tools: replace closure-linter with eslint

PR-URL: https://github.com/iojs/io.js/pull/1539
Fixes: https://github.com/iojs/io.js/issues/1253
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/tools/eslint/lib/rules/no-func-assign.js b/tools/eslint/lib/rules/no-func-assign.js
new file mode 100644
index 0000000000..a9f2858126
--- /dev/null
+++ b/tools/eslint/lib/rules/no-func-assign.js
@@ -0,0 +1,81 @@
+/**
+ * @fileoverview Rule to flag use of function declaration identifiers as variables.
+ * @author Ian Christian Myers
+ * @copyright 2013 Ian Christian Myers. All rights reserved.
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+    //--------------------------------------------------------------------------
+    // Helpers
+    //--------------------------------------------------------------------------
+
+    /*
+     * Walk the scope chain looking for either a FunctionDeclaration or a
+     * VariableDeclaration with the same name as left-hand side of the
+     * AssignmentExpression. If we find the FunctionDeclaration first, then we
+     * warn, because a FunctionDeclaration is trying to become a Variable or a
+     * FunctionExpression. If we find a VariableDeclaration first, then we have
+     * a legitimate shadow variable.
+     */
+    function checkIfIdentifierIsFunction(scope, name) {
+        var variable,
+            def,
+            i,
+            j;
+
+        // Loop over all of the identifiers available in scope.
+        for (i = 0; i < scope.variables.length; i++) {
+            variable = scope.variables[i];
+
+            // For each identifier, see if it was defined in _this_ scope.
+            for (j = 0; j < variable.defs.length; j++) {
+                def = variable.defs[j];
+
+                // Identifier is a function and was declared in this scope
+                if (def.type === "FunctionName" && def.name.name === name) {
+                    return true;
+                }
+
+                // Identifier is a variable and was declared in this scope. This
+                // is a legitimate shadow variable.
+                if (def.name && def.name.name === name) {
+                    return false;
+                }
+            }
+        }
+
+        // Check the upper scope.
+        if (scope.upper) {
+            return checkIfIdentifierIsFunction(scope.upper, name);
+        }
+
+        // We've reached the global scope and haven't found anything.
+        return false;
+    }
+
+    //--------------------------------------------------------------------------
+    // Public API
+    //--------------------------------------------------------------------------
+
+    return {
+
+        "AssignmentExpression": function(node) {
+            var scope = context.getScope(),
+                name = node.left.name;
+
+            if (checkIfIdentifierIsFunction(scope, name)) {
+                context.report(node, "'{{name}}' is a function.", { name: name });
+            }
+
+        }
+
+    };
+
+};