Jacoco is a tool used to generate detailed reports on code coverage. It is an essential part of a software developer’s toolkit, since it helps determine what portions of a project’s code were actually tested. Jacoco produces HTML reports that display code coverage information in an easy to read format.
Context
After running the Jacoco report generator we can open it and see the coverage results. There are some results the I wanted to know, for example, how many packages contain uncovered classes and how many contain coverage under a given threshold, in this case, I used 60%. So I build a script to count them and print in the browser’s console. So, step into Jacoco’s report tab and paste this script in your browser console to execute it and see the output
Script
const table = document.getElementById("coveragetable");
const row = table.rows;
let uncoveredPackages = 0;
let columnFound = false; // the instructions coverage
let thresholdCoverage = 60;
let packagesUnderThreshold = 0;
let totalPackages = 0;
let i = 0;
while (!columnFound && i < row[0].cells.length) {
// Getting the text of columnName
const str = row[0].cells[i].innerHTML;
if (str.search("Cov.") != -1) {
if (!columnFound) {
// this is the first column with coverage for instructions the next "Cov." column is the one for branches
columnFound = true;
// iterate every row but the head and foot
for (let j = 1; j < row.length - 1; j++) {
const content = row[j].cells[i].innerHTML;
const cov = parseFloat(content);
totalPackages++;
if (cov === 0) {
uncoveredPackages++;
}
if (cov < thresholdCoverage) {
packagesUnderThreshold++;
}
}
}
}
i++;
}
console.log(`total packages: ${totalPackages}`);
console.log(`uncovered packages: ${uncoveredPackages}`);
console.log(`packages under ${thresholdCoverage}%: ${packagesUnderThreshold}`);
Output
total packages: 226
uncovered packages: 60
packages under 60%: 157
