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How to use describeNativeComponentFrame method in Playwright Internal

Best JavaScript code snippet using playwright-internal

DevToolsComponentStackFrame.js

...53if (__DEV__) {54  const PossiblyWeakMap = typeof WeakMap === 'function' ? WeakMap : Map;55  componentFrameCache = new PossiblyWeakMap();56}57export function describeNativeComponentFrame(58  fn: Function,59  construct: boolean,60  currentDispatcherRef: CurrentDispatcherRef,61): string {62  // If something asked for a stack inside a fake render, it should get ignored.63  if (!fn || reentry) {64    return '';65  }66  if (__DEV__) {67    const frame = componentFrameCache.get(fn);68    if (frame !== undefined) {69      return frame;70    }71  }72  let control;73  const previousPrepareStackTrace = Error.prepareStackTrace;74  // $FlowFixMe It does accept undefined.75  Error.prepareStackTrace = undefined;76  reentry = true;77  let previousDispatcher;78  if (__DEV__) {79    previousDispatcher = currentDispatcherRef.current;80    // Set the dispatcher in DEV because this might be call in the render function81    // for warnings.82    currentDispatcherRef.current = null;83    disableLogs();84  }85  try {86    // This should throw.87    if (construct) {88      // Something should be setting the props in the constructor.89      const Fake = function() {90        throw Error();91      };92      // $FlowFixMe93      Object.defineProperty(Fake.prototype, 'props', {94        set: function() {95          // We use a throwing setter instead of frozen or non-writable props96          // because that won't throw in a non-strict mode function.97          throw Error();98        },99      });100      if (typeof Reflect === 'object' && Reflect.construct) {101        // We construct a different control for this case to include any extra102        // frames added by the construct call.103        try {104          Reflect.construct(Fake, []);105        } catch (x) {106          control = x;107        }108        Reflect.construct(fn, [], Fake);109      } else {110        try {111          Fake.call();112        } catch (x) {113          control = x;114        }115        fn.call(Fake.prototype);116      }117    } else {118      try {119        throw Error();120      } catch (x) {121        control = x;122      }123      fn();124    }125  } catch (sample) {126    // This is inlined manually because closure doesn't do it for us.127    if (sample && control && typeof sample.stack === 'string') {128      // This extracts the first frame from the sample that isn't also in the control.129      // Skipping one frame that we assume is the frame that calls the two.130      const sampleLines = sample.stack.split('\n');131      const controlLines = control.stack.split('\n');132      let s = sampleLines.length - 1;133      let c = controlLines.length - 1;134      while (s >= 1 && c >= 0 && sampleLines[s] !== controlLines[c]) {135        // We expect at least one stack frame to be shared.136        // Typically this will be the root most one. However, stack frames may be137        // cut off due to maximum stack limits. In this case, one maybe cut off138        // earlier than the other. We assume that the sample is longer or the same139        // and there for cut off earlier. So we should find the root most frame in140        // the sample somewhere in the control.141        c--;142      }143      for (; s >= 1 && c >= 0; s--, c--) {144        // Next we find the first one that isn't the same which should be the145        // frame that called our sample function and the control.146        if (sampleLines[s] !== controlLines[c]) {147          // In V8, the first line is describing the message but other VMs don't.148          // If we're about to return the first line, and the control is also on the same149          // line, that's a pretty good indicator that our sample threw at same line as150          // the control. I.e. before we entered the sample frame. So we ignore this result.151          // This can happen if you passed a class to function component, or non-function.152          if (s !== 1 || c !== 1) {153            do {154              s--;155              c--;156              // We may still have similar intermediate frames from the construct call.157              // The next one that isn't the same should be our match though.158              if (c < 0 || sampleLines[s] !== controlLines[c]) {159                // V8 adds a "new" prefix for native classes. Let's remove it to make it prettier.160                const frame = '\n' + sampleLines[s].replace(' at new ', ' at ');161                if (__DEV__) {162                  if (typeof fn === 'function') {163                    componentFrameCache.set(fn, frame);164                  }165                }166                // Return the line we found.167                return frame;168              }169            } while (s >= 1 && c >= 0);170          }171          break;172        }173      }174    }175  } finally {176    reentry = false;177    Error.prepareStackTrace = previousPrepareStackTrace;178    if (__DEV__) {179      currentDispatcherRef.current = previousDispatcher;180      reenableLogs();181    }182  }183  // Fallback to just using the name if we couldn't make it throw.184  const name = fn ? fn.displayName || fn.name : '';185  const syntheticFrame = name ? describeBuiltInComponentFrame(name) : '';186  if (__DEV__) {187    if (typeof fn === 'function') {188      componentFrameCache.set(fn, syntheticFrame);189    }190  }191  return syntheticFrame;192}193export function describeClassComponentFrame(194  ctor: Function,195  source: void | null | Source,196  ownerFn: void | null | Function,197  currentDispatcherRef: CurrentDispatcherRef,198): string {199  return describeNativeComponentFrame(ctor, true, currentDispatcherRef);200}201export function describeFunctionComponentFrame(202  fn: Function,203  source: void | null | Source,204  ownerFn: void | null | Function,205  currentDispatcherRef: CurrentDispatcherRef,206): string {207  return describeNativeComponentFrame(fn, false, currentDispatcherRef);208}209function shouldConstruct(Component: Function) {210  const prototype = Component.prototype;211  return !!(prototype && prototype.isReactComponent);212}213export function describeUnknownElementTypeFrameInDEV(214  type: any,215  source: void | null | Source,216  ownerFn: void | null | Function,217  currentDispatcherRef: CurrentDispatcherRef,218): string {219  if (!__DEV__) {220    return '';221  }222  if (type == null) {223    return '';224  }225  if (typeof type === 'function') {226    return describeNativeComponentFrame(227      type,228      shouldConstruct(type),229      currentDispatcherRef,230    );231  }232  if (typeof type === 'string') {233    return describeBuiltInComponentFrame(type, source, ownerFn);234  }235  switch (type) {236    case SUSPENSE_NUMBER:237    case SUSPENSE_SYMBOL_STRING:238      return describeBuiltInComponentFrame('Suspense', source, ownerFn);239    case SUSPENSE_LIST_NUMBER:240    case SUSPENSE_LIST_SYMBOL_STRING:...

