const { humanReadableArgName } = require('./argument.js');
/**
* TypeScript import types for JSDoc, used by Visual Studio Code IntelliSense and `npm run typescript-checkJS`
* https://www.typescriptlang.org/docs/handbook/jsdoc-supported-types.html#import-types
* @typedef { import("./argument.js").Argument } Argument
* @typedef { import("./command.js").Command } Command
* @typedef { import("./option.js").Option } Option
*/
// Although this is a class, methods are static in style to allow override using subclass or just functions.
class Help {
constructor() {
this.helpWidth = undefined;
this.minWidthToWrap = 40;
this.sortSubcommands = false;
this.sortOptions = false;
this.showGlobalOptions = false;
}
/**
* prepareContext is called by Commander after applying overrides from `Command.configureHelp()`
* and just before calling `formatHelp()`.
*
* Commander just uses the helpWidth and the rest is provided for optional use by more complex subclasses.
*
* @param {{ error?: boolean, helpWidth?: number, outputHasColors?: boolean }} contextOptions
*/
prepareContext(contextOptions) {
this.helpWidth = this.helpWidth ?? contextOptions.helpWidth ?? 80;
}
/**
* Get an array of the visible subcommands. Includes a placeholder for the implicit help command, if there is one.
*
* @param {Command} cmd
* @returns {Command[]}
*/
visibleCommands(cmd) {
const visibleCommands = cmd.commands.filter((cmd) => !cmd._hidden);
const helpCommand = cmd._getHelpCommand();
if (helpCommand && !helpCommand._hidden) {
visibleCommands.push(helpCommand);
}
if (this.sortSubcommands) {
visibleCommands.sort((a, b) => {
// @ts-ignore: because overloaded return type
return a.name().localeCompare(b.name());
});
}
return visibleCommands;
}
/**
* Compare options for sort.
*
* @param {Option} a
* @param {Option} b
* @returns {number}
*/
compareOptions(a, b) {
const getSortKey = (option) => {
// WYSIWYG for order displayed in help. Short used for comparison if present. No special handling for negated.
return option.short
? option.short.replace(/^-/, '')
: option.long.replace(/^--/, '');
};
return getSortKey(a).localeCompare(getSortKey(b));
}
/**
* Get an array of the visible options. Includes a placeholder for the implicit help option, if there is one.
*
* @param {Command} cmd
* @returns {Option[]}
*/
visibleOptions(cmd) {
const visibleOptions = cmd.options.filter((option) => !option.hidden);
// Built-in help option.
const helpOption = cmd._getHelpOption();
if (helpOption && !helpOption.hidden) {
// Automatically hide conflicting flags. Bit dubious but a historical behaviour that is convenient for single-command programs.
const removeShort = helpOption.short && cmd._findOption(helpOption.short);
const removeLong = helpOption.long && cmd._findOption(helpOption.long);
if (!removeShort && !removeLong) {
visibleOptions.push(helpOption); // no changes needed
} else if (helpOption.long && !removeLong) {
visibleOptions.push(
cmd.createOption(helpOption.long, helpOption.description),
);
} else if (helpOption.short && !removeShort) {
visibleOptions.push(
cmd.createOption(helpOption.short, helpOption.description),
);
}
}
if (this.sortOptions) {
visibleOptions.sort(this.compareOptions);
}
return visibleOptions;
}
/**
* Get an array of the visible global options. (Not including help.)
*
* @param {Command} cmd
* @returns {Option[]}
*/
visibleGlobalOptions(cmd) {
if (!this.showGlobalOptions) return [];
const globalOptions = [];
for (
let ancestorCmd = cmd.parent;
ancestorCmd;
ancestorCmd = ancestorCmd.parent
) {
const visibleOptions = ancestorCmd.options.filter(
(option) => !option.hidden,
);
globalOptions.push(...visibleOptions);
}
if (this.sortOptions) {
globalOptions.sort(this.compareOptions);
}
return globalOptions;
}
/**
* Get an array of the arguments if any have a description.
*
* @param {Command} cmd
* @returns {Argument[]}
*/
visibleArguments(cmd) {
// Side effect! Apply the legacy descriptions before the arguments are displayed.
if (cmd._argsDescription) {
cmd.registeredArguments.forEach((argument) => {
argument.description =
argument.description || cmd._argsDescription[argument.name()] || '';
});
}
// If there are any arguments with a description then return all the arguments.
if (cmd.registeredArguments.find((argument) => argument.description)) {
return cmd.registeredArguments;
}
return [];
}
/**
* Get the command term to show in the list of subcommands.
