const libCoverage = require('istanbul-lib-coverage'); const { createReporter } = require('istanbul-api'); const coverage_1 = require('./.nyc_output/coverage.json'); const coverage_2 = require('./.nyc_output/coverage2.json'); const normalizeJestCoverage = (obj) => { const result = obj; Object.entries(result).forEach(([k, v]) => { if (v.data) result[k] = v.data; }); return result; }; const map = libCoverage.createCoverageMap(); map.merge(normalizeJestCoverage(coverage_1)); map.merge(normalizeJestCoverage(coverage_2)); const reporter = createReporter(); reporter.addAll(['html', 'json', 'lcov', 'text']); reporter.write(map);