--- /dev/null
+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2017 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Psy\CodeCleaner;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\ClassConstFetch;
+use PhpParser\Node\Expr\ConstFetch;
+use Psy\Exception\FatalErrorException;
+
+/**
+ * Validate that namespaced constant references will succeed.
+ *
+ * This pass throws a FatalErrorException rather than letting PHP run
+ * headfirst into a real fatal error and die.
+ *
+ * @todo Detect constants defined in the current code snippet?
+ * ... Might not be worth it, since it would need to both be defining and
+ * referencing a namespaced constant, which doesn't seem like that big of
+ * a target for failure
+ */
+class ValidConstantPass extends NamespaceAwarePass
+{
+ /**
+ * Validate that namespaced constant references will succeed.
+ *
+ * Note that this does not (yet) detect constants defined in the current code
+ * snippet. It won't happen very often, so we'll punt for now.
+ *
+ * @throws FatalErrorException if a constant reference is not defined
+ *
+ * @param Node $node
+ */
+ public function leaveNode(Node $node)
+ {
+ if ($node instanceof ConstFetch && count($node->name->parts) > 1) {
+ $name = $this->getFullyQualifiedName($node->name);
+ if (!defined($name)) {
+ throw new FatalErrorException(sprintf('Undefined constant %s', $name), 0, 1, null, $node->getLine());
+ }
+ } elseif ($node instanceof ClassConstFetch) {
+ $this->validateClassConstFetchExpression($node);
+ }
+ }
+
+ /**
+ * Validate a class constant fetch expression.
+ *
+ * @throws FatalErrorException if a class constant is not defined
+ *
+ * @param ClassConstFetch $stmt
+ */
+ protected function validateClassConstFetchExpression(ClassConstFetch $stmt)
+ {
+ // give the `class` pseudo-constant a pass
+ if ($stmt->name === 'class') {
+ return;
+ }
+
+ // if class name is an expression, give it a pass for now
+ if (!$stmt->class instanceof Expr) {
+ $className = $this->getFullyQualifiedName($stmt->class);
+
+ // if the class doesn't exist, don't throw an exception… it might be
+ // defined in the same line it's used or something stupid like that.
+ if (class_exists($className) || interface_exists($className)) {
+ $constName = sprintf('%s::%s', $className, $stmt->name);
+ if (!defined($constName)) {
+ $constType = class_exists($className) ? 'Class' : 'Interface';
+ $msg = sprintf('%s constant \'%s\' not found', $constType, $constName);
+ throw new FatalErrorException($msg, 0, 1, null, $stmt->getLine());
+ }
+ }
+ }
+ }
+}