check.js

var lint = require("./jshint.js");
var identRegex = /[a-zA-Z\$_0-9]/;

function startRegex(arr) {
    return RegExp("^(" + arr.join("|") + ")");
}

var disabledWarningsRe = startRegex([
    "Bad for in variable '(.+)'.",
    'Missing "use strict"']);
var errorsRe = startRegex([
    "Unexpected",
    "Expected ",
    "Confusing (plus|minus)",
    "\\{a\\} unterminated regular expression",
    "Unclosed ",
    "Unmatched ",
    "Unbegun comment",
    "Bad invocation",
    "Missing space after",
    "Missing operator at"]);
var infoRe = startRegex([
    "Expected an assignment",
    "Bad escapement of EOL",
    "Unexpected comma",
    "Unexpected space",
    "Missing radix parameter.",
    "A leading decimal point can",
    "\\['{a}'\\] is better written in dot notation.",
    "'{a}' used out of scope"]);

function isValidJS(str) {
    try {
        // evaluated code can only create variables in this function
        eval("throw 0;" + str);
    } catch (e) {
        if (e === 0) return true;
    }
    return false;
}

function findIdentifierRange(line, startColumn) {
    var pos = {
        column: startColumn,
        endColumn: undefined
    };
    if (!line) {
        return pos;
    }
    // Look backwards
    for (var i = startColumn; i >= 0; i--) {
        var ch = line[i];
        if (identRegex.exec(ch)) {
            pos.column = i;
            break;
        }
    }
    for (var i = pos.column; i >= 0; i--) {
        var ch = line[i];
        if (!identRegex.exec(ch)) {
            pos.column = i + 1;
            break;
        }
    }
    // And ahead
    for (var i = pos.column; i <= line.length; i++) {
        var ch = line[i];
        if (!identRegex.exec(ch) || !ch) {
            if (i !== pos.column) {
                pos.endColumn = i;
            }
            break;
        }
    }
    return pos;
}


/**
 * Required inputs: text
 */
module.exports = function(info) {
    var value = info.inputs.text;
    value = value.replace(/^#!.*\n/, "\n");
    if (!value) {
        return [];
    }
    var lines = value.split("\n");
    var errors = [];

    // js hint reports many false errors
    // report them as error only if code is actually invalid
    var maxErrorLevel = isValidJS(value) ? "warning" : "error";

    var globals;
    if (info.options) {
        globals = info.options.globals;
    }

    // var start = new Date();
    lint(value, info.options, globals);
    var results = lint.errors;

    for (var i = 0; i < results.length; i++) {
        var error = results[i];
        if (!error) continue;
        var raw = error.raw;
        var type = "warning";

        if (raw == "Missing semicolon.") {
            var str = error.evidence.substr(error.character);
            str = str.charAt(str.search(/\S/));
            if (maxErrorLevel == "error" && str && /[\w\d{(['"]/.test(str)) {
                error.reason = 'Missing ";" before statement';
                type = "error";
            } else {
                type = "info";
            }
        } else if (disabledWarningsRe.test(raw)) {
            continue;
        } else if (infoRe.test(raw)) {
            type = "info";
        } else if (errorsRe.test(raw)) {
            type = maxErrorLevel;
        } else if (raw == "'{a}' is not defined.") {
            type = "warning";
        } else if (raw == "'{a}' is defined but never used.") {
            type = "info";
        }

        var line = lines[error.line - 1];

        if (line) {
            // JSHint automatically converts tabs (\t) into 4 characters,
            // whereas in the source file it's only one, so let's remove
            // all "bonus" spaces (3 per tab) from the character position.
            var match = line.match(/\t/g);
            if (match) {
                error.character -= match.length * 3;
            }
        }

        var pos = findIdentifierRange(line, error.character - 1);
        // console.log("Error", error, pos);

        errors.push({
            row: error.line - 1,
            column: pos.column,
            endColumn: pos.endColumn,
            text: error.reason,
            type: type,
            raw: raw
        });
    }
    return errors;
};