1 files changed, 177 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/getter-return.js b/tools/node_modules/eslint/lib/rules/getter-return.js
new file mode 100644
index 0000000000..6eb1efc00c
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/getter-return.js
@@ -0,0 +1,177 @@
+/**
+ * @fileoverview Enforces that a return statement is present in property getters.
+ * @author Aladdin-ADD(hh_2013@foxmail.com)
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+const TARGET_NODE_TYPE = /^(?:Arrow)?FunctionExpression$/;
+
+/**
+ * Checks a given code path segment is reachable.
+ *
+ * @param {CodePathSegment} segment - A segment to check.
+ * @returns {boolean} `true` if the segment is reachable.
+ */
+function isReachable(segment) {
+    return segment.reachable;
+}
+
+/**
+ * Gets a readable location.
+ *
+ * - FunctionExpression -> the function name or `function` keyword.
+ *
+ * @param {ASTNode} node - A function node to get.
+ * @returns {ASTNode|Token} The node or the token of a location.
+ */
+function getId(node) {
+    return node.id || node;
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce `return` statements in getters",
+            category: "Possible Errors",
+            recommended: false
+        },
+        fixable: null,
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    allowImplicit: {
+                        type: "boolean"
+                    }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+
+        const options = context.options[0] || { allowImplicit: false };
+
+        let funcInfo = {
+            upper: null,
+            codePath: null,
+            hasReturn: false,
+            shouldCheck: false,
+            node: null
+        };
+
+        /**
+         * Checks whether or not the last code path segment is reachable.
+         * Then reports this function if the segment is reachable.
+         *
+         * If the last code path segment is reachable, there are paths which are not
+         * returned or thrown.
+         *
+         * @param {ASTNode} node - A node to check.
+         * @returns {void}
+         */
+        function checkLastSegment(node) {
+            if (funcInfo.shouldCheck &&
+                funcInfo.codePath.currentSegments.some(isReachable)
+            ) {
+                context.report({
+                    node,
+                    loc: getId(node).loc.start,
+                    message: funcInfo.hasReturn
+                        ? "Expected {{name}} to always return a value."
+                        : "Expected to return a value in {{name}}.",
+                    data: {
+                        name: astUtils.getFunctionNameWithKind(funcInfo.node)
+                    }
+                });
+            }
+        }
+
+        /**
+         * Checks whether a node means a getter function.
+         * @param {ASTNode} node - a node to check.
+         * @returns {boolean} if node means a getter, return true; else return false.
+         */
+        function isGetter(node) {
+            const parent = node.parent;
+
+            if (TARGET_NODE_TYPE.test(node.type) && node.body.type === "BlockStatement") {
+                if (parent.kind === "get") {
+                    return true;
+                }
+                if (parent.type === "Property" && astUtils.getStaticPropertyName(parent) === "get" && parent.parent.type === "ObjectExpression") {
+
+                    // Object.defineProperty()
+                    if (parent.parent.parent.type === "CallExpression" &&
+                        astUtils.getStaticPropertyName(parent.parent.parent.callee) === "defineProperty") {
+                        return true;
+                    }
+
+                    // Object.defineProperties()
+                    if (parent.parent.parent.type === "Property" &&
+                        parent.parent.parent.parent.type === "ObjectExpression" &&
+                        parent.parent.parent.parent.parent.type === "CallExpression" &&
+                        astUtils.getStaticPropertyName(parent.parent.parent.parent.parent.callee) === "defineProperties") {
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+        return {
+
+            // Stacks this function's information.
+            onCodePathStart(codePath, node) {
+                funcInfo = {
+                    upper: funcInfo,
+                    codePath,
+                    hasReturn: false,
+                    shouldCheck: isGetter(node),
+                    node
+                };
+            },
+
+            // Pops this function's information.
+            onCodePathEnd() {
+                funcInfo = funcInfo.upper;
+            },
+
+            // Checks the return statement is valid.
+            ReturnStatement(node) {
+                if (funcInfo.shouldCheck) {
+                    funcInfo.hasReturn = true;
+
+                    // if allowImplicit: false, should also check node.argument
+                    if (!options.allowImplicit && !node.argument) {
+                        context.report({
+                            node,
+                            message: "Expected to return a value in {{name}}.",
+                            data: {
+                                name: astUtils.getFunctionNameWithKind(funcInfo.node)
+                            }
+                        });
+                    }
+                }
+            },
+
+            // Reports a given function if the last path is reachable.
+            "FunctionExpression:exit": checkLastSegment,
+            "ArrowFunctionExpression:exit": checkLastSegment
+        };
+    }
+};