Rigorous trainer selection
Each trainer is validated on three criteria: hands-on field expertise, proven pedagogy and alignment with your industry.
- Triple validation: technical, pedagogical, sectoral.
- Minimum rating 4.8/5 over the last 12 sessions.
Describe your need, get a tailored program and a pre-filled quote in 3 min. A 100% free call with an advisor.
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Dive into advanced mocking techniques with jest.mock to simulate external modules, create interactive spies via jest.fn to track function calls, apply these tools to concrete REST API and database cases, perform practical exercises on your existing codebase, produce robust isolated tests with argument validation and custom returns, end with a collective code review to identify common pitfalls and optimize professional reliability.
Master tests for asynchronous code by configuring jest.useFakeTimers to speed up timeouts, test promises and async/await with precise expect assertions, integrate react-testing-library for realistic React tests, simulate network latency and API error scenarios on full-stack applications, develop enduring test suites through hands-on exercises, generate detailed performance reports, and consolidate your skills on a main project for immediate team productivity.
Configure jest.config.js for multi-project environments and mandatory coverage thresholds, analyze HTML coverage reports to target weak areas, integrate Jest with GitHub Actions and Jenkins via practical CI/CD pipelines, test Node.js microservices with 90% thresholds, conduct workshops on optimizing execution times through parallelism, produce coverage badges for your repos, and deploy a professional configuration ready for enterprise use with a focus on scalability and maintenance.
Create intelligent snapshots and custom matchers to validate complex JSON structures or UI, integrate Jest with Enzyme and Testing Library for advanced component tests, apply best practice patterns to a complete main project (authentication, state management), perform a simulated production deployment with e2e tests, evaluate overall performance via profiling tools, finalize with a presentation and expert code review, leave with certifying skills ready to transform your development processes in enterprise settings.
The Training Jest - Mastering High-Performance Unit Tests program is delivered onsite or remote (blended-learning, virtual classroom, remote presence). At Learni, an industry-certified training organization, every program is built to maximize skills acquisition regardless of the chosen format.
The trainer alternates between demonstrative, interrogative and active methods (through hands-on labs and/or scenarios). This pedagogical approach guarantees concrete learning that's immediately applicable at work.
Equipment required
For the smooth delivery of the Training Jest - Mastering High-Performance Unit Tests program, the following equipment is required:
For intra-company training on a site outside Learni, the client commits to providing all required teaching materials (computers, internet, etc.) for the smooth delivery of the program in line with the prerequisites in the communicated program.
Skills assessment methods
Assessment of skills acquired during the Training Jest - Mastering High-Performance Unit Tests program is performed through:
Program accessibility
Learni is committed to making its programs accessible. All our programs are accessible to people with disabilities. Our teams are available to adapt the pedagogical methods to your specific needs. Please contact us for any adjustment request.
Enrollment terms and lead times
Registration is possible up to 48 business hours before the start of training. All our programs are built for corporate L&D budgets and delivered onsite or remotely.
The Learni story
Founded by engineers and learning experts, Learni's mission is to make high-impact tech training accessible to teams everywhere. We work remotely with organizations across the US and Canada, in your time zone, to help teams upskill fast.
Before, during, after: we frame the brief, introduce the trainer, tailor the content and measure impact. You stay in control from kickoff to wrap-up.
Rigorous trainer selection
Each trainer is validated on three criteria: hands-on field expertise, proven pedagogy and alignment with your industry.
You meet the trainer beforehand
30-minute video call between you and the selected trainer to validate the fit, adjust content and clear any final doubts.
Content tailored to your context
No recycled slides. The syllabus is reworked from your real cases: tools, constraints, vocabulary, ongoing projects.
Continuous quality follow-up
Live evaluations, 30/90/180-day check-ins and a consolidation plan. If the impact misses the mark, we rework it.
A simple promise: you don't pay to discover the trainer on day one. Everything is validated upfront, by you.

A school kit donated to a child for every training booked
To fight inequalities in access to education, Learni donates a complete school kit to a child in need for every training booked. You build your skills, a child heads back to school.
30 minutes with a learning advisor. No commitment. No sales pitch dressed up as a demo.
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