function _copyAndTrimNpmrcFile()

in common/scripts/install-run.js [82:121]

• 31 lines of code
• 8 McCabe index (conditional complexity)

function _copyAndTrimNpmrcFile(sourceNpmrcPath, targetNpmrcPath) {
    console.log(`Transforming ${sourceNpmrcPath}`); // Verbose
    console.log(`  --> "${targetNpmrcPath}"`);
    let npmrcFileLines = fs.readFileSync(sourceNpmrcPath).toString().split('\n');
    npmrcFileLines = npmrcFileLines.map((line) => (line || '').trim());
    const resultLines = [];
    // This finds environment variable tokens that look like "${VAR_NAME}"
    const expansionRegExp = /\$\{([^\}]+)\}/g;
    // Comment lines start with "#" or ";"
    const commentRegExp = /^\s*[#;]/;
    // Trim out lines that reference environment variables that aren't defined
    for (const line of npmrcFileLines) {
        let lineShouldBeTrimmed = false;
        // Ignore comment lines
        if (!commentRegExp.test(line)) {
            const environmentVariables = line.match(expansionRegExp);
            if (environmentVariables) {
                for (const token of environmentVariables) {
                    // Remove the leading "${" and the trailing "}" from the token
                    const environmentVariableName = token.substring(2, token.length - 1);
                    // Is the environment variable defined?
                    if (!process.env[environmentVariableName]) {
                        // No, so trim this line
                        lineShouldBeTrimmed = true;
                        break;
                    }
                }
            }
        }
        if (lineShouldBeTrimmed) {
            // Example output:
            // "; MISSING ENVIRONMENT VARIABLE: //my-registry.com/npm/:_authToken=${MY_AUTH_TOKEN}"
            resultLines.push('; MISSING ENVIRONMENT VARIABLE: ' + line);
        }
        else {
            resultLines.push(line);
        }
    }
    fs.writeFileSync(targetNpmrcPath, resultLines.join(os.EOL));
}