corona-test.js

// Run this script on this page https://www.worldometers.info/coronavirus/
const c = $$('#main_table_countries_today tr').map(el => ({
  country: $(el).find('td:nth-of-type(2)').text(),
  totalCases: $(el).find('td:nth-of-type(3)').text(),
  testsPerMillion: $(el).find('td:nth-of-type(13)').text(),
  tests: $(el).find('td:nth-of-type(12)').text(),
}))

const toNumber = ({ totalCases, tests, testsPerMillion, country }) => ({
  country,
  tests: parseInt(tests.replace(/,/g, '')),
  totalCases: parseInt(totalCases.replace(/,/g, '')),
  testsPerMillion: parseInt(testsPerMillion.replace(/,/g, '')),
})

const filterOutUnWanted = ({ country }) => (
  // We dont want data for 'World', and the continents. Just countries
  // Intrestingly Continents have a '\n' character
  country && !['World', 'Total:'].includes(country) && !country.includes('\n')
)

const cases = c.filter(filterOutUnWanted).map(toNumber)

const greaterThan5k = cases.filter(c => c.totalCases && c.totalCases > 5000)

const greaterThan5kAndHasTestsPerMillion = greaterThan5k.filter(({ testsPerMillion, tests }) => testsPerMillion && tests)

const sumOfTestsPerMillion = greaterThan5kAndHasTestsPerMillion.reduce((total, c) => c.testsPerMillion + total, 0)

const averageTestPerMillion = sumOfTestsPerMillion / greaterThan5kAndHasTestsPerMillion.length

const testsPerMillion = greaterThan5kAndHasTestsPerMillion.map(({ testsPerMillion, country }) => ({
  testsPerMillion,
  country,
}))

testsPerMillion.sort((a, b) => a.testsPerMillion - b.testsPerMillion)

const testsToPositiveRatio = greaterThan5kAndHasTestsPerMillion.map(c => ({
  ratio: c.totalCases / c.tests,
  country: c.country
}))

testsToPositiveRatio.sort((a, b) => a.ratio - b.ratio)
console.log(
`No of countries with cases: ${cases.length}
Greater than 5k Cases: ${greaterThan5k.length}
Greater Than 5k Cases And Has Tests Per Million: ${greaterThan5kAndHasTestsPerMillion.length}`
)

console.log(`Average tests per million: ${averageTestPerMillion}`)
console.log()
console.log('Countries with min tests per million')
testsPerMillion.slice(0, 5).forEach(({ country, testsPerMillion }) => {
  console.log(`Country: ${country}, Tests Per million: ${testsPerMillion}`)
})
console.log()
console.log('Countries with high tests per million')
testsPerMillion.reverse().slice(0, 5).forEach(({ country, testsPerMillion }) => {
  console.log(`Country: ${country}, Tests Per million: ${testsPerMillion}`)
})
console.log()
console.log('Countries with low positivity ratio')
testsToPositiveRatio.slice(0, 5).forEach(({ country, ratio }) => {
  console.log(`Country: ${country}, Ratio: ${ratio}`)
})
console.log()
console.log('Countries with high positivity ratio')
testsToPositiveRatio.reverse().slice(0, 5).forEach(({ country, ratio }) => {
  console.log(`Country: ${country}, Ratio: ${ratio}`)
})

const nigeriaPRatio = testsToPositiveRatio.find(({ country }) => country === "Nigeria")
console.log("Nigeria's ratio: ", nigeriaPRatio.ratio)