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style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><h1 style="--title-fw:var(--mantine-h1-font-weight);--title-lh:var(--mantine-h1-line-height);--title-fz:var(--mantine-h1-font-size)" class="m_8a5d1357 mantine-Title-root" data-order="1">Course “JS: Advanced Testing”</h1></div></div></div><style data-mantine-styles="inline">.__m__-_R_1iub_{width:100%;}@media(min-width: 62em){.__m__-_R_1iub_{width:66%;}}</style><div style="margin-bottom:var(--mantine-spacing-xl)" class="__m__-_R_1iub_"><div style="margin-bottom:var(--mantine-spacing-lg)" class=""></div><div style="margin-top:var(--mantine-spacing-lg)" class="mantine-hidden-from-md"><div style="--stack-gap:var(--mantine-spacing-xs);--stack-align:stretch;--stack-justify:flex-start" class="m_6d731127 mantine-Stack-root"><a 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mantine-Grid-inner"><style data-mantine-styles="inline">.__m__-_R_dmiub_{--col-flex-grow:auto;--col-flex-basis:100%;--col-max-width:100%;}@media(min-width: 62em){.__m__-_R_dmiub_{--col-flex-grow:auto;--col-flex-basis:66.66666666666667%;--col-max-width:66.66666666666667%;}}</style><div class="m_96bdd299 mantine-Grid-col __m__-_R_dmiub_"><div style="margin-bottom:var(--mantine-spacing-xl);padding-inline:var(--mantine-spacing-xl);padding-block:var(--mantine-spacing-lg)" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><p style="margin-bottom:var(--mantine-spacing-md);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">What's included</p><style data-mantine-styles="inline">.__m__-_R_ajddmiub_{--sg-spacing-x:var(--mantine-spacing-xs);--sg-spacing-y:var(--mantine-spacing-xs);--sg-cols:1;}@media(min-width: 48em){.__m__-_R_ajddmiub_{--sg-cols:2;}}</style><div class="m_2415a157 mantine-SimpleGrid-root __m__-_R_ajddmiub_"><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_1mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>10 lessons (video and/or text)</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_2mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>9 exercises in the simulator</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_3mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>24 verification tests</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_4mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>Self-study tasks</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_5mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>Extra materials</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_6mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div>10 extended materials</div></div></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Description</h2><div class="m_d08caa0 mantine-Typography-root"><p>Testing real applications is much more complicated than just calling functions. There are a lot of network requests to external resources, interaction with the file system, asynchronous code, and external libraries with their tricks. It all comes down to a good understanding of side effects and effective ways to isolate and manage them.</p></div></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">You will learn</h2><ul class="m_abbac491 mantine-List-root" data-type="none"><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Freely test even those applications that interact a lot with the external environment</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Test code that actively works with the file system</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Apply polymorphism to replace the implementation of code that is inconvenient in testing</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Use stubs and mocking for their intended purpose</span></div></li></ul></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Syllabus</h2><table style="--table-vertical-spacing:calc(0.4375rem * var(--mantine-scale))" class="m_b23fa0ef mantine-Table-table"><tbody class="m_b2404537 mantine-Table-tbody"><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">1</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/init/theory_unit">Introduction</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore the course and its objectives</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/errors/theory_unit">Error testing</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to properly test code that throws exceptions</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">3</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/fixtures/theory_unit">Fixtures</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to properly prepare data for tests</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">4</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/side-effects/theory_unit">Side effects</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Understand why testing is difficult</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">5</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/files/theory_unit">Testing code that interacts with files</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to properly restore the environment. Explore the virtual file system.</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">6</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/elimination-of-side-effects/theory_unit">Dependency Inversion</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn to eliminate side effects with polymorphism</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">7</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/stub/theory_unit">Testing HTTP Requests</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn stubbing</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">8</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/monkey-patching/theory_unit">Monkey patching</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to use prototypes to your advantage</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">9</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/mocking/theory_unit">Mocking</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore mocking and learn how to distinguish them from stubs</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">10</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-advanced-testing/lessons/property-based-testing/theory_unit">Property-based testing</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore a property-based approach to testing</p></td></tr></tbody></table></div><div class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Recommended programs</h2><style data-mantine-styles="inline">.__m__-_R_avddmiub_{--carousel-slide-gap:var(--mantine-spacing-xs);--carousel-slide-size:70%;}@media(min-width: 36em){.__m__-_R_avddmiub_{--carousel-slide-gap:var(--mantine-spacing-xl);--carousel-slide-size:50%;}}</style><div style="--carousel-control-size:calc(2.5rem * var(--mantine-scale));--carousel-controls-offset:var(--mantine-spacing-sm);margin-bottom:var(--mantine-spacing-lg);padding-block:var(--mantine-spacing-sm);background:var(--app-color-surface)" class="m_17884d0f mantine-Carousel-root responsiveClassName" data-orientation="horizontal" data-include-gap-in-size="true"><div class="m_39bc3463 mantine-Carousel-controls" data-orientation="horizontal"><button class="mantine-focus-auto m_64f58e10 mantine-Carousel-control m_87cf2631 mantine-UnstyledButton-root" type="button" data-inactive="true" data-type="previous" tabindex="-1"><svg viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" 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