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| 1 | +// @source @testing-library/dom/src/wait-for.js |
| 2 | +import {getConfig} from '@testing-library/dom' |
| 3 | +import { |
| 4 | + getWindowFromNode, |
| 5 | + getDocument, |
| 6 | + jestFakeTimersAreEnabled, |
| 7 | + // We import these from the helpers rather than using the global version |
| 8 | + // because these will be *real* timers, regardless of whether we're in |
| 9 | + // an environment that's faked the timers out. |
| 10 | + checkContainerType, |
| 11 | +} from './dtlHelpers' |
| 12 | + |
| 13 | +// Not supported for external libraries. Only supported internally in @testing-library/dom |
| 14 | +function runWithExpensiveErrorDiagnosticsDisabled(callback) { |
| 15 | + return callback() |
| 16 | +} |
| 17 | + |
| 18 | +// This is so the stack trace the developer sees is one that's |
| 19 | +// closer to their code (because async stack traces are hard to follow). |
| 20 | +function copyStackTrace(target, source) { |
| 21 | + target.stack = source.stack.replace(source.message, target.message) |
| 22 | +} |
| 23 | + |
| 24 | +function waitFor( |
| 25 | + callback, |
| 26 | + { |
| 27 | + container = getDocument(), |
| 28 | + timeout = getConfig().asyncUtilTimeout, |
| 29 | + showOriginalStackTrace = getConfig().showOriginalStackTrace, |
| 30 | + stackTraceError, |
| 31 | + interval = 50, |
| 32 | + onTimeout = error => { |
| 33 | + error.message = getConfig().getElementError( |
| 34 | + error.message, |
| 35 | + container, |
| 36 | + ).message |
| 37 | + return error |
| 38 | + }, |
| 39 | + mutationObserverOptions = { |
| 40 | + subtree: true, |
| 41 | + childList: true, |
| 42 | + attributes: true, |
| 43 | + characterData: true, |
| 44 | + }, |
| 45 | + }, |
| 46 | +) { |
| 47 | + if (typeof callback !== 'function') { |
| 48 | + throw new TypeError('Received `callback` arg must be a function') |
| 49 | + } |
| 50 | + |
| 51 | + return new Promise(async (resolve, reject) => { |
| 52 | + let lastError, intervalId, observer |
| 53 | + let finished = false |
| 54 | + let promiseStatus = 'idle' |
| 55 | + |
| 56 | + const overallTimeoutTimer = setTimeout(handleTimeout, timeout) |
| 57 | + |
| 58 | + const usingJestFakeTimers = jestFakeTimersAreEnabled() |
| 59 | + if (usingJestFakeTimers) { |
| 60 | + checkCallback() |
| 61 | + // this is a dangerous rule to disable because it could lead to an |
| 62 | + // infinite loop. However, eslint isn't smart enough to know that we're |
| 63 | + // setting finished inside `onDone` which will be called when we're done |
| 64 | + // waiting or when we've timed out. |
| 65 | + // eslint-disable-next-line no-unmodified-loop-condition |
| 66 | + while (!finished) { |
| 67 | + if (!jestFakeTimersAreEnabled()) { |
| 68 | + const error = new Error( |
| 69 | + `Changed from using fake timers to real timers while using waitFor. This is not allowed and will result in very strange behavior. Please ensure you're awaiting all async things your test is doing before changing to real timers. For more info, please go to https://github.com/testing-library/dom-testing-library/issues/830`, |
| 70 | + ) |
| 71 | + if (!showOriginalStackTrace) copyStackTrace(error, stackTraceError) |
| 72 | + reject(error) |
| 73 | + return |
| 74 | + } |
| 75 | + // we *could* (maybe should?) use `advanceTimersToNextTimer` but it's |
| 76 | + // possible that could make this loop go on forever if someone is using |
| 77 | + // third party code that's setting up recursive timers so rapidly that |
| 78 | + // the user's timer's don't get a chance to resolve. So we'll advance |
| 79 | + // by an interval instead. (We have a test for this case). |
| 80 | + jest.advanceTimersByTime(interval) |
| 81 | + |
| 82 | + // It's really important that checkCallback is run *before* we flush |
| 83 | + // in-flight promises. To be honest, I'm not sure why, and I can't quite |
| 84 | + // think of a way to reproduce the problem in a test, but I spent |
| 85 | + // an entire day banging my head against a wall on this. |
| 86 | + checkCallback() |
| 87 | + |
| 88 | + // In this rare case, we *need* to wait for in-flight promises |
