// If you think you need to add an exception here, please ask Hixie (but he'll say no).
expect(option.name,matches(_allowedArgumentNamePattern),reason:'$_header$command--${option.name}" is not a valid name for a command line argument. (Is it all lowercase?)');
expect(option.hide,isFalse,reason:'${_header}Help for $command--${option.name}" is always hidden. $_needHelp');
expect(option.help,isNotNull,reason:'${_header}Help for $command--${option.name}" has null help. $_needHelp');
expect(option.help,isNotEmpty,reason:'${_header}Help for $command--${option.name}" has empty help. $_needHelp');
expect(option.help,isNot(matches(_bannedLeadingPatterns)),reason:'${_header}A line in the help for $command--${option.name}" starts with a lowercase letter. For stylistic consistency, all help messages must start with a capital letter.');
expect(option.help,isNot(startsWith('(Deprecated')),reason:'${_header}Help for $command--${option.name}" should start with lowercase "(deprecated)" for consistency with other deprecated commands.');
expect(option.help,isNot(startsWith('(Required')),reason:'${_header}Help for $command--${option.name}" should start with lowercase "(required)" for consistency with other deprecated commands.');
expect(option.help,isNot(contains('?')),reason:'${_header}Help for $command--${option.name}" has a question mark. Generally we prefer the passive voice for help messages.');
expect(option.help,isNot(contains('Note:')),reason:'${_header}Help for $command--${option.name}" uses "Note:". See our style guide entry about "empty prose".');
expect(option.help,isNot(contains('Note that')),reason:'${_header}Help for $command--${option.name}" uses "Note that". See our style guide entry about "empty prose".');
expect(option.help,isNot(matches(_bannedQuotePatterns)),reason:'${_header}Help for $command--${option.name}" uses single quotes or backticks instead of double quotes in the help message. For consistency we use double quotes throughout.');
expect(option.help,isNot(matches(_questionablePatterns)),reason:'${_header}Help for $command--${option.name}" may have a typo. (If it does not you may have to update args_test.dart, sorry. Search for "_questionablePatterns")');
if(option.defaultsTo!=null){
expect(option.help,isNot(contains('Default')),reason:'${_header}Help for $command--${option.name}" mentions the default value but that is redundant with the defaultsTo option which is also specified (and preferred).');
}
expect(option.help,isNot(matches(_bannedArgumentReferencePatterns)),reason:'${_header}Help for $command--${option.name}" contains the string "--" in an unexpected way. If it\'s trying to mention another argument, it should be quoted, as in "--foo".');
for(finalStringlineinoption.help.split('\n')){
if(!line.startsWith(' ')){
expect(line,isNot(contains(' ')),reason:'${_header}Help for $command--${option.name}" has excessive whitespace (check e.g. for double spaces after periods or round line breaks in the source).');
expect(line,matches(_allowedTrailingPatterns),reason:'${_header}A line in the help for $command--${option.name}" does not end with the expected period that a full sentence should end with. (If the help ends with a URL, place it after a colon, don\'t leave a trailing period; if it\'s sample code, prefix the line with four spaces.)');
}
}
expect(option.help,isNot(endsWith(':')),reason:'${_header}Help for $command--${option.name}" ends with a colon, which seems unlikely to be correct.');
// TODO(ianh): add some checking for embedded URLs to make sure we're consistent on how we format those.
// TODO(ianh): arguably we should ban help text that starts with "Whether to..." since by definition a flag is to enable a feature, so the "whether to" is redundant.
// TODO(ianh): consider looking for strings that use the term "URI" instead of "URL".