*
* @param {Command} cmd
* @returns {string}
*/
subcommandTerm(cmd) {
// Legacy. Ignores custom usage string, and nested commands.
const args = cmd.registeredArguments
.map((arg) => humanReadableArgName(arg))
.join(' ');
return (
cmd._name +
(cmd._aliases[0] ? '|' + cmd._aliases[0] : '') +
(cmd.options.length ? ' [options]' : '') + // simplistic check for non-help option
(args ? ' ' + args : '')
);
}
/**
* Get the option term to show in the list of options.
*
* @param {Option} option
* @returns {string}
*/
optionTerm(option) {
return option.flags;
}
/**
* Get the argument term to show in the list of arguments.
*
* @param {Argument} argument
* @returns {string}
*/
argumentTerm(argument) {
return argument.name();
}
/**
* Get the longest command term length.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {number}
*/
longestSubcommandTermLength(cmd, helper) {
return helper.visibleCommands(cmd).reduce((max, command) => {
return Math.max(
max,
this.displayWidth(
helper.styleSubcommandTerm(helper.subcommandTerm(command)),
),
);
}, 0);
}
/**
* Get the longest option term length.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {number}
*/
longestOptionTermLength(cmd, helper) {
return helper.visibleOptions(cmd).reduce((max, option) => {
return Math.max(
max,
this.displayWidth(helper.styleOptionTerm(helper.optionTerm(option))),
);
}, 0);
}
/**
* Get the longest global option term length.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {number}
*/
longestGlobalOptionTermLength(cmd, helper) {
return helper.visibleGlobalOptions(cmd).reduce((max, option) => {
return Math.max(
max,
this.displayWidth(helper.styleOptionTerm(helper.optionTerm(option))),
);
}, 0);
}
/**
* Get the longest argument term length.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {number}
*/
longestArgumentTermLength(cmd, helper) {
return helper.visibleArguments(cmd).reduce((max, argument) => {
return Math.max(
max,
this.displayWidth(
helper.styleArgumentTerm(helper.argumentTerm(argument)),
),
);
}, 0);
}
/**
* Get the command usage to be displayed at the top of the built-in help.
*
* @param {Command} cmd
* @returns {string}
*/
commandUsage(cmd) {
// Usage
let cmdName = cmd._name;
if (cmd._aliases[0]) {
cmdName = cmdName + '|' + cmd._aliases[0];
}
let ancestorCmdNames = '';
for (
let ancestorCmd = cmd.parent;
ancestorCmd;
ancestorCmd = ancestorCmd.parent
) {
ancestorCmdNames = ancestorCmd.name() + ' ' + ancestorCmdNames;
}
return ancestorCmdNames + cmdName + ' ' + cmd.usage();
}
/**
* Get the description for the command.
*
* @param {Command} cmd
* @returns {string}
*/
commandDescription(cmd) {
// @ts-ignore: because overloaded return type
return cmd.description();
}
/**
* Get the subcommand summary to show in the list of subcommands.
* (Fallback to description for backwards compatibility.)
*
* @param {Command} cmd
* @returns {string}
*/
subcommandDescription(cmd) {
// @ts-ignore: because overloaded return type
return cmd.summary() || cmd.description();
}
/**
* Get the option description to show in the list of options.
*
* @param {Option} option
* @return {string}
*/
optionDescription(option) {
const extraInfo = [];
if (option.argChoices) {
extraInfo.push(
// use stringify to match the display of the default value
`choices: ${option.argChoices.map((choice) => JSON.stringify(choice)).join(', ')}`,
);
}
if (option.defaultValue !== undefined) {
// default for boolean and negated more for programmer than end user,
// but show true/false for boolean option as may be for hand-rolled env or config processing.
const showDefault =
option.required ||
option.optional ||
(option.isBoolean() && typeof option.defaultValue === 'boolean');
if (showDefault) {
extraInfo.push(
`default: ${option.defaultValueDescription || JSON.stringify(option.defaultValue)}`,
);
}
}
// preset for boolean and negated are more for programmer than end user
if (option.presetArg !== undefined && option.optional) {
extraInfo.push(`preset: ${JSON.stringify(option.presetArg)}`);
}
if (option.envVar !== undefined) {
extraInfo.push(`env: ${option.envVar}`);
}
if (extraInfo.length > 0) {
return `${option.description} (${extraInfo.join(', ')})`;
}
return option.description;
}
/**
* Get the argument description to show in the list of arguments.
