unexpected/lib/createStandardErrorMessage.js

Extensible BDD assertion toolkit

module.exports = function createStandardErrorMessage(output, expect, subject, testDescription, args, options) {
    options = options || {};
    var preamble = 'expected';

    var subjectOutput = output.clone();
    if (subject) {
        subject.call(subjectOutput, subjectOutput);
    }

    var argsOutput = output.clone();
    if (typeof args === 'function') {
        args.call(argsOutput, argsOutput);
    } else {
        if (args.length > 0) {
            args.forEach(function (arg, index) {
                if (0 < index) {
                    argsOutput.text(', ');
                }
                arg.call(argsOutput, argsOutput);
            });
        }
    }

    var subjectSize = subjectOutput.size();
    var argsSize = argsOutput.size();
    var width = preamble.length + subjectSize.width + argsSize.width + testDescription.length;
    var height = Math.max(subjectSize.height, argsSize.height);

    if (options.compactSubject && subjectSize.height > 1) {
        output.error('expected').sp();
        options.compactSubject.call(output, output);
        output.sp();
    } else {
        output.error(preamble);
        if (subjectSize.height > 1) {
            output.nl();
        } else {
            output.sp();
        }
        output.append(subjectOutput);
        if (subjectSize.height > 1 || (height === 1 && width > output.preferredWidth)) {
            output.nl();
        } else {
            output.sp();
        }
    }

    output.error(testDescription);

    if (argsSize.height > 1) {
        output.nl();
    } else if (argsSize.width > 0) {
        output.sp();
    }

    output.append(argsOutput);

    return output;
};