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.
Founded by passionate learning and innovation experts, Learni's mission is to make professional training accessible to everyone, anywhere in the world. Our team operates in major hubs — London, New York, Boston — and internationally, to support talents and organizations in upskilling.
Don't let this gap widen
Without this upskilling, your team accumulates a technological gap that translates directly into productivity loss.
Organizations that don't train their talents on key topics see their competitiveness drop.
Every quarter without training is a gap widening with competitors who invest.
The cost of inaction quickly exceeds that of well-targeted training.
Dive into Jest by installing the environment via npm, configure jest.config.js for your Node or React project, run your first tests with describe and it, practice on concrete cases like testing pure functions, generate coverage reports, and produce an initial functional test report, while exploring watch mode for rapid iterations.
Write complete suites with async/await, test promises and errors via try/catch, master toEqual for complex objects, apply toMatchSnapshot on React components, complete exercises on mocked APIs, and validate your tests with 80% coverage, boosting your confidence in robust code.
Simulate external modules with jest.mock, create spies to track function calls, test timer and fetch interactions via jest.useFakeTimers, practice on real cases like API services, generate automated mocks for dependencies, and integrate into a personal project, making your tests independent and fast.
Speed up tests with --runInBand or workers, structure via beforeEach/afterAll, migrate from Mocha to Jest, optimize for large projects via bail and testTimeout, apply patterns to legacy code, produce before/after benchmarks, and prepare GitHub Actions integration for smooth execution.
Develop a complete e-commerce project with 100+ tests, integrate into CI/CD pipeline, debug via --debug and breakpoints, apply ESLint rules for clean code, share coverage via HTML reports, and conclude with peer-to-peer review, taking away a concrete portfolio and production-ready skills.
The Training Jest - Master JS Unit Tests in 5 Days program is delivered onsite or remote (blended-learning, e-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.
For the smooth delivery of the Training Jest - Master JS Unit Tests in 5 Days 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.
Assessment of skills acquired during the Training Jest - Master JS Unit Tests in 5 Days program is performed through:
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.
Learni programs are available inter-company and intra-company, onsite or remote. Enrollments are possible up to 48 business hours before the program starts. Our programs are eligible for corporate funding paths. Contact us to discuss your training project and funding options.
« cool, j'ai appris des trucs »
« j'etais perdu au debut mais Ramy Saharaoui m'a pas laché, il a pris le temps. merci vraiment »
« la formation dev etait intense mais grave bien. merci Anthony Khelil »
« 😊👍 »
« bien 👍 »
« Allan Busi t'es au top, continue comme ça. formation géniale »
« cool, j'ai appris des trucs »
« j'etais perdu au debut mais Ramy Saharaoui m'a pas laché, il a pris le temps. merci vraiment »
« la formation dev etait intense mais grave bien. merci Anthony Khelil »
« 😊👍 »
« bien 👍 »
« Allan Busi t'es au top, continue comme ça. formation géniale »
« cool, j'ai appris des trucs »
« j'etais perdu au debut mais Ramy Saharaoui m'a pas laché, il a pris le temps. merci vraiment »
« la formation dev etait intense mais grave bien. merci Anthony Khelil »
« 😊👍 »
« bien 👍 »
« Allan Busi t'es au top, continue comme ça. formation géniale »
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.
Each trainer is validated on three criteria: hands-on field expertise, proven pedagogy and alignment with your industry.
30-minute video call between you and the selected trainer to validate the fit, adjust content and clear any final doubts.
No recycled slides. The syllabus is reworked from your real cases: tools, constraints, vocabulary, ongoing projects.
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.
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Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
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Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Langages de ProgrammationIndustry-certified
Langages de ProgrammationIndustry-certified
Langages de ProgrammationIndustry-certified
Langages de ProgrammationIndustry-certified
Langages de ProgrammationIndustry-certified
Langages de ProgrammationIndustry-certified
Data ScienceIndustry-certified
Data ScienceIndustry-certified
Data ScienceIndustry-certified
Data ScienceIndustry-certified
Data ScienceIndustry-certified
Data ScienceIndustry-certified30 minutes with a learning advisor. No commitment. No sales pitch dressed up as a demo.