError
+wd.fillField('div') // $ExpectError
+wd.fillField('div', str) // $ExpectType void
+wd.fillField({ css: 'div' }, str)
+wd.fillField({ xpath: '//div' }, str)
+wd.fillField({ name: 'div' }, str)
+wd.fillField({ id: 'div' }, str)
+wd.fillField({ android: 'div' }, str)
+wd.fillField({ ios: 'div' }, str)
+wd.fillField(locate('div'), str)
+
+wd.appendField() // $ExpectError
+wd.appendField('div') // $ExpectError
+wd.appendField('div', str) // $ExpectType void
+wd.appendField({ css: 'div' }, str)
+wd.appendField({ xpath: '//div' }, str)
+wd.appendField({ name: 'div' }, str)
+wd.appendField({ id: 'div' }, str)
+wd.appendField({ android: 'div' }, str)
+wd.appendField({ ios: 'div' }, str)
+wd.appendField(locate('div'), str)
+
+wd.clearField() // $ExpectError
+wd.clearField('div')
+wd.clearField({ css: 'div' })
+wd.clearField({ xpath: '//div' })
+wd.clearField({ name: 'div' })
+wd.clearField({ id: 'div' })
+wd.clearField({ android: 'div' })
+wd.clearField({ ios: 'div' })
+
+wd.selectOption() // $ExpectError
+wd.selectOption('div') // $ExpectError
+wd.selectOption('div', str) // $ExpectType void
+
+wd.attachFile() // $ExpectError
+wd.attachFile('div') // $ExpectError
+wd.attachFile('div', str) // $ExpectType void
+
+wd.checkOption() // $ExpectError
+wd.checkOption('div') // $ExpectType void
+
+wd.uncheckOption() // $ExpectError
+wd.uncheckOption('div') // $ExpectType void
+
+wd.seeInTitle() // $ExpectError
+wd.seeInTitle(str) // $ExpectType void
+
+wd.seeTitleEquals() // $ExpectError
+wd.seeTitleEquals(str) // $ExpectType void
+
+wd.dontSeeInTitle() // $ExpectError
+wd.dontSeeInTitle(str) // $ExpectType void
+
+wd.see() // $ExpectError
+wd.see(str) // $ExpectType void
+wd.see(str, 'div') // $ExpectType void
+
+wd.dontSee() // $ExpectError
+wd.dontSee(str) // $ExpectType void
+wd.dontSee(str, 'div') // $ExpectType void
+
+wd.seeTextEquals() // $ExpectError
+wd.seeTextEquals(str) // $ExpectType void
+wd.seeTextEquals(str, 'div') // $ExpectType void
+
+wd.seeInField() // $ExpectError
+wd.seeInField('div') // $ExpectError
+wd.seeInField('div', str) // $ExpectType void
+
+wd.dontSeeInField() // $ExpectError
+wd.dontSeeInField('div') // $ExpectError
+wd.dontSeeInField('div', str) // $ExpectType void
+
+wd.seeCheckboxIsChecked() // $ExpectError
+wd.seeCheckboxIsChecked('div') // $ExpectType void
+
+wd.dontSeeCheckboxIsChecked() // $ExpectError
+wd.dontSeeCheckboxIsChecked('div') // $ExpectType void
+
+wd.seeElement() // $ExpectError
+wd.seeElement('div') // $ExpectType void
+
+wd.dontSeeElement() // $ExpectError
+wd.dontSeeElement('div') // $ExpectType void
+
+wd.seeElementInDOM() // $ExpectError
+wd.seeElementInDOM('div') // $ExpectType void
+
+wd.dontSeeElementInDOM() // $ExpectError
+wd.dontSeeElementInDOM('div') // $ExpectType void
+
+wd.seeInSource() // $ExpectError
+wd.seeInSource(str) // $ExpectType void
+
+wd.dontSeeInSource() // $ExpectError
+wd.dontSeeInSource(str) // $ExpectType void
+
+wd.seeNumberOfElements() // $ExpectError
+wd.seeNumberOfElements('div') // $ExpectError
+wd.seeNumberOfElements('div', num) // $ExpectType void
+
+wd.seeNumberOfVisibleElements() // $ExpectError
+wd.seeNumberOfVisibleElements('div') // $ExpectError
+wd.seeNumberOfVisibleElements('div', num) // $ExpectType void
+
+wd.seeCssPropertiesOnElements() // $ExpectError
+wd.seeCssPropertiesOnElements('div') // $ExpectError