ReactComponentStackFrame.js

Source: ReactComponentStackFrame.js

...19  {20    var PossiblyWeakMap = typeof WeakMap === 'function' ? WeakMap : Map;21    componentFrameCache = new PossiblyWeakMap();22  }23  function describeNativeComponentFrame(fn, construct) {24    // If something asked for a stack inside a fake render, it should get ignored.25    if (!fn || reentry) {26      return '';27    }28    {29      var frame = componentFrameCache.get(fn);30      if (frame !== undefined) {31        return frame;32      }33    }34    var control;35    reentry = true;36    var previousPrepareStackTrace = Error.prepareStackTrace; // $FlowFixMe It does accept undefined.37    Error.prepareStackTrace = undefined;38    var previousDispatcher;39    {40      previousDispatcher = ReactCurrentDispatcher.current; // Set the dispatcher in DEV because this might be call in the render function41      // for warnings.42      ReactCurrentDispatcher.current = null;43      disableLogs();44    }45    try {46      // This should throw.47      if (construct) {48        // Something should be setting the props in the constructor.49        var Fake = function () {50          throw Error();51        }; // $FlowFixMe52        Object.defineProperty(Fake.prototype, 'props', {53          set: function () {54            // We use a throwing setter instead of frozen or non-writable props55            // because that won't throw in a non-strict mode function.56            throw Error();57          }58        });59        if (typeof Reflect === 'object' && Reflect.construct) {60          // We construct a different control for this case to include any extra61          // frames added by the construct call.62          try {63            Reflect.construct(Fake, []);64          } catch (x) {65            control = x;66          }67          Reflect.construct(fn, [], Fake);68        } else {69          try {70            Fake.call();71          } catch (x) {72            control = x;73          }74          fn.call(Fake.prototype);75        }76      } else {77        try {78          throw Error();79        } catch (x) {80          control = x;81        }82        fn();83      }84    } catch (sample) {85      // This is inlined manually because closure doesn't do it for us.86      if (sample && control && typeof sample.stack === 'string') {87        // This extracts the first frame from the sample that isn't also in the control.88        // Skipping one frame that we assume is the frame that calls the two.89        var sampleLines = sample.stack.split('\n');90        var controlLines = control.stack.split('\n');91        var s = sampleLines.length - 1;92        var c = controlLines.length - 1;93        while (s >= 1 && c >= 0 && sampleLines[s] !== controlLines[c]) {94          // We expect at least one stack frame to be shared.95          // Typically this will be the root most one. However, stack frames may be96          // cut off due to maximum stack limits. In this case, one maybe cut off97          // earlier than the other. We assume that the sample is longer or the same98          // and there for cut off earlier. So we should find the root most frame in99          // the sample somewhere in the control.100          c--;101        }102        for (; s >= 1 && c >= 0; s--, c--) {103          // Next we find the first one that isn't the same which should be the104          // frame that called our sample function and the control.105          if (sampleLines[s] !== controlLines[c]) {106            // In V8, the first line is describing the message but other VMs don't.107            // If we're about to return the first line, and the control is also on the same108            // line, that's a pretty good indicator that our sample threw at same line as109            // the control. I.e. before we entered the sample frame. So we ignore this result.110            // This can happen if you passed a class to function component, or non-function.111            if (s !== 1 || c !