'use strict';
/**
* @param typeMap [Object] Map of MIME type -> Array[extensions]
* @param ...
*/
function Mime() {
this._types = Object.create(null);
this._extensions = Object.create(null);
for (let i = 0; i < arguments.length; i++) {
this.define(arguments[i]);
}
this.define = this.define.bind(this);
this.getType = this.getType.bind(this);
this.getExtension = this.getExtension.bind(this);
}
/**
* Define mimetype -> extension mappings. Each key is a mime-type that maps
* to an array of extensions associated with the type. The first extension is
* used as the default extension for the type.
*
* e.g. mime.define({'audio/ogg', ['oga', 'ogg', 'spx']});
*
* If a type declares an extension that has already been defined, an error will
* be thrown. To suppress this error and force the extension to be associated
* with the new type, pass `force`=true. Alternatively, you may prefix the
* extension with "*" to map the type to extension, without mapping the
* extension to the type.
*
* e.g. mime.define({'audio/wav', ['wav']}, {'audio/x-wav', ['*wav']});
*
*
* @param map (Object) type definitions
* @param force (Boolean) if true, force overriding of existing definitions
*/
Mime.prototype.define = function(typeMap, force) {
for (let type in typeMap) {
let extensions = typeMap[type].map(function(t) {
return t.toLowerCase();
});
type = type.toLowerCase();
for (let i = 0; i < extensions.length; i++) {
const ext = extensions[i];
// '*' prefix = not the preferred type for this extension. So fixup the
// extension, and skip it.
if (ext[0] === '*') {
continue;
}
if (!force && (ext in this._types)) {
throw new Error(
'Attempt to change mapping for "' + ext +
'" extension from "' + this._types[ext] + '" to "' + type +
'". Pass `force=true` to allow this, otherwise remove "' + ext +
'" from the list of extensions for "' + type + '".'
);
}
this._types[ext] = type;
}
// Use first extension as default
if (force || !this._extensions[type]) {
const ext = extensions[0];
this._extensions[type] = (ext[0] !== '*') ? ext : ext.substr(1);
}
}
};
/**
* Lookup a mime type based on extension
*/
Mime.prototype.getType = function(path) {
path = String(path);
let last = path.replace(/^.*[/\\]/, '').toLowerCase();
let ext = last.replace(/^.*\./, '').toLowerCase();
let hasPath = last.length < path.length;
let hasDot = ext.length < last.length - 1;
return (hasDot || !hasPath) && this._types[ext] || null;
};
/**
* Return file extension associated with a mime type
*/
Mime.prototype.getExtension = function(type) {
type = /^\s*([^;\s]*)/.test(type) && RegExp.$1;
return type && this._extensions[type.toLowerCase()] || null;
};
module.exports = Mime;