Typings for chromium driver

package.json

@@ -233,6 +233,7 @@
     "@types/minimatch": "^2.0.29",
     "@types/node": "^8.10.20",
     "@types/prop-types": "^15.5.3",
+    "@types/puppeteer": "^1.6.2",
     "@types/react": "^16.3.14",
     "@types/react-dom": "^16.0.5",
     "@types/react-redux": "^6.0.6",

x-pack/plugins/reporting/export_types/printable_pdf/server/lib/layouts/layout.ts

@@ -4,7 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 import { Size } from '../../../../../types';
-import { ViewZoomWidthHeight } from './types';
+import { ViewZoomWidthHeight } from '../../../../../types';
 
 export interface PageSizeParams {
   pageMarginTop: number;

x-pack/plugins/reporting/export_types/printable_pdf/server/lib/layouts/preserve_layout.ts

@@ -7,6 +7,7 @@ import path from 'path';
 import { Size } from '../../../../../types';
 import { Layout, PageSizeParams } from './layout';
 
+// We use a zoom of two to bump up the resolution of the screenshot a bit.
 const ZOOM: number = 2;
 
 export class PreserveLayout extends Layout {

x-pack/plugins/reporting/export_types/printable_pdf/server/lib/layouts/print_layout.ts

@@ -4,19 +4,10 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 import path from 'path';
-import { KbnServer, Size } from '../../../../../types';
+import { EvaluateOptions, KbnServer, Size } from '../../../../../types';
 import { Layout } from './layout';
 import { CaptureConfig } from './types';
 
-type EvalArgs = any[];
-
-interface EvaluateOptions {
-  // 'fn' is a function in string form to avoid tslint from auto formatting it into a version not
-  // underfood by transform_fn safeWrap.
-  fn: ((...evalArgs: EvalArgs) => any);
-  args: EvalArgs; // Arguments to be passed into the function defined by fn.
-}
-
 interface BrowserClient {
   evaluate: (evaluateOptions: EvaluateOptions) => void;
 }

x-pack/plugins/reporting/export_types/printable_pdf/server/lib/layouts/types.d.ts

@@ -9,9 +9,3 @@ export interface CaptureConfig {
   zoom: number;
   viewport: Size;
 }
-
-export interface ViewZoomWidthHeight {
-  zoom: number;
-  width: number;
-  height: number;
-}

x-pack/plugins/reporting/server/browsers/chromium/driver/chromium_driver.ts

@@ -0,0 +1,96 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import * as Chrome from 'puppeteer';
+import {
+  ElementPosition,
+  EvalArgs,
+  EvalFn,
+  EvaluateOptions,
+  Logger,
+  ViewZoomWidthHeight,
+} from '../../../../types';
+
+export interface ChromiumDriverOptions {
+  logger: Logger;
+}
+
+const WAIT_FOR_DELAY_MS: number = 100;
+
+export class HeadlessChromiumDriver {
+  public documentNode?: Chrome.JSHandle;
+
+  private readonly page: Chrome.Page;
+  private readonly logger: Logger;
+
+  constructor(page: Chrome.Page, { logger }: ChromiumDriverOptions) {
+    this.page = page;
+    this.logger = logger;
+  }
+
+  public async open(
+    url: string,
+    { headers, waitForSelector }: { headers: Record<string, string>; waitForSelector: string }
+  ) {
+    this.logger.debug(`HeadlessChromiumDriver:opening url ${url}`);
+
+    await this.page.setExtraHTTPHeaders(headers);
+    await this.page.goto(url, { waitUntil: 'networkidle0' });
+
+    this.documentNode = await this.page.evaluateHandle(() => document);
+    await this.page.waitFor(waitForSelector);
+  }
+
+  public async screenshot(elementPosition: ElementPosition) {
+    let clip;
+    if (elementPosition) {
+      const { boundingClientRect, scroll = { x: 0, y: 0 } } = elementPosition;
+      clip = {
+        x: boundingClientRect.left + scroll.x,
+        y: boundingClientRect.top + scroll.y,
+        height: boundingClientRect.height,
+        width: boundingClientRect.width,
+      };
+    }
+
+    const screenshot = await this.page.screenshot({
+      clip,
+    });
+
+    return screenshot.toString('base64');
+  }
+
+  public async evaluate({ fn, args = [] }: EvaluateOptions) {
+    const result = await this.page.evaluate(fn, ...args);
+    return result;
+  }
+
+  public waitForSelector(selector: string) {
+    return this.page.waitFor(selector);
+  }
+
+  public async waitFor<T>({ fn, args, toEqual }: { fn: EvalFn<T>; args: EvalArgs; toEqual: T }) {
+    while (true) {
+      const result = await this.evaluate({ fn, args });
+      if (result === toEqual) {
+        return;
+      }
+
+      await new Promise(r => setTimeout(r, WAIT_FOR_DELAY_MS));
+    }
+  }
+
+  public async setViewport({ width, height, zoom }: ViewZoomWidthHeight) {
+    this.logger.debug(`Setting viewport to width: ${width}, height: ${height}, zoom: ${zoom}`);
+
+    await this.page.setViewport({
+      width: Math.floor(width / zoom),
+      height: Math.floor(height / zoom),
+      deviceScaleFactor: zoom,
+      isMobile: false,
+    });
+  }
+}

x-pack/plugins/reporting/server/browsers/chromium/driver/index.ts

@@ -0,0 +1,7 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+export { HeadlessChromiumDriver } from './chromium_driver';

x-pack/plugins/reporting/types.d.ts

@@ -21,3 +21,35 @@ export interface Logger {
   error: (message: string) => void;
   warning: (message: string) => void;
 }
+
+export interface ViewZoomWidthHeight {
+  zoom: number;
+  width: number;
+  height: number;
+}
+
+export type EvalArgs = any[];
+export type EvalFn<T> = ((...evalArgs: EvalArgs) => T);
+
+export interface EvaluateOptions {
+  fn: EvalFn<any>;
+  args: EvalArgs; // Arguments to be passed into the function defined by fn.
+}
+
+export interface ElementPosition {
+  boundingClientRect: {
+    // modern browsers support x/y, but older ones don't
+    top: number;
+    left: number;
+    width: number;
+    height: number;
+  };
+  scroll: {
+    x: number;
+    y: number;
+  };
+}
+
+export interface HeadlessElementInfo {
+  position: ElementPosition;
+}

yarn.lock

@@ -488,6 +488,13 @@
   version "15.5.3"
   resolved "https://registry.yarnpkg.com/@types/prop-types/-/prop-types-15.5.3.tgz#bef071852dca2a2dbb65fecdb7bfb30cedae2de2"
 
+"@types/puppeteer@^1.6.2":
+  version "1.6.2"
+  resolved "https://registry.yarnpkg.com/@types/puppeteer/-/puppeteer-1.6.2.tgz#9b4ba40a67abad3c729a021ffd259d929d00c5e0"
+  dependencies:
+    "@types/events" "*"
+    "@types/node" "*"
+
 "@types/react-dom@^16.0.5":
   version "16.0.5"
   resolved "https://registry.yarnpkg.com/@types/react-dom/-/react-dom-16.0.5.tgz#a757457662e3819409229e8f86795ff37b371f96"