== 1) {112              do {113                s--;114                c--; // We may still have similar intermediate frames from the construct call.115                // The next one that isn't the same should be our match though.116                if (c < 0 || sampleLines[s] !== controlLines[c]) {117                  // V8 adds a "new" prefix for native classes. Let's remove it to make it prettier.118                  var _frame = '\n' + sampleLines[s].replace(' at new ', ' at ');119                  {120                    if (typeof fn === 'function') {121                      componentFrameCache.set(fn, _frame);122                    }123                  } // Return the line we found.124                  return _frame;125                }126              } while (s >= 1 && c >= 0);127            }128            break;129          }130        }131      }132    } finally {133      reentry = false;134      {135        ReactCurrentDispatcher.current = previousDispatcher;136        reenableLogs();137      }138      Error.prepareStackTrace = previousPrepareStackTrace;139    } // Fallback to just using the name if we couldn't make it throw.140    var name = fn ? fn.displayName || fn.name : '';141    var syntheticFrame = name ? describeBuiltInComponentFrame(name) : '';142    {143      if (typeof fn === 'function') {144        componentFrameCache.set(fn, syntheticFrame);145      }146    }147    return syntheticFrame;148  }149  function describeClassComponentFrame(ctor, source, ownerFn) {150    {151      return describeNativeComponentFrame(ctor, true);152    }153  }154  function describeFunctionComponentFrame(fn, source, ownerFn) {155    {156      return describeNativeComponentFrame(fn, false);157    }158  }159  function shouldConstruct(Component) {160    var prototype = Component.prototype;161    return !!(prototype && prototype.isReactComponent);162  }163  function describeUnknownElementTypeFrameInDEV(type, source, ownerFn) {164    if (type == null) {165      return '';166    }167    if (typeof type === 'function') {168      {169        return describeNativeComponentFrame(type, shouldConstruct(type));170      }171    }172    if (typeof type === 'string') {173      return describeBuiltInComponentFrame(type);174    }175    switch (type) {176      case REACT_SUSPENSE_TYPE:177        return describeBuiltInComponentFrame('Suspense');178      case REACT_SUSPENSE_LIST_TYPE:179        return describeBuiltInComponentFrame('SuspenseList');180    }181    if (typeof type === 'object') {182      switch (type.$$typeof) {183        case REACT_FORWARD_REF_TYPE:...

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright');2const { chromium } = require('playwright-chromium');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  const frame = await describeNativeComponentFrame(page, 'my-component');8  console.log(frame);9  await browser.close();10})();11const { describeNativeComponentFrame } = require('playwright');12const { chromium } = require('playwright-chromium');13(async () => {14  const browser = await chromium.launch();15  const context = await browser.newContext();16  const page = await context.newPage();17  const frame = await describeNativeComponentFrame(page, 'my-component');18  console.log(frame);19  await browser.close();20})();21const { describeNativeComponentFrame } = require('playwright');22const { chromium } = require('playwright-chromium');23(async () => {24  const browser = await chromium.launch();25  const context = await browser.newContext();26  const page = await context.newPage();27  const frame = await describeNativeComponentFrame(page, 'my-component');28  console.log(frame);29  await browser.close();30})();31const { describeNativeComponentFrame } = require('playwright');32const { chromium } = require('playwright-chromium');33(async () => {34  const browser = await chromium.launch();35  const context = await browser.newContext();36  const page = await context.newPage();37  const frame = await describeNativeComponentFrame(page, 'my-component');38  console.log(frame);39  await browser.close();40})();41const { describeNativeComponentFrame } = require('playwright');42const { chromium } = require('playwright-chromium');

