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Merge pull request #30 from RoboPhred/fix-func-decl-invoke
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Fix function bodies being invoked during function declaration.
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@goto-bus-stop
goto-bus-stop committed Mar 7, 2020
2 parents 9d39dd5 + 23bc6ca commit aa0eaeb
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Showing 2 changed files with 55 additions and 22 deletions.
47 changes: 26 additions & 21 deletions index.js
View file
Expand Up @@ -4,12 +4,12 @@ module.exports = function (ast, vars) {
if (!vars) vars = {};
var FAIL = {};

var result = (function walk (node, scopeVars) {
var result = (function walk (node, noExecute) {
if (node.type === 'Literal') {
return node.value;
}
else if (node.type === 'UnaryExpression'){
var val = walk(node.argument)
var val = walk(node.argument, noExecute)
if (node.operator === '+') return +val
if (node.operator === '-') return -val
if (node.operator === '~') return ~val
Expand All @@ -19,7 +19,7 @@ module.exports = function (ast, vars) {
else if (node.type === 'ArrayExpression') {
var xs = [];
for (var i = 0, l = node.elements.length; i < l; i++) {
var x = walk(node.elements[i]);
var x = walk(node.elements[i], noExecute);
if (x === FAIL) return FAIL;
xs.push(x);
}
Expand All @@ -31,7 +31,7 @@ module.exports = function (ast, vars) {
var prop = node.properties[i];
var value = prop.value === null
? prop.value
: walk(prop.value)
: walk(prop.value, noExecute)
;
if (value === FAIL) return FAIL;
obj[prop.key.value || prop.key.name] = value;
Expand Down Expand Up @@ -59,9 +59,9 @@ module.exports = function (ast, vars) {
return r;
}

var l = walk(node.left);
var l = walk(node.left, noExecute);
if (l === FAIL) return FAIL;
var r = walk(node.right);
var r = walk(node.right, noExecute);
if (r === FAIL) return FAIL;

if (op === '==') return l == r;
Expand Down Expand Up @@ -96,23 +96,29 @@ module.exports = function (ast, vars) {
else return FAIL;
}
else if (node.type === 'CallExpression') {
var callee = walk(node.callee);
var callee = walk(node.callee, noExecute);
if (callee === FAIL) return FAIL;
if (typeof callee !== 'function') return FAIL;


var ctx = node.callee.object ? walk(node.callee.object) : FAIL;
var ctx = node.callee.object ? walk(node.callee.object, noExecute) : FAIL;
if (ctx === FAIL) ctx = null;

var args = [];
for (var i = 0, l = node.arguments.length; i < l; i++) {
var x = walk(node.arguments[i]);
var x = walk(node.arguments[i], noExecute);
if (x === FAIL) return FAIL;
args.push(x);
}

if (noExecute) {
return undefined;
}

return callee.apply(ctx, args);
}
else if (node.type === 'MemberExpression') {
var obj = walk(node.object);
var obj = walk(node.object, noExecute);
// do not allow access to methods on Function
if((obj === FAIL) || (typeof obj == 'function')){
return FAIL;
Expand All @@ -121,26 +127,25 @@ module.exports = function (ast, vars) {
if (isUnsafeProperty(node.property.name)) return FAIL;
return obj[node.property.name];
}
var prop = walk(node.property);
var prop = walk(node.property, noExecute);
if (prop === null || prop === FAIL) return FAIL;
if (isUnsafeProperty(prop)) return FAIL;
return obj[prop];
}
else if (node.type === 'ConditionalExpression') {
var val = walk(node.test)
var val = walk(node.test, noExecute)
if (val === FAIL) return FAIL;
return val ? walk(node.consequent) : walk(node.alternate)
return val ? walk(node.consequent) : walk(node.alternate, noExecute)
}
else if (node.type === 'ExpressionStatement') {
var val = walk(node.expression)
var val = walk(node.expression, noExecute)
if (val === FAIL) return FAIL;
return val;
}
else if (node.type === 'ReturnStatement') {
return walk(node.argument)
return walk(node.argument, noExecute)
}
else if (node.type === 'FunctionExpression') {

var bodies = node.body.body;

// Create a "scope" for our arguments
Expand All @@ -157,7 +162,7 @@ module.exports = function (ast, vars) {
else return FAIL;
}
for(var i in bodies){
if(walk(bodies[i]) === FAIL){
if(walk(bodies[i], true) === FAIL){
return FAIL;
}
}
Expand All @@ -173,14 +178,14 @@ module.exports = function (ast, vars) {
else if (node.type === 'TemplateLiteral') {
var str = '';
for (var i = 0; i < node.expressions.length; i++) {
str += walk(node.quasis[i]);
str += walk(node.expressions[i]);
str += walk(node.quasis[i], noExecute);
str += walk(node.expressions[i], noExecute);
}
str += walk(node.quasis[i]);
str += walk(node.quasis[i], noExecute);
return str;
}
else if (node.type === 'TaggedTemplateExpression') {
var tag = walk(node.tag);
var tag = walk(node.tag, noExecute);
var quasi = node.quasi;
var strings = quasi.quasis.map(walk);
var values = quasi.expressions.map(walk);
Expand Down
30 changes: 29 additions & 1 deletion test/eval.js
View file
Expand Up @@ -44,6 +44,20 @@ test('array methods', function(t) {
t.deepEqual(evaluate(ast), [2, 4, 6]);
});

test('array methods invocation count', function(t) {
t.plan(2);

var variables = {
values: [1, 2, 3],
receiver: []
};
var src = 'values.forEach(function(x) { receiver.push(x); })'
var ast = parse(src).body[0].expression;
evaluate(ast, variables);
t.equal(variables.receiver.length, 3);
t.deepEqual(variables.receiver, [1, 2, 3]);
})

test('array methods with vars', function(t) {
t.plan(1);

Expand Down Expand Up @@ -146,4 +160,18 @@ test('short circuit evaluation OR', function(t) {
var ast = parse(src).body[0].expression;
evaluate(ast, variables);
t.equals(fnInvoked, false);
})
})

test('function declaration does not invoke CallExpressions', function(t) {
t.plan(1);

var invoked = false;
var variables = {
noop: function(){},
onInvoke: function() {invoked = true}
};
var src = 'noop(function(){ onInvoke(); })';
var ast = parse(src).body[0].expression;
evaluate(ast, variables);
t.equal(invoked, false);
});

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