+wd.seeCssPropertiesOnElements('div', str) // $ExpectType void
+
+wd.seeAttributesOnElements() // $ExpectError
+wd.seeAttributesOnElements('div') // $ExpectError
+wd.seeAttributesOnElements('div', str) // $ExpectType void
+
+wd.seeInCurrentUrl() // $ExpectError
+wd.seeInCurrentUrl(str) // $ExpectType void
+
+wd.seeCurrentUrlEquals() // $ExpectError
+wd.seeCurrentUrlEquals(str) // $ExpectType void
+
+wd.dontSeeInCurrentUrl() // $ExpectError
+wd.dontSeeInCurrentUrl(str) // $ExpectType void
+
+wd.dontSeeCurrentUrlEquals() // $ExpectError
+wd.dontSeeCurrentUrlEquals(str) // $ExpectType void
+
+wd.executeScript() // $ExpectError
+wd.executeScript(str) // $ExpectType Promise<any>
+wd.executeScript(() => {}) // $ExpectType Promise<any>
+wd.executeScript(() => {}, {}) // $ExpectType Promise<any>
+
+wd.executeAsyncScript() // $ExpectError
+wd.executeAsyncScript(str) // $ExpectType Promise<any>
+wd.executeAsyncScript(() => {}) // $ExpectType Promise<any>
+wd.executeAsyncScript(() => {}, {}) // $ExpectType Promise<any>
+
+wd.scrollIntoView() // $ExpectError
+wd.scrollIntoView('div') // $ExpectError
+wd.scrollIntoView('div', {behavior: "auto", block: "center", inline: "center"})
+
+wd.scrollTo() // $ExpectError
+wd.scrollTo('div') // $ExpectType void
+wd.scrollTo('div', num, num) // $ExpectType void
+
+wd.moveCursorTo() // $ExpectError
+wd.moveCursorTo('div') // $ExpectType void
+wd.moveCursorTo('div', num, num) // $ExpectType void
+
+wd.saveScreenshot() // $ExpectError
+wd.saveScreenshot(str) // $ExpectType void
+wd.saveScreenshot(str, true) // $ExpectType void
+
+wd.setCookie() // $ExpectError
+wd.setCookie({name: str, value: str}) // $ExpectType void
+wd.setCookie([{name: str, value: str}]) // $ExpectType void
+
+wd.clearCookie() // $ExpectType void
+wd.clearCookie(str) // $ExpectType void
+
+wd.seeCookie() // $ExpectError
+wd.seeCookie(str) // $ExpectType void
+
+wd.acceptPopup() // $ExpectType void
+
+wd.cancelPopup() // $ExpectType void
+
+wd.seeInPopup() // $ExpectError
+wd.seeInPopup(str) // $ExpectType void
+
+wd.pressKeyDown() // $ExpectError
+wd.pressKeyDown(str) // $ExpectType void
+
+wd.pressKeyUp() // $ExpectError
+wd.pressKeyUp(str) // $ExpectType void
+
+wd.pressKey() // $ExpectError
+wd.pressKey(str) // $ExpectType void
+
+wd.type() // $ExpectError
+wd.type(str) // $ExpectType void
+
+wd.resizeWindow() // $ExpectError
+wd.resizeWindow(num) // $ExpectError
+wd.resizeWindow(num, num) // $ExpectType void
+
+wd.dragAndDrop() // $ExpectError
+wd.dragAndDrop('div') // $ExpectError
+wd.dragAndDrop('div', 'div') // $ExpectType void
+
+wd.dragSlider() // $ExpectError
+wd.dragSlider('div', num) // $ExpectType void
+
+wd.switchToWindow() // $ExpectError
+wd.switchToWindow(str) // $ExpectType void
+
+wd.closeOtherTabs() // $ExpectType void
+
+wd.wait() // $ExpectError
+wd.wait(num) // $ExpectType void
+
+wd.waitForEnabled() // $ExpectError
+wd.waitForEnabled('div') // $ExpectType void
+wd.waitForEnabled('div', num) // $ExpectType void
+
+wd.waitForElement() // $ExpectError
+wd.waitForElement('div') // $ExpectType void
+wd.waitForElement('div', num) // $ExpectType void
+
+wd.waitForClickable() // $ExpectError
+wd.waitForClickable('div') // $ExpectType void
+wd.waitForClickable('div', num) // $ExpectType void
+
+wd.waitForVisible() // $ExpectError
+wd.waitForVisible('div') // $ExpectType void
+wd.waitForVisible('div', num) // $ExpectType void
+