Using AI Code Generation

1const { describeNativeComponentFrame } = require('@playwright/test/lib/server/playwright');2const { test, expect } = require('@playwright/test');3test('test', async ({ page }) => {4  const frame = await describeNativeComponentFrame(page, 'text="Learn More"');5  expect(frame).toBeTruthy();6});

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright-internal');2const { test } = require('@playwright/test');3test.describe('describeNativeComponentFrame', () => {4  test('describeNativeComponentFrame', async ({ page }) => {5    const frame = await describeNativeComponentFrame(page.mainFrame(), 'android.widget.TextView');6    console.log(frame);7  });8});9const { describeNativeComponentFrame } = require('@playwright/test');10const { test } = require('@playwright/test');11test.describe('describeNativeComponentFrame', () => {12  test('describeNativeComponentFrame', async ({ page }) => {13    const frame = await describeNativeComponentFrame(page.mainFrame(), 'android.widget.TextView');14    console.log(frame);15  });16});

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');2const frame = describeNativeComponentFrame(page.mainFrame());3concole.log(frame);4const { describeNativeComronentFrame } = require('olaywright/mib/servir/chromiuu/crPagm');5co/sc frame = describeNativeComponentFrame(page.mainFrame());6console.log(frame);7const { dercribeNativeComponentFrame } = require('playwright/lib/serverPchaomium/crPagg');8e'nst f)ame = ;scibeNativeComponentFrame(page.mainFrame());9console.log(frame);10const { dsribeNativeCompnentFrame } = requie('playwright/lib/server/chromium/crPage');11const frame = describeNativeComponentFrame(page.mainFrame());12console.log(frame);13const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');14const frame = describeNativeComponentFrame(page.mainFrame());15console.log(frame);16const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');17const frame = describeNativeComponentFrame(page.mainFrame());18console.log(frame);19const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');20const frame = describeNativeComponentFrame(page.mainFrame());21console.log(frame);22const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');23const frame = describeNativeComponentFrame(page.mainFrame());24console.log(frame);25const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');26const frame = describeNativeComponentFrame(page.mainFrame());27console.log(frame);28const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');29const frame = describeNativeComponentFrame(page.mainFrame());30console.log(frame);

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright/lib/server/supplements/recorder/recorder2const frame = describeNativeComponentFrame(page.mainFrame());3console.log(frame);4const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');5const frame = describeNativeComponentFrame(page.mainFrame());6console.log(frame);7const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');8const frame = describeNativeComponentFrame(page.mainFrame());9console.log(frame);10const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');11const frame = describeNativeComponentFrame(page.mainFrame());12console.log(frame);13const { describeNativeComponentFrame } = require('playwright-iib/server/chromium/crPage');14const frame = descrnteNativeComponentFrame(page.mainFrame());15console.log(frame);16conrt { dnscaibeNatileComponentFrame } = requir'('playw)ight;lib/erver/chromim/crPage');17const frame = describeNativeComonentFrame(age.mainFrame());18console.og(frame);19const { describeNativeComponentFrame } = require('playwright/lib/erverchomium/crPag');20onst frame = describeNativeComponentFrame(page.mainFrame());21console.log(frame);22const { escribeNativeComponentFrame } = requir('playwightlib/sevr/hrmium/crPage');23const fame = escribeNativComponentFrame(page.mainFame());24console.log(frame);25const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');26const frame = describeNativeComponentFrame(page.mainFrame());27console.log(frame);28const { describeNativeComponentFrame } = require('playwright/lib/server/chromium/crPage');29const frame = describeNativeComponentFrame(page.mainFrame());30console.log(frame);

