blob: 97407ffaa4172712ac509bd9bfe520c2673a44c5 [file] [log] [blame]
/* vim: set sw=4 sts=4 : */
(function () {
var estraverse = require('estraverse');
var parser = require('./parser');
var isArray = Array.isArray || function isArray(array) {
return {}.toString.call(array) === '[object Array]';
};
var LEFT_SIDE = {};
var RIGHT_SIDE = {};
function esqueryModule() {
/**
* Get the value of a property which may be multiple levels down in the object.
*/
function getPath(obj, key) {
var i, keys = key.split(".");
for (i = 0; i < keys.length; i++) {
if (obj == null) { return obj; }
obj = obj[keys[i]];
}
return obj;
}
/**
* Determine whether `node` can be reached by following `path`, starting at `ancestor`.
*/
function inPath(node, ancestor, path) {
var field, remainingPath, i;
if (path.length === 0) { return node === ancestor; }
if (ancestor == null) { return false; }
field = ancestor[path[0]];
remainingPath = path.slice(1);
if (isArray(field)) {
for (i = 0, l = field.length; i < l; ++i) {
if (inPath(node, field[i], remainingPath)) { return true; }
}
return false;
} else {
return inPath(node, field, remainingPath);
}
}
/**
* Given a `node` and its ancestors, determine if `node` is matched by `selector`.
*/
function matches(node, selector, ancestry) {
var path, ancestor, i, l, p;
if (!selector) { return true; }
if (!node) { return false; }
if (!ancestry) { ancestry = []; }
switch(selector.type) {
case 'wildcard':
return true;
case 'identifier':
return selector.value.toLowerCase() === node.type.toLowerCase();
case 'field':
path = selector.name.split('.');
ancestor = ancestry[path.length - 1];
return inPath(node, ancestor, path);
case 'matches':
for (i = 0, l = selector.selectors.length; i < l; ++i) {
if (matches(node, selector.selectors[i], ancestry)) { return true; }
}
return false;
case 'compound':
for (i = 0, l = selector.selectors.length; i < l; ++i) {
if (!matches(node, selector.selectors[i], ancestry)) { return false; }
}
return true;
case 'not':
for (i = 0, l = selector.selectors.length; i < l; ++i) {
if (matches(node, selector.selectors[i], ancestry)) { return false; }
}
return true;
case 'has':
var a, collector = [];
for (i = 0, l = selector.selectors.length; i < l; ++i) {
a = [];
estraverse.traverse(node, {
enter: function (node, parent) {
if (parent != null) { a.unshift(parent); }
if (matches(node, selector.selectors[i], a)) {
collector.push(node);
}
},
leave: function () { a.shift(); }
});
}
return collector.length !== 0;
case 'child':
if (matches(node, selector.right, ancestry)) {
return matches(ancestry[0], selector.left, ancestry.slice(1));
}
return false;
case 'descendant':
if (matches(node, selector.right, ancestry)) {
for (i = 0, l = ancestry.length; i < l; ++i) {
if (matches(ancestry[i], selector.left, ancestry.slice(i + 1))) {
return true;
}
}
}
return false;
case 'attribute':
p = getPath(node, selector.name);
switch (selector.operator) {
case null:
case void 0:
return p != null;
case '=':
switch (selector.value.type) {
case 'regexp': return typeof p === 'string' && selector.value.value.test(p);
case 'literal': return '' + selector.value.value === '' + p;
case 'type': return selector.value.value === typeof p;
}
case '!=':
switch (selector.value.type) {
case 'regexp': return !selector.value.value.test(p);
case 'literal': return '' + selector.value.value !== '' + p;
case 'type': return selector.value.value !== typeof p;
}
case '<=': return p <= selector.value.value;
case '<': return p < selector.value.value;
case '>': return p > selector.value.value;
case '>=': return p >= selector.value.value;
}
case 'sibling':
return matches(node, selector.right, ancestry) &&
sibling(node, selector.left, ancestry, LEFT_SIDE) ||
selector.left.subject &&
matches(node, selector.left, ancestry) &&
sibling(node, selector.right, ancestry, RIGHT_SIDE);
case 'adjacent':
return matches(node, selector.right, ancestry) &&
adjacent(node, selector.left, ancestry, LEFT_SIDE) ||
selector.right.subject &&
matches(node, selector.left, ancestry) &&
adjacent(node, selector.right, ancestry, RIGHT_SIDE);
case 'nth-child':
return matches(node, selector.right, ancestry) &&
nthChild(node, ancestry, function (length) {
return selector.index.value - 1;
});
case 'nth-last-child':
return matches(node, selector.right, ancestry) &&
nthChild(node, ancestry, function (length) {
return length - selector.index.value;
});
case 'class':
if(!node.type) return false;
switch(selector.name.toLowerCase()){
case 'statement':
if(node.type.slice(-9) === 'Statement') return true;
// fallthrough: interface Declaration <: Statement { }
case 'declaration':
return node.type.slice(-11) === 'Declaration';
case 'pattern':
if(node.type.slice(-7) === 'Pattern') return true;
// fallthrough: interface Expression <: Node, Pattern { }
case 'expression':
return node.type.slice(-10) === 'Expression' ||
node.type.slice(-7) === 'Literal' ||
(
node.type === 'Identifier' &&
(ancestry.length === 0 || ancestry[0].type !== 'MetaProperty')
) ||
node.type === 'MetaProperty';
case 'function':
return node.type.slice(0, 8) === 'Function' ||
node.type === 'ArrowFunctionExpression';
}
throw new Error('Unknown class name: ' + selector.name);
}
throw new Error('Unknown selector type: ' + selector.type);
}
/*
* Determines if the given node has a sibling that matches the given selector.