+wd.waitForInvisible() // $ExpectError
+wd.waitForInvisible('div') // $ExpectType void
+wd.waitForInvisible('div', num) // $ExpectType void
+
+wd.waitToHide() // $ExpectError
+wd.waitToHide('div') // $ExpectType void
+wd.waitToHide('div', num) // $ExpectType void
+
+wd.waitForDetached() // $ExpectError
+wd.waitForDetached('div') // $ExpectType void
+wd.waitForDetached('div', num) // $ExpectType void
+
+wd.waitForFunction() // $ExpectError
+wd.waitForFunction('div') // $ExpectType void
+wd.waitForFunction(() => {}) // $ExpectType void
+wd.waitForFunction(() => {}, [num], num) // $ExpectType void
+wd.waitForFunction(() => {}, [str], num) // $ExpectType void
+
+wd.waitInUrl() // $ExpectError
+wd.waitInUrl(str) // $ExpectType void
+wd.waitInUrl(str, num) // $ExpectType void
+
+wd.waitForText() // $ExpectError
+wd.waitForText(str) // $ExpectType void
+wd.waitForText(str, num, str) // $ExpectType void
+
+wd.waitForValue() // $ExpectError
+wd.waitForValue(str) // $ExpectError
+wd.waitForValue(str, str) // $ExpectType void
+wd.waitForValue(str, str, num) // $ExpectType void
+
+wd.waitNumberOfVisibleElements() // $ExpectError
+wd.waitNumberOfVisibleElements('div') // $ExpectError
+wd.waitNumberOfVisibleElements(str, num) // $ExpectType void
+wd.waitNumberOfVisibleElements(str, num, num) // $ExpectType void
+
+wd.waitUrlEquals() // $ExpectError
+wd.waitUrlEquals(str) // $ExpectType void
+wd.waitUrlEquals(str, num) // $ExpectType void
+
+wd.waitUntil() // $ExpectError
+wd.waitUntil(() => {}) // $ExpectType void
+wd.waitUntil(str) // $ExpectType void
+wd.waitUntil(str, num, str, num) // $ExpectType void
+wd.waitUntil(() => {}, num, str, num) // $ExpectType void
+
+wd.switchTo() // $ExpectType void
+wd.switchTo('div') // $ExpectType void
+
+wd.switchToNextTab(num, num) // $ExpectType void
+
+wd.switchToPreviousTab(num, num) // $ExpectType void
+
+wd.closeCurrentTab() // $ExpectType void
+
+wd.openNewTab() // $ExpectType void
+
+wd.refreshPage() // $ExpectType void
+
+wd.scrollPageToTop() // $ExpectType void
+
+wd.scrollPageToBottom() // $ExpectType void
+
+wd.setGeoLocation() // $ExpectError
+wd.setGeoLocation(num) // $ExpectError
+wd.setGeoLocation(num, num) // $ExpectType void
+wd.setGeoLocation(num, num, num) // $ExpectType void
+
+wd.dontSeeCookie() // $ExpectError
+wd.dontSeeCookie(str) // $ExpectType void
+
+wd.dragAndDrop(); // $ExpectError
+wd.dragAndDrop('#dragHandle'); // $ExpectError
+wd.dragAndDrop('#dragHandle', '#container');
+
+wd.grabTextFromAll() // $ExpectError
+wd.grabTextFromAll('div') // $ExpectType Promise<string[]>
+
+wd.grabTextFrom() // $ExpectError
+wd.grabTextFrom('div') // $ExpectType Promise<string>
+
+wd.grabHTMLFromAll() // $ExpectError
+wd.grabHTMLFromAll('div') // $ExpectType Promise<string[]>
+
+wd.grabHTMLFrom() // $ExpectError
+wd.grabHTMLFrom('div') // $ExpectType Promise<string>
+
+wd.grabValueFromAll() // $ExpectError
+wd.grabValueFromAll('div') // $ExpectType Promise<string[]>
+
+wd.grabValueFrom() // $ExpectError
+wd.grabValueFrom('div') // $ExpectType Promise<string>
+
+wd.grabCssPropertyFromAll() // $ExpectError
+wd.grabCssPropertyFromAll('div') // $ExpectError
+wd.grabCssPropertyFromAll('div', 'color') // $ExpectType Promise<string[]>
+
+wd.grabCssPropertyFrom() // $ExpectError
+wd.grabCssPropertyFrom('div') // $ExpectError
+wd.grabCssPropertyFrom('div', 'color') // $ExpectType Promise<string>