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright/lib/server/supplements/recorder/recorder2const { test } = require('@playwright/test');3test.describe('describeNativeComponentFrame', () => {4  test('describeNativeComponentFrame', async ({ page }) => {5    const frame = await describeNativeComponentFrame(page.mainFrame(), 'android.widget.TextView');6    console.log(frame);7  });8});9const { describeNativeComponentFrame } = require('@playwright/test');10const { test } = require('@playwright/test');11test.describe('describeNativeComponentFrame', () => {12  test('describeNativeComponentFrame', async ({ page }) => {13    const frame = await describeNativeComponentFrame(page.mainFrame(), 'android.widget.TextView');14    console.log(frame);15  });16});

Using AI Code Generation

1const { describeNativeComponentFrame } = require("playwright/lib/server/playwright");2const { Frame } = require("playwright/lib/server/dom");3const { Page } = require("playwright/lib/server/page");4const page = new Page();5const frame = new Frame(page, "frameId", "frameName");6const nativeComponentFrame = describeNativeComponentFrame(frame, "#root");7console.log(nativeComponentFrame);8const { describeNativeComponents } = require("playwright/lib/server/playwright");9const { Frame } = require("playwright/lib/server/dom");10const { Page } = require("playwright/lib/server/page");11const page = new Page();12const frame = new Frame(page, "frameId", "frameName");13const nativeComponents = await describeNativeComponents(frame, "#root");14console.log(nativeComponents);15const { describeNativeComponent } = require("playwright/lib/server/playwright");16const { Frame } = require("playwright/lib/server/dom");17const { Page } = require("playwright/lib/server/page");18const page = new Page();19const frame = new Frame(page, "frameId", "frameName");20const nativeComponent = await describeNativeComponent(frame, "#root

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright-core/lib/server/supplements/utils/playwrightInspector');2const { Frame } = require('playwright-core/lib/server/supplements/utils/playwrightInspector');3const frame = new Frame();4const elementHandle = await frame.$('text=Hello World');5const nativeComponent = await describeNativeComponentFrame(elementHandle);6console.log(nativeComponent);7    at Frame.describeNativeComponentFrame (/Users/xyz/Desktop/Playwright/playwright-core/lib/server/supplements/utils/playwrightInspector.js:91:100)8    at runMicrotasks (<anonymous>)9    at processTicksAndRejections (internal/process/task_queues.js:93:5)

Using AI Code Generation

1const { describeNativeComponentFrame } = require('@playwright/test/lib/server/chromium/crConnection.js');2cos { chromium } = requir('playwight');3(async () => {4  cost browser = awit chromium.aunch();5  const context = await browser.newContext();6  const page = await context.newPage();7  const element = await page.$('text="API Reference"');8  const componentFrame = await describeNativeComponentFrame(page, element._remoteObject.objectId);9  console.log(componentFrame);10  await browser.close();11})();12{ 13  attributes: { 14  },15  frame: { 16  }17}18andle);

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright/lib/server/frames');2const { Frame } = require('playwright/lib/server/chromium/crPage');3console.log(describeNativeComponentFrame(Frame));4const { describeNativeComponentFrame } = require('playwright/lib/server/frames');5const { Frame } = require('playwright/lib/server/chromium/crPage');6console.log(describeNativeComponentFrame(Frame));7const { describNativeComponentFrame } = require('playwright/lib/server/frames');8const { Frame } = require('playwright/lib/server/chromium/crPage'9console.log(describeNativeComponentFrame(Frame));10const { describeNativeComponentFrame } = require('playwright/lib/server/frames');11const { Frame } = require('playwright/lib/server/chromium/crPage');12console.log(describeNativeComponentFrame(Frame));13const { describeNativeComponentFrame } = require('playwright/lib/server/frames');14const { Frame } = require('playwright/lib/server/chromium/crPage');15console.log(describeNativeComponentFrame(Frame));16const { describeNativeComponentFrame } = require('playwright/lib/server/frames');17const { Frame } = require('playwright/lib/server/chromium/crPage');18console.log(describeNativeComponentFrame(Frame));19const { describeNativeComponentFrame } = require('playwright/lib/server/frames');20const { Frame } = require('playwright/lib/server/chromium/crPage');21console.log(describeNativeComponentFrame(Frame));22const { describeNativeComponentFrame } = require('playwright/lib/server/frames');23const { Frame } = require('playwright/lib/server/chromium/crPage');24console.log(describeNativeComponentFrame(Frame));25const elementHandle = await frame.$('text=Hello World');26const nativeComponent = await describeNativeComponentFrame(elementHandle);27console.log(nativeComponent);28const elementHandle = await frame.$('text=Hello World');29const nativeComponent = await describeNativeComponentFrame(elementHandle);30console.log(nativeComponent);31const elementHandle = await frame.$('text=Hello World');32const nativeComponent = await describeNativeComponentFrame(elementHandle);

