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app_vue/node_modules/eslint/lib/rules/prefer-spread.js

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+/**
+ * @fileoverview A rule to suggest using of the spread operator instead of `.apply()`.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+const astUtils = require("./utils/ast-utils");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Checks whether or not a node is a `.apply()` for variadic.
+ * @param {ASTNode} node A CallExpression node to check.
+ * @returns {boolean} Whether or not the node is a `.apply()` for variadic.
+ */
+function isVariadicApplyCalling(node) {
+    return (
+        astUtils.isSpecificMemberAccess(node.callee, null, "apply") &&
+        node.arguments.length === 2 &&
+        node.arguments[1].type !== "ArrayExpression" &&
+        node.arguments[1].type !== "SpreadElement"
+    );
+}
+
+/**
+ * Checks whether or not `thisArg` is not changed by `.apply()`.
+ * @param {ASTNode|null} expectedThis The node that is the owner of the applied function.
+ * @param {ASTNode} thisArg The node that is given to the first argument of the `.apply()`.
+ * @param {RuleContext} context The ESLint rule context object.
+ * @returns {boolean} Whether or not `thisArg` is not changed by `.apply()`.
+ */
+function isValidThisArg(expectedThis, thisArg, context) {
+    if (!expectedThis) {
+        return astUtils.isNullOrUndefined(thisArg);
+    }
+    return astUtils.equalTokens(expectedThis, thisArg, context);
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        type: "suggestion",
+
+        docs: {
+            description: "require spread operators instead of `.apply()`",
+            category: "ECMAScript 6",
+            recommended: false,
+            url: "https://eslint.org/docs/rules/prefer-spread"
+        },
+
+        schema: [],
+        fixable: null,
+
+        messages: {
+            preferSpread: "Use the spread operator instead of '.apply()'."
+        }
+    },
+
+    create(context) {
+        const sourceCode = context.getSourceCode();
+
+        return {
+            CallExpression(node) {
+                if (!isVariadicApplyCalling(node)) {
+                    return;
+                }
+
+                const applied = astUtils.skipChainExpression(astUtils.skipChainExpression(node.callee).object);
+                const expectedThis = (applied.type === "MemberExpression") ? applied.object : null;
+                const thisArg = node.arguments[0];
+
+                if (isValidThisArg(expectedThis, thisArg, sourceCode)) {
+                    context.report({
+                        node,
+                        messageId: "preferSpread"
+                    });
+                }
+            }
+        };
+    }
+};