Comparison with string doesn't work in Jenkins pipeline

Question

Any idea why the IF-ELSE below works

def checkPrValidity() {
    wordCountStr = sh returnStdout: true, script: 'git diff --ignore-space-at-eol $target_branch..PRbranch src | wc -l' 
    wordCount = wordCountStr.toInteger() //force conversion to int data type 
    if (wordCount == 0) {
        return false;
    } else {
        println("This is a valid PR, continue the job execution")
        return true;
    }
}

while the one below doesn't

def checkPrValidity() {
    wordCountStr = sh returnStdout: true, script: 'git diff --ignore-space-at-eol $target_branch..PRbranch src | wc -l'
    if (wordCountStr == '0') {
        return false;
    } else {
        println("This is a valid PR, continue the job execution")
        return true;
    }
}

Why do i need to specifically convert a string to Integer, while it fails to compare it as a string data type?

Answer 1

Try to add .trim() to your sh. Because in output there can be new line, which prevents correct comparison.