+
+wd.grabAttributeFromAll() // $ExpectError
+wd.grabAttributeFromAll('div') // $ExpectError
+wd.grabAttributeFromAll('div', 'style') // $ExpectType Promise<string[]>
+
+wd.grabAttributeFrom() // $ExpectError
+wd.grabAttributeFrom('div') // $ExpectError
+wd.grabAttributeFrom('div', 'style') // $ExpectType Promise<string>
+
+wd.grabTitle() // $ExpectType Promise<string>
+
+wd.grabSource() // $ExpectType Promise<string>
+
+wd.grabBrowserLogs() // $ExpectType Promise<object[]> | undefined
+
+wd.grabCurrentUrl() // $ExpectType Promise<string>
+
+wd.grabNumberOfVisibleElements() // $ExpectError
+wd.grabNumberOfVisibleElements('div') // $ExpectType Promise<number>
+
+wd.grabCookie(); // $ExpectType Promise<string[]> | Promise<string>
+wd.grabCookie('name'); // $ExpectType Promise<string[]> | Promise<string>
+
+wd.grabPopupText() // $ExpectType Promise<string>
+
+wd.grabAllWindowHandles() // $ExpectType Promise<string[]>
+wd.grabCurrentWindowHandle() // $ExpectType Promise<string>
+
+wd.grabNumberOfOpenTabs() // $ExpectType Promise<number>
+
+const psp = wd.grabPageScrollPosition() // $ExpectType Promise<PageScrollPosition>
+psp.then(
+  result => {
+    result.x // $ExpectType number
+    result.y // $ExpectType number
+  }
+)
+
+wd.grabGeoLocation() // $ExpectType Promise<{ latitude: number; longitude: number; altitude: number; }>
+
+wd.grabElementBoundingRect(); // $ExpectError
+wd.grabElementBoundingRect('h3'); // $ExpectType Promise<number> | Promise<DOMRect>
+wd.grabElementBoundingRect('h3', 'width') // $ExpectType Promise<number> | Promise<DOMRect>
diff --git a/typings/tsconfig.json b/typings/tsconfig.json
new file mode 100644
index 000000000..2ec0512ec
--- /dev/null
+++ b/typings/tsconfig.json
@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "es2018",
+    "lib": ["es2018", "DOM"],
+    "esModuleInterop": true,
+    "module": "commonjs",
+    "strictNullChecks": true,
+    "noImplicitAny": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noImplicitThis": true,
+    "strictFunctionTypes": true,
+    "skipLibCheck": true,
+    "types": [],
+    "noEmit": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": [
+    "**/*.ts"
+  ]
+}
diff --git a/typings/tslint.json b/typings/tslint.json
new file mode 100644
index 000000000..3b4ce5d1f
--- /dev/null
+++ b/typings/tslint.json
@@ -0,0 +1,22 @@
+{
+  "extends": "dtslint/dtslint.json",
+  "rules": {
+    "semicolon": false,
+    "no-empty-interface": false,
+    "interface-name": false,
+    "jsdoc-format": false,
+    "max-line-length": false,
+    "no-single-declare-module": false,
+    "no-unnecessary-qualifier": false,
+    "interface-over-type-literal": false,
+    "no-var-keyword": false,
+    "no-unnecessary-class": false,
+    "array-type": false,
+    "trim-file": false,
+    "no-consecutive-blank-lines": false
+  },
+  "linterOptions": {
+    "exclude": [
+    ]
+  }
+}
diff --git a/typings/utils.d.ts b/typings/utils.d.ts
index 0a1804aca..42e77fb0c 100644
--- a/typings/utils.d.ts
+++ b/typings/utils.d.ts
@@ -1,5 +1,5 @@
-type ValueOf<T> = T[keyof T]
-type KeyValueTupleToObject<T extends [keyof any, any]> = {
+export type ValueOf<T> = T[keyof T]
+export type KeyValueTupleToObject<T extends [keyof any, any]> = {
   [K in T[0]]: Extract<T, [K, any]>[1]
 }
 export type Translate<T, M extends Record<string, string>> = KeyValueTupleToObject<ValueOf<{