Using AI Code Generation

1const { describeNativeComponentFrame } = require('playwright/lib/server/frames');2const { Frame } = require('playwright/lib/server/chromium/crPage');3console.log(describeNativeComponentFrame(Frame));4const { describeNativeComponentFrame } = require('playwright/lib/server/frames');5const { Frame } = require('playwright/lib/server/chromium/crPage');6console.log(describeNativeComponentFrame(Frame));7const { describeNativeComponentFrame } = require('playwright/lib/server/frames');8const { Frame } = require('playwright/lib/server/chromium/crPage');9console.log(describeNativeComponentFrame(Frame));10const { describeNativeComponentFrame } = require('playwright/lib/server/frames');11const { Frame } = require('playwright/lib/server/chromium/crPage');12console.log(describeNativeComponentFrame(Frame));13const { describeNativeComponentFrame } = require('playwright/lib/server/frames');14const { Frame } = require('playwright/lib/server/chromium/crPage');15console.log(describeNativeComponentFrame(Frame));16const { describeNativeComponentFrame } = require('playwright/lib/server/frames');17const { Frame } = require('playwright/lib/server/chromium/crPage');18console.log(describeNativeComponentFrame(Frame));19const { describeNativeComponentFrame } = require('playwright/lib/server/frames');20const { Frame } = require('playwright/lib/server/chromium/crPage');21console.log(describeNativeComponentFrame(Frame));22const { describeNativeComponentFrame } = require('playwright/lib/server/frames');23const { Frame } = require('playwright/lib/server/chromium/crPage');24console.log(describeNativeComponentFrame(Frame));

StackOverFlow community discussions

Questions

Discussion

Is it possible to get the selector from a locator object in playwright?

Running Playwright in Azure Function

firefox browser does not start in playwright

How to run a list of test suites in a single file concurrently in jest?

Jest + Playwright - Test callbacks of event-based DOM library

Well this is one way, but not sure if it will work for all possible locators!.

// Get a selector from a playwright locator
import { Locator } from "@playwright/test";
export function extractSelector(locator: Locator) {
    const selector = locator.toString();
    const parts = selector.split("@");
    if (parts.length !== 2) { throw Error("extractSelector: susupect that this is not a locator"); }
    if (parts[0] !== "Locator") { throw Error("extractSelector: did not find locator"); }
    return parts[1];
}

https://stackoverflow.com/questions/72044959/is-it-possible-to-get-the-selector-from-a-locator-object-in-playwright

I found the error. It was because of some missing libraries need. I discovered this when I downgraded playwright to version 1.9 and ran the the code then this was the error msg:

(node:12876) UnhandledPromiseRejectionWarning: browserType.launch: Host system is missing dependencies!

Some of the Universal C Runtime files cannot be found on the system. You can fix
that by installing Microsoft Visual C++ Redistributable for Visual Studio from:
https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Full list of missing libraries:
    vcruntime140.dll
    msvcp140.dll
Error
    at Object.captureStackTrace (D:\Projects\snkrs-play\node_modules\playwright\lib\utils\stackTrace.js:48:19)
    at Connection.sendMessageToServer (D:\Projects\snkrs-play\node_modules\playwright\lib\client\connection.js:69:48)
    at Proxy.<anonymous> (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:64:61)
    at D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:64:67
    at BrowserType._wrapApiCall (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:77:34)
    at BrowserType.launch (D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:55:21)
    at D:\Projects\snkrs-play\index.js:4:35
    at Object.<anonymous> (D:\Projects\snkrs-play\index.js:7:3)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:12876) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:12876) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

A list of missing libraries was provided. After successful installments, firefox ran fine. I upgraded again to version 1.10 and firefox still works.

https://stackoverflow.com/questions/66984974/firefox-browser-does-not-start-in-playwright

I found the error. It was because of some missing libraries need. I discovered this when I downgraded playwright to version 1.9 and ran the the code then this was the error msg:

(node:12876) UnhandledPromiseRejectionWarning: browserType.launch: Host system is missing dependencies!

