react/scripts/jest/matchers/toThrow.js

51 lines
1.5 KiB
JavaScript

'use strict';
// V8 uses a different message format when reading properties of null or undefined.
// Older versions use e.g. "Cannot read property 'world' of undefined"
// Newer versions use e.g. "Cannot read properties of undefined (reading 'world')"
// This file overrides the built-in toThrow() matches to handle both cases,
// enabling the React project to support Node 12-16 without forking tests.
const toThrowMatchers = require('expect/build/toThrowMatchers').default;
const builtInToThrow = toThrowMatchers.toThrow;
// Detect the newer stack format:
let newErrorFormat = false;
try {
null.test();
} catch (error) {
if (error.message.includes('Cannot read properties of null')) {
newErrorFormat = true;
}
}
// Detect the message pattern we need to rename:
const regex = /Cannot read property '([^']+)' of (.+)/;
// Massage strings (written in the older format) to match the newer format
// if tests are currently running on Node 16+
function normalizeErrorMessage(message) {
if (newErrorFormat) {
const match = message.match(regex);
if (match) {
return `Cannot read properties of ${match[2]} (reading '${match[1]}')`;
}
}
return message;
}
function toThrow(value, expectedValue) {
if (typeof expectedValue === 'string') {
expectedValue = normalizeErrorMessage(expectedValue);
} else if (expectedValue instanceof Error) {
expectedValue.message = normalizeErrorMessage(expectedValue.message);
}
return builtInToThrow.call(this, value, expectedValue);
}
module.exports = {
toThrow,
};