1 files changed, 89 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/func-style.js b/tools/node_modules/eslint/lib/rules/func-style.js
new file mode 100644
index 0000000000..123eae3d8a
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/func-style.js
@@ -0,0 +1,89 @@
+/**
+ * @fileoverview Rule to enforce a particular function style
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce the consistent use of either `function` declarations or expressions",
+            category: "Stylistic Issues",
+            recommended: false
+        },
+
+        schema: [
+            {
+                enum: ["declaration", "expression"]
+            },
+            {
+                type: "object",
+                properties: {
+                    allowArrowFunctions: {
+                        type: "boolean"
+                    }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+
+        const style = context.options[0],
+            allowArrowFunctions = context.options[1] && context.options[1].allowArrowFunctions === true,
+            enforceDeclarations = (style === "declaration"),
+            stack = [];
+
+        const nodesToCheck = {
+            FunctionDeclaration(node) {
+                stack.push(false);
+
+                if (!enforceDeclarations && node.parent.type !== "ExportDefaultDeclaration") {
+                    context.report({ node, message: "Expected a function expression." });
+                }
+            },
+            "FunctionDeclaration:exit"() {
+                stack.pop();
+            },
+
+            FunctionExpression(node) {
+                stack.push(false);
+
+                if (enforceDeclarations && node.parent.type === "VariableDeclarator") {
+                    context.report({ node: node.parent, message: "Expected a function declaration." });
+                }
+            },
+            "FunctionExpression:exit"() {
+                stack.pop();
+            },
+
+            ThisExpression() {
+                if (stack.length > 0) {
+                    stack[stack.length - 1] = true;
+                }
+            }
+        };
+
+        if (!allowArrowFunctions) {
+            nodesToCheck.ArrowFunctionExpression = function() {
+                stack.push(false);
+            };
+
+            nodesToCheck["ArrowFunctionExpression:exit"] = function(node) {
+                const hasThisExpr = stack.pop();
+
+                if (enforceDeclarations && !hasThisExpr && node.parent.type === "VariableDeclarator") {
+                    context.report({ node: node.parent, message: "Expected a function declaration." });
+                }
+            };
+        }
+
+        return nodesToCheck;
+
+    }
+};