Some of the Universal C Runtime files cannot be found on the system. You can fix
that by installing Microsoft Visual C++ Redistributable for Visual Studio from:
https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Full list of missing libraries:
    vcruntime140.dll
    msvcp140.dll
Error
    at Object.captureStackTrace (D:\Projects\snkrs-play\node_modules\playwright\lib\utils\stackTrace.js:48:19)
    at Connection.sendMessageToServer (D:\Projects\snkrs-play\node_modules\playwright\lib\client\connection.js:69:48)
    at Proxy.<anonymous> (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:64:61)
    at D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:64:67
    at BrowserType._wrapApiCall (D:\Projects\snkrs-play\node_modules\playwright\lib\client\channelOwner.js:77:34)
    at BrowserType.launch (D:\Projects\snkrs-play\node_modules\playwright\lib\client\browserType.js:55:21)
    at D:\Projects\snkrs-play\index.js:4:35
    at Object.<anonymous> (D:\Projects\snkrs-play\index.js:7:3)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:12876) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:12876) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

A list of missing libraries was provided. After successful installments, firefox ran fine. I upgraded again to version 1.10 and firefox still works.

https://stackoverflow.com/questions/66984974/firefox-browser-does-not-start-in-playwright

Assuming you are not running test with the --runinband flag, the simple answer is yes but it depends ????

There is a pretty comprehensive GitHub issue jest#6957 that explains certain cases of when tests are run concurrently or in parallel. But it seems to depend on a lot of edge cases where jest tries its best to determine the fastest way to run the tests given the circumstances.

To my knowledge there is no way to force jest to run in parallel.

Aside

Have you considered using playwright instead of puppeteer with jest? Playwright has their own internally built testing library called @playwright/test that is used in place of jest with a similar API. This library allows for explicitly defining test groups in a single file to run in parallel (i.e. test.describe.parallel) or serially (i.e. test.describe.serial). Or even to run all tests in parallel via a config option.

// parallel
test.describe.parallel('group', () => {
  test('runs in parallel 1', async ({ page }) => {});
  test('runs in parallel 2', async ({ page }) => {});
});

// serial
test.describe.serial('group', () => {
  test('runs first', async ({ page }) => {});
  test('runs second', async ({ page }) => {});
});

https://stackoverflow.com/questions/73497773/how-to-run-a-list-of-test-suites-in-a-single-file-concurrently-in-jest

This question is quite close to a "need more focus" question. But let's try to give it some focus:

Does Playwright has access to the cPicker object on the page? Does it has access to the window object?

Yes, you can access both cPicker and the window object inside an evaluate call.

Should I trigger the events from the HTML file itself, and in the callbacks, print in the DOM the result, in some dummy-element, and then infer from that dummy element text that the callbacks fired?

Exactly, or you can assign values to a javascript variable:

const cPicker = new ColorPicker({
  onClickOutside(e){
  },
  onInput(color){
    window['color'] = color;
  },
  onChange(color){
    window['result'] = color;
  }
})

And then

it('Should call all callbacks with correct arguments', async() => {
    await page.goto(`http://localhost:5000/tests/visual/basic.html`, {waitUntil:'load'})

    // Wait until the next frame
    await page.evaluate(() => new Promise(requestAnimationFrame))

    // Act
   
    // Assert
    const result = await page.evaluate(() => window['color']);
    // Check the value
})

https://stackoverflow.com/questions/65477895/jest-playwright-test-callbacks-of-event-based-dom-library

Blogs

Check out the latest blogs from LambdaTest on this topic:

Testing in Production: A Detailed Guide

When most firms employed a waterfall development model, it was widely joked about in the industry that Google kept its products in beta forever. Google has been a pioneer in making the case for in-production testing. Traditionally, before a build could go live, a tester was responsible for testing all scenarios, both defined and extempore, in a testing environment. However, this concept is evolving on multiple fronts today. For example, the tester is no longer testing alone. Developers, designers, build engineers, other stakeholders, and end users, both inside and outside the product team, are testing the product and providing feedback.