*/
function sibling(node, selector, ancestry, side) {
var parent = ancestry[0], listProp, startIndex, keys, i, l, k, lowerBound, upperBound;
if (!parent) { return false; }
keys = estraverse.VisitorKeys[parent.type];
for (i = 0, l = keys.length; i < l; ++i) {
listProp = parent[keys[i]];
if (isArray(listProp)) {
startIndex = listProp.indexOf(node);
if (startIndex < 0) { continue; }
if (side === LEFT_SIDE) {
lowerBound = 0;
upperBound = startIndex;
} else {
lowerBound = startIndex + 1;
upperBound = listProp.length;
}
for (k = lowerBound; k < upperBound; ++k) {
if (matches(listProp[k], selector, ancestry)) {
return true;
}
}
}
}
return false;
}
/*
* Determines if the given node has an asjacent sibling that matches the given selector.
*/
function adjacent(node, selector, ancestry, side) {
var parent = ancestry[0], listProp, keys, i, l, idx;
if (!parent) { return false; }
keys = estraverse.VisitorKeys[parent.type];
for (i = 0, l = keys.length; i < l; ++i) {
listProp = parent[keys[i]];
if (isArray(listProp)) {
idx = listProp.indexOf(node);
if (idx < 0) { continue; }
if (side === LEFT_SIDE && idx > 0 && matches(listProp[idx - 1], selector, ancestry)) {
return true;
}
if (side === RIGHT_SIDE && idx < listProp.length - 1 && matches(listProp[idx + 1], selector, ancestry)) {
return true;
}
}
}
return false;
}
/*
* Determines if the given node is the nth child, determined by idxFn, which is given the containing list's length.
*/
function nthChild(node, ancestry, idxFn) {
var parent = ancestry[0], listProp, keys, i, l, idx;
if (!parent) { return false; }
keys = estraverse.VisitorKeys[parent.type];
for (i = 0, l = keys.length; i < l; ++i) {
listProp = parent[keys[i]];
if (isArray(listProp)) {
idx = listProp.indexOf(node);
if (idx >= 0 && idx === idxFn(listProp.length)) { return true; }
}
}
return false;
}
/*
* For each selector node marked as a subject, find the portion of the selector that the subject must match.
*/
function subjects(selector, ancestor) {
var results, p;
if (selector == null || typeof selector != 'object') { return []; }
if (ancestor == null) { ancestor = selector; }
results = selector.subject ? [ancestor] : [];
for(p in selector) {
if(!{}.hasOwnProperty.call(selector, p)) { continue; }
[].push.apply(results, subjects(selector[p], p === 'left' ? selector[p] : ancestor));
}
return results;
}
/**
* From a JS AST and a selector AST, collect all JS AST nodes that match the selector.
*/
function match(ast, selector) {
var ancestry = [], results = [], altSubjects, i, l, k, m;
if (!selector) { return results; }
altSubjects = subjects(selector);
estraverse.traverse(ast, {
enter: function (node, parent) {
if (parent != null) { ancestry.unshift(parent); }
if (matches(node, selector, ancestry)) {
if (altSubjects.length) {
for (i = 0, l = altSubjects.length; i < l; ++i) {
if (matches(node, altSubjects[i], ancestry)) { results.push(node); }
for (k = 0, m = ancestry.length; k < m; ++k) {
if (matches(ancestry[k], altSubjects[i], ancestry.slice(k + 1))) {
results.push(ancestry[k]);
}
}
}
} else {
results.push(node);
}
}
},
leave: function () { ancestry.shift(); }
});
return results;
}
/**
* Parse a selector string and return its AST.
*/
function parse(selector) {
return parser.parse(selector);
}
/**
* Query the code AST using the selector string.
*/
function query(ast, selector) {
return match(ast, parse(selector));
}
query.parse = parse;
query.match = match;
query.matches = matches;
return query.query = query;
}
if (typeof define === "function" && define.amd) {
define(esqueryModule);
} else if (typeof module !== 'undefined' && module.exports) {
module.exports = esqueryModule();
} else {
this.esquery = esqueryModule();
}
})();