| 89 | + // to resolve before continuing. We don't need to take advantage |
| 90 | + // of parallelization so we're fine. |
| 91 | + // https://stackoverflow.com/a/59243586/971592 |
| 92 | + // eslint-disable-next-line no-await-in-loop |
| 93 | + await new Promise(r => { |
| 94 | + setTimeout(r, 0) |
| 95 | + jest.advanceTimersByTime(0) |
| 96 | + }) |
| 97 | + } |
| 98 | + } else { |
| 99 | + try { |
| 100 | + checkContainerType(container) |
| 101 | + } catch (e) { |
| 102 | + reject(e) |
| 103 | + return |
| 104 | + } |
| 105 | + intervalId = setInterval(checkRealTimersCallback, interval) |
| 106 | + const {MutationObserver} = getWindowFromNode(container) |
| 107 | + observer = new MutationObserver(checkRealTimersCallback) |
| 108 | + observer.observe(container, mutationObserverOptions) |
| 109 | + checkCallback() |
| 110 | + } |
| 111 | + |
| 112 | + function onDone(error, result) { |
| 113 | + finished = true |
| 114 | + clearTimeout(overallTimeoutTimer) |
| 115 | + |
| 116 | + if (!usingJestFakeTimers) { |
| 117 | + clearInterval(intervalId) |
| 118 | + observer.disconnect() |
| 119 | + } |
| 120 | + |
| 121 | + if (error) { |
| 122 | + reject(error) |
| 123 | + } else { |
| 124 | + resolve(result) |
| 125 | + } |
| 126 | + } |
| 127 | + |
| 128 | + function checkRealTimersCallback() { |
| 129 | + if (jestFakeTimersAreEnabled()) { |
| 130 | + const error = new Error( |
| 131 | + `Changed from using real timers to fake timers while using waitFor. This is not allowed and will result in very strange behavior. Please ensure you're awaiting all async things your test is doing before changing to fake timers. For more info, please go to https://github.com/testing-library/dom-testing-library/issues/830`, |
| 132 | + ) |
| 133 | + if (!showOriginalStackTrace) copyStackTrace(error, stackTraceError) |
| 134 | + return reject(error) |
| 135 | + } else { |
| 136 | + return checkCallback() |
| 137 | + } |
| 138 | + } |
| 139 | + |
| 140 | + function checkCallback() { |
| 141 | + if (promiseStatus === 'pending') return |
| 142 | + try { |
| 143 | + const result = runWithExpensiveErrorDiagnosticsDisabled(callback) |
| 144 | + if (typeof result?.then === 'function') { |
| 145 | + promiseStatus = 'pending' |
| 146 | + result.then( |
| 147 | + resolvedValue => { |
| 148 | + promiseStatus = 'resolved' |
| 149 | + onDone(null, resolvedValue) |
| 150 | + }, |
| 151 | + rejectedValue => { |
| 152 | + promiseStatus = 'rejected' |
| 153 | + lastError = rejectedValue |
| 154 | + }, |
| 155 | + ) |
| 156 | + } else { |
| 157 | + onDone(null, result) |
| 158 | + } |
| 159 | + // If `callback` throws, wait for the next mutation, interval, or timeout. |
| 160 | + } catch (error) { |
| 161 | + // Save the most recent callback error to reject the promise with it in the event of a timeout |
| 162 | + lastError = error |
| 163 | + } |
| 164 | + } |
| 165 | + |
| 166 | + function handleTimeout() { |
| 167 | + let error |
| 168 | + if (lastError) { |
| 169 | + error = lastError |
| 170 | + if ( |
| 171 | + !showOriginalStackTrace && |
| 172 | + error.name === 'TestingLibraryElementError' |
| 173 | + ) { |
| 174 | + copyStackTrace(error, stackTraceError) |
| 175 | + } |
| 176 | + } else { |
| 177 | + error = new Error('Timed out in waitFor.') |
| 178 | + if (!showOriginalStackTrace) { |
| 179 | + copyStackTrace(error, stackTraceError) |
| 180 | + } |
| 181 | + } |
| 182 | + onDone(onTimeout(error), null) |
| 183 | + } |
| 184 | + }) |
| 185 | +} |
| 186 | + |
| 187 | +function waitForWrapper(callback, options) { |
| 188 | + // create the error here so its stack trace is as close to the |
| 189 | + // calling code as possible |
| 190 | + const stackTraceError = new Error('STACK_TRACE_MESSAGE') |
| 191 | + return getConfig().asyncWrapper(() => |
| 192 | + waitFor(callback, {stackTraceError, ...options}), |
| 193 | + ) |
| 194 | +} |
| 195 | + |
| 196 | +export {waitForWrapper as waitFor} |
| 197 | + |
| 198 | +/* |
| 199 | +eslint |
| 200 | + max-lines-per-function: ["error", {"max": 200}], |
| 201 | +*/ |
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