*
* @param {Argument} argument
* @return {string}
*/
argumentDescription(argument) {
const extraInfo = [];
if (argument.argChoices) {
extraInfo.push(
// use stringify to match the display of the default value
`choices: ${argument.argChoices.map((choice) => JSON.stringify(choice)).join(', ')}`,
);
}
if (argument.defaultValue !== undefined) {
extraInfo.push(
`default: ${argument.defaultValueDescription || JSON.stringify(argument.defaultValue)}`,
);
}
if (extraInfo.length > 0) {
const extraDescription = `(${extraInfo.join(', ')})`;
if (argument.description) {
return `${argument.description} ${extraDescription}`;
}
return extraDescription;
}
return argument.description;
}
/**
* Generate the built-in help text.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {string}
*/
formatHelp(cmd, helper) {
const termWidth = helper.padWidth(cmd, helper);
const helpWidth = helper.helpWidth ?? 80; // in case prepareContext() was not called
function callFormatItem(term, description) {
return helper.formatItem(term, termWidth, description, helper);
}
// Usage
let output = [
`${helper.styleTitle('Usage:')} ${helper.styleUsage(helper.commandUsage(cmd))}`,
'',
];
// Description
const commandDescription = helper.commandDescription(cmd);
if (commandDescription.length > 0) {
output = output.concat([
helper.boxWrap(
helper.styleCommandDescription(commandDescription),
helpWidth,
),
'',
]);
}
// Arguments
const argumentList = helper.visibleArguments(cmd).map((argument) => {
return callFormatItem(
helper.styleArgumentTerm(helper.argumentTerm(argument)),
helper.styleArgumentDescription(helper.argumentDescription(argument)),
);
});
if (argumentList.length > 0) {
output = output.concat([
helper.styleTitle('Arguments:'),
...argumentList,
'',
]);
}
// Options
const optionList = helper.visibleOptions(cmd).map((option) => {
return callFormatItem(
helper.styleOptionTerm(helper.optionTerm(option)),
helper.styleOptionDescription(helper.optionDescription(option)),
);
});
if (optionList.length > 0) {
output = output.concat([
helper.styleTitle('Options:'),
...optionList,
'',
]);
}
if (helper.showGlobalOptions) {
const globalOptionList = helper
.visibleGlobalOptions(cmd)
.map((option) => {
return callFormatItem(
helper.styleOptionTerm(helper.optionTerm(option)),
helper.styleOptionDescription(helper.optionDescription(option)),
);
});
if (globalOptionList.length > 0) {
output = output.concat([
helper.styleTitle('Global Options:'),
...globalOptionList,
'',
]);
}
}
// Commands
const commandList = helper.visibleCommands(cmd).map((cmd) => {
return callFormatItem(
helper.styleSubcommandTerm(helper.subcommandTerm(cmd)),
helper.styleSubcommandDescription(helper.subcommandDescription(cmd)),
);
});
if (commandList.length > 0) {
output = output.concat([
helper.styleTitle('Commands:'),
...commandList,
'',
]);
}
return output.join('\n');
}
/**
* Return display width of string, ignoring ANSI escape sequences. Used in padding and wrapping calculations.
*
* @param {string} str
* @returns {number}
*/
displayWidth(str) {
return stripColor(str).length;
}
/**
* Style the title for displaying in the help. Called with 'Usage:', 'Options:', etc.
*
* @param {string} str
* @returns {string}
*/
styleTitle(str) {
return str;
}
styleUsage(str) {
// Usage has lots of parts the user might like to color separately! Assume default usage string which is formed like:
// command subcommand [options] [command] <foo> [bar]
return str
.split(' ')
.map((word) => {
if (word === '[options]') return this.styleOptionText(word);
if (word === '[command]') return this.styleSubcommandText(word);
if (word[0] === '[' || word[0] === '<')
return this.styleArgumentText(word);
return this.styleCommandText(word); // Restrict to initial words?
})
.join(' ');
}
styleCommandDescription(str) {
return this.styleDescriptionText(str);
}
styleOptionDescription(str) {
return this.styleDescriptionText(str);
}
styleSubcommandDescription(str) {
return this.styleDescriptionText(str);
}
styleArgumentDescription(str) {
return this.styleDescriptionText(str);
}
styleDescriptionText(str) {
return str;
}
styleOptionTerm(str) {
return this.styleOptionText(str);
}
styleSubcommandTerm(str) {
// This is very like usage with lots of parts! Assume default string which is formed like:
// subcommand [options] <foo> [bar]
return str
.split(' ')
.map((word) => {
if (word === '[options]') return this.styleOptionText(word);
if (word[0] === '[' || word[0] === '<')
return this.styleArgumentText(word);
return this.styleSubcommandText(word); // Restrict to initial words?
