module.exports = Transformer;
var traverse = require("../traverse");
var t = require("../types");
var _ = require("lodash");
function Transformer(key, transformer, opts) {
this.transformer = Transformer.normalise(transformer);
this.opts = opts || {};
this.key = key;
}
Transformer.normalise = function (transformer) {
if (_.isFunction(transformer)) {
transformer = { ast: transformer };
}
_.each(transformer, function (fns, type) {
if (type[0] === "_") return;
if (_.isFunction(fns)) fns = { enter: fns };
transformer[type] = fns;
var aliases = t.FLIPPED_ALIAS_KEYS[type];
if (aliases) {
_.each(aliases, function (alias) {
transformer[alias] = fns;
});
}
});
return transformer;
};
Transformer.prototype.astRun = function (file, key) {
var transformer = this.transformer;
var ast = file.ast;
if (transformer.ast && transformer.ast[key]) {
transformer.ast[key](ast, file);
}
};
Transformer.prototype.transform = function (file) {
if (!this.canRun(file)) return;
var transformer = this.transformer;
var ast = file.ast;
this.astRun(file, "enter");
var build = function (exit) {
return function (node, parent, scope) {
var fns = transformer[node.type];
if (!fns) return;
var fn = fns.enter;
if (exit) fn = fns.exit;
if (!fn) return;
return fn(node, parent, file, scope);
};
};
traverse(ast, {
enter: build(),
exit: build(true)
});
this.astRun(file, "exit");
};
Transformer.prototype.canRun = function (file) {
var opts = file.opts;
var key = this.key;
if (key[0] === "_") return true;
var blacklist = opts.blacklist;
if (blacklist.length && _.contains(blacklist, key)) return false;
var whitelist = opts.whitelist;
if (whitelist.length && !_.contains(whitelist, key)) return false;
return true;
};
|