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 mastering Jest, 40% of bugs escape basic tests, costing 20h/week in urgent debugging according to Stack Overflow.
Projects delivered with 30% delays due to invisible regressions, customer satisfaction dropping 25% per Gartner.
Teams frustrated by slow and flaky tests, developer turnover +15%.
Investing 35h today avoids 500h of annual losses, secures your deployments, and boosts your career employability by 20%.
Don't let chaos test your patience.
Dive into Jest installation and custom configuration via CLI and jest.config.js, test immediately with advanced matchers like toMatchObject or toHaveLength, complete exercises on real-world JSON data validation cases, generate your first detailed test reports, alternating quick theory and intensive practice for immediate skill ramp-up.
Create manual mocks with jest.fn and automatic ones via jest.mock to simulate external APIs, spy on functions to verify calls and returns, apply to concrete cases like mocked HTTP fetch, generate mock snapshots for smooth maintenance, experience the thrill of isolated tests boosting your productivity from day one.
Master async tests with expect.assertions and resolvers, capture snapshots for React components or complex objects, handle async errors via try/catch, practice on real Node.js app scenarios, produce robust production-ready test suites, with a pedagogical flow that makes every exercise engaging and practical.
Analyze coverage with jest --coverage and enforce 90% thresholds, optimize slow tests via --watch and bail, integrate setup/teardown hooks, work on an open-source project to boost real coverage, receive live feedback for immediate gains, transform your tests into a strategic asset.
Integrate Jest into GitHub Actions for smooth CI/CD, refactor an existing test suite for maintainability, develop a complete final project using all tools covered, present your deliverables and receive certification, end as a hero of reliable testing, ready to excel in your team.
The Jest Training - Master Advanced JavaScript Unit Testing 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 Jest Training - Master Advanced JavaScript Unit Testing 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 Jest Training - Master Advanced JavaScript Unit Testing 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.
Registration is possible up to 48 business hours before the start of training. All our programs are eligible for corporate training budgets and employer-funded plans.
« 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.
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement JavaScriptIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Développement WebIndustry-certified
Cloud ComputingIndustry-certified
Cloud ComputingIndustry-certified
Cloud ComputingIndustry-certified
Cloud ComputingIndustry-certified
Cloud ComputingIndustry-certified
Cloud ComputingIndustry-certified
DevOpsIndustry-certified
DevOpsIndustry-certified
DevOpsIndustry-certified
DevOpsIndustry-certified
DevOpsIndustry-certified
DevOpsIndustry-certified30 minutes with a learning advisor. No commitment. No sales pitch dressed up as a demo.