})
.join(' ');
}
styleArgumentTerm(str) {
return this.styleArgumentText(str);
}
styleOptionText(str) {
return str;
}
styleArgumentText(str) {
return str;
}
styleSubcommandText(str) {
return str;
}
styleCommandText(str) {
return str;
}
/**
* Calculate the pad width from the maximum term length.
*
* @param {Command} cmd
* @param {Help} helper
* @returns {number}
*/
padWidth(cmd, helper) {
return Math.max(
helper.longestOptionTermLength(cmd, helper),
helper.longestGlobalOptionTermLength(cmd, helper),
helper.longestSubcommandTermLength(cmd, helper),
helper.longestArgumentTermLength(cmd, helper),
);
}
/**
* Detect manually wrapped and indented strings by checking for line break followed by whitespace.
*
* @param {string} str
* @returns {boolean}
*/
preformatted(str) {
return /\n[^\S\r\n]/.test(str);
}
/**
* Format the "item", which consists of a term and description. Pad the term and wrap the description, indenting the following lines.
*
* So "TTT", 5, "DDD DDDD DD DDD" might be formatted for this.helpWidth=17 like so:
* TTT DDD DDDD
* DD DDD
*
* @param {string} term
* @param {number} termWidth
* @param {string} description
* @param {Help} helper
* @returns {string}
*/
formatItem(term, termWidth, description, helper) {
const itemIndent = 2;
const itemIndentStr = ' '.repeat(itemIndent);
if (!description) return itemIndentStr + term;
// Pad the term out to a consistent width, so descriptions are aligned.
const paddedTerm = term.padEnd(
termWidth + term.length - helper.displayWidth(term),
);
// Format the description.
const spacerWidth = 2; // between term and description
const helpWidth = this.helpWidth ?? 80; // in case prepareContext() was not called
const remainingWidth = helpWidth - termWidth - spacerWidth - itemIndent;
let formattedDescription;
if (
remainingWidth < this.minWidthToWrap ||
helper.preformatted(description)
) {
formattedDescription = description;
} else {
const wrappedDescription = helper.boxWrap(description, remainingWidth);
formattedDescription = wrappedDescription.replace(
/\n/g,
'\n' + ' '.repeat(termWidth + spacerWidth),
);
}
// Construct and overall indent.
return (
itemIndentStr +
paddedTerm +
' '.repeat(spacerWidth) +
formattedDescription.replace(/\n/g, `\n${itemIndentStr}`)
);
}
/**
* Wrap a string at whitespace, preserving existing line breaks.
* Wrapping is skipped if the width is less than `minWidthToWrap`.
*
* @param {string} str
* @param {number} width
* @returns {string}
*/
boxWrap(str, width) {
if (width < this.minWidthToWrap) return str;
const rawLines = str.split(/\r\n|\n/);
// split up text by whitespace
const chunkPattern = /[\s]*[^\s]+/g;
const wrappedLines = [];
rawLines.forEach((line) => {
const chunks = line.match(chunkPattern);
if (chunks === null) {
wrappedLines.push('');
return;
}
let sumChunks = [chunks.shift()];
let sumWidth = this.displayWidth(sumChunks[0]);
chunks.forEach((chunk) => {
const visibleWidth = this.displayWidth(chunk);
// Accumulate chunks while they fit into width.
if (sumWidth + visibleWidth <= width) {
sumChunks.push(chunk);
sumWidth += visibleWidth;
return;
}
wrappedLines.push(sumChunks.join(''));
const nextChunk = chunk.trimStart(); // trim space at line break
sumChunks = [nextChunk];
sumWidth = this.displayWidth(nextChunk);
});
wrappedLines.push(sumChunks.join(''));
});
return wrappedLines.join('\n');
}
}
/**
* Strip style ANSI escape sequences from the string. In particular, SGR (Select Graphic Rendition) codes.
*
* @param {string} str
* @returns {string}
* @package
*/
function stripColor(str) {
// eslint-disable-next-line no-control-regex
const sgrPattern = /\x1b\[\d*(;\d*)*m/g;
return str.replace(sgrPattern, '');
}
exports.Help = Help;
exports.stripColor = stripColor;