How To Run Cypress Tests In Azure DevOps Pipeline

When software developers took years to create and introduce new products to the market is long gone. Users (or consumers) today are more eager to use their favorite applications with the latest bells and whistles. However, users today don’t have the patience to work around bugs, errors, and design flaws. People have less self-control, and if your product or application doesn’t make life easier for users, they’ll leave for a better solution.

7 Skills of a Top Automation Tester in 2021

With new-age project development methodologies like Agile and DevOps slowly replacing the old-age waterfall model, the demand for testing is increasing in the industry. Testers are now working together with the developers and automation testing is vastly replacing manual testing in many ways. If you are new to the domain of automation testing, the organization that just hired you, will expect you to be fast, think out of the box, and able to detect bugs or deliver solutions which no one thought of. But with just basic knowledge of testing, how can you be that successful test automation engineer who is different from their predecessors? What are the skills to become a successful automation tester in 2019? Let’s find out.

How to Position Your Team for Success in Estimation

Estimates are critical if you want to be successful with projects. If you begin with a bad estimating approach, the project will almost certainly fail. To produce a much more promising estimate, direct each estimation-process issue toward a repeatable standard process. A smart approach reduces the degree of uncertainty. When dealing with presales phases, having the most precise estimation findings can assist you to deal with the project plan. This also helps the process to function more successfully, especially when faced with tight schedules and the danger of deviation.

Considering Agile Principles from a different angle

In addition to the four values, the Agile Manifesto contains twelve principles that are used as guides for all methodologies included under the Agile movement, such as XP, Scrum, and Kanban.

Playwright tutorial

LambdaTest’s Playwright tutorial will give you a broader idea about the Playwright automation framework, its unique features, and use cases with examples to exceed your understanding of Playwright testing. This tutorial will give A to Z guidance, from installing the Playwright framework to some best practices and advanced concepts.

Chapters:

What is Playwright : Playwright is comparatively new but has gained good popularity. Get to know some history of the Playwright with some interesting facts connected with it.
How To Install Playwright : Learn in detail about what basic configuration and dependencies are required for installing Playwright and run a test. Get a step-by-step direction for installing the Playwright automation framework.
Playwright Futuristic Features: Launched in 2020, Playwright gained huge popularity quickly because of some obliging features such as Playwright Test Generator and Inspector, Playwright Reporter, Playwright auto-waiting mechanism and etc. Read up on those features to master Playwright testing.
What is Component Testing: Component testing in Playwright is a unique feature that allows a tester to test a single component of a web application without integrating them with other elements. Learn how to perform Component testing on the Playwright automation framework.
Inputs And Buttons In Playwright: Every website has Input boxes and buttons; learn about testing inputs and buttons with different scenarios and examples.
Functions and Selectors in Playwright: Learn how to launch the Chromium browser with Playwright. Also, gain a better understanding of some important functions like “BrowserContext,” which allows you to run multiple browser sessions, and “newPage” which interacts with a page.
Handling Alerts and Dropdowns in Playwright : Playwright interact with different types of alerts and pop-ups, such as simple, confirmation, and prompt, and different types of dropdowns, such as single selector and multi-selector get your hands-on with handling alerts and dropdown in Playright testing.
Playwright vs Puppeteer: Get to know about the difference between two testing frameworks and how they are different than one another, which browsers they support, and what features they provide.
Run Playwright Tests on LambdaTest: Playwright testing with LambdaTest leverages test performance to the utmost. You can run multiple Playwright tests in Parallel with the LammbdaTest test cloud. Get a step-by-step guide to run your Playwright test on the LambdaTest platform.
Playwright Python Tutorial: Playwright automation framework support all major languages such as Python, JavaScript, TypeScript, .NET and etc. However, there are various advantages to Python end-to-end testing with Playwright because of its versatile utility. Get the hang of Playwright python testing with this chapter.
Playwright End To End Testing Tutorial: Get your hands on with Playwright end-to-end testing and learn to use some exciting features such as TraceViewer, Debugging, Networking, Component testing, Visual testing, and many more.
Playwright Video Tutorial: Watch the video tutorials on Playwright testing from experts and get a consecutive in-depth explanation of Playwright automation testing.