/**
* require `$on` and `$watch` deregistration callbacks to be saved in a variable
*
* Watch and On methods on the scope object should be assigned to a variable, in order to be deleted in a $destroy event handler
* @version 0.1.0
* @category bestPractice
*/
'use strict';
module.exports = function(context) {
function report(node, method) {
context.report(node, 'The "{{method}}" call should be assigned to a variable, in order to be destroyed during the $destroy event', {
method: method
});
}
/**
* Return true if the given node is a call expression calling a function
* named '$on' or '$watch' on an object named '$scope', '$rootScope' or
* 'scope'.
*/
function isScopeOnOrWatch(node, scopes) {
if (node.type !== 'CallExpression') {
return false;
}
var calledFunction = node.callee;
if (calledFunction.type !== 'MemberExpression') {
return false;
}
// can only easily tell what name was used if a simple
// identifiers were used to access it.
var parentObject = calledFunction.object;
var accessedFunction = calledFunction.property;
// cannot check name of the parent object if it is returned from a
// complex expression.
if (parentObject.type !== 'Identifier' ||
accessedFunction.type !== 'Identifier') {
return false;
}
var objectName = parentObject.name;
var functionName = accessedFunction.name;
return scopes.indexOf(objectName) >= 0 && (functionName === '$on' ||
functionName === '$watch');
}
/**
* Return true if the given node is a call expression that has a first
* argument of the string '$destroy'.
*/
function isFirstArgDestroy(node) {
var args = node.arguments;
return (args.length >= 1 &&
args[0].type === 'Literal' &&
args[0].value === '$destroy');
}
return {
CallExpression: function(node) {
if (isScopeOnOrWatch(node, ['$rootScope']) && !isFirstArgDestroy(node)) {
if (node.parent.type !== 'VariableDeclarator' &&
node.parent.type !== 'AssignmentExpression' &&
!(isScopeOnOrWatch(node.parent, ['$rootScope', '$scope', 'scope']) &&
isFirstArgDestroy(node.parent))) {
report(node, node.callee.property.name);
}
}
}
};
};
module.exports.schema = [
// JSON Schema for rule options goes here
];
|