function checkTranslationKeysUsageInFiles(): IError[] {
    const files = fileList(CSON_ROOT_FOLDER);
    const allVariables = flattenJSONToI18nVariables(
    flattenJSON(readCSONFile('en')), );

    const fileVariables = getVariablesFromFiles();

    let errors: IError[] = [];
    for (const {
        filepathRelative, root, variables
    }
    of fileVariables) {
        for (const variable of variables) {
            const nameWithRoot = `$ {
                root
            }.$ {
                variable.name
            }`;

            // check that used var is defined in CSON
            if (!allVariables.hasOwnProperty(nameWithRoot)) {
                errors = [...errors,
                {
                    // tslint:disable-next-line:max-line-length
                    message: `"${variable.name}"
                    translation key is used in the "${filepathRelative}",
                    but not listed in CSON file.Please add listed variables to en.cson and
                    try again`,
                }];
                continue;
            }

            // check params usage
            const csonVarParams = extractCSONVariableParams(allVariables[nameWithRoot]).sort();
            const usedParams = variable.params.map(param = > param.name).sort();

            if (!isEqual(csonVarParams, usedParams)) {
                errors = [...errors,
                {
                    // tslint:disable-next-line:max-line-length
                    message: `Translation variable params does not match.file: "${filepathRelative}";
                    var: $ {
                        variable.name
                    };\nExpected params: $ {
                        JSON.stringify(csonVarParams)
                    };
                    Actual params: $ {
                        JSON.stringify(usedParams)
                    }
                }`,
                }];
        }
    }
}

return errors;
}
Setting Validate Copy Format