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home/ags/node_modules/eslint-plugin-n/lib/rules/no-path-concat.js

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+/**
+ * @author Nicholas C. Zakas
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+
+const path = require("path")
+const {
+    READ,
+    ReferenceTracker,
+    getStringIfConstant,
+} = require("@eslint-community/eslint-utils")
+
+/**
+ * Get the first char of the specified template element.
+ * @param {TemplateLiteral} node The `TemplateLiteral` node to get.
+ * @param {number} i The number of template elements to get first char.
+ * @param {Set<Node>} sepNodes The nodes of `path.sep`.
+ * @param {import("escope").Scope} globalScope The global scope object.
+ * @param {string[]} outNextChars The array to collect chars.
+ * @returns {void}
+ */
+function collectFirstCharsOfTemplateElement(
+    node,
+    i,
+    sepNodes,
+    globalScope,
+    outNextChars
+) {
+    const element = node.quasis[i].value.cooked
+
+    if (element == null) {
+        return
+    }
+    if (element !== "") {
+        outNextChars.push(element[0])
+        return
+    }
+    if (node.expressions.length > i) {
+        collectFirstChars(
+            node.expressions[i],
+            sepNodes,
+            globalScope,
+            outNextChars
+        )
+    }
+}
+
+/**
+ * Get the first char of a given node.
+ * @param {TemplateLiteral} node The `TemplateLiteral` node to get.
+ * @param {Set<Node>} sepNodes The nodes of `path.sep`.
+ * @param {import("escope").Scope} globalScope The global scope object.
+ * @param {string[]} outNextChars The array to collect chars.
+ * @returns {void}
+ */
+function collectFirstChars(node, sepNodes, globalScope, outNextChars) {
+    switch (node.type) {
+        case "AssignmentExpression":
+            collectFirstChars(node.right, sepNodes, globalScope, outNextChars)
+            break
+        case "BinaryExpression":
+            collectFirstChars(node.left, sepNodes, globalScope, outNextChars)
+            break
+        case "ConditionalExpression":
+            collectFirstChars(
+                node.consequent,
+                sepNodes,
+                globalScope,
+                outNextChars
+            )
+            collectFirstChars(
+                node.alternate,
+                sepNodes,
+                globalScope,
+                outNextChars
+            )
+            break
+        case "LogicalExpression":
+            collectFirstChars(node.left, sepNodes, globalScope, outNextChars)
+            collectFirstChars(node.right, sepNodes, globalScope, outNextChars)
+            break
+        case "SequenceExpression":
+            collectFirstChars(
+                node.expressions[node.expressions.length - 1],
+                sepNodes,
+                globalScope,
+                outNextChars
+            )
+            break
+        case "TemplateLiteral":
+            collectFirstCharsOfTemplateElement(
+                node,
+                0,
+                sepNodes,
+                globalScope,
+                outNextChars
+            )
+            break
+
+        case "Identifier":
+        case "MemberExpression":
+            if (sepNodes.has(node)) {
+                outNextChars.push(path.sep)
+                break
+            }
+        // fallthrough
+        default: {
+            const str = getStringIfConstant(node, globalScope)
+            if (str) {
+                outNextChars.push(str[0])
+            }
+        }
+    }
+}
+
+/**
+ * Check if a char is a path separator or not.
+ * @param {string} c The char to check.
+ * @returns {boolean} `true` if the char is a path separator.
+ */
+function isPathSeparator(c) {
+    return c === "/" || c === path.sep
+}
+
+/**
+ * Check if the given Identifier node is followed by string concatenation with a
+ * path separator.
+ * @param {Identifier} node The `__dirname` or `__filename` node to check.
+ * @param {Set<Node>} sepNodes The nodes of `path.sep`.
+ * @param {import("escope").Scope} globalScope The global scope object.
+ * @returns {boolean} `true` if the given Identifier node is followed by string
+ * concatenation with a path separator.
+ */
+function isConcat(node, sepNodes, globalScope) {
+    const parent = node.parent
+    const nextChars = []
+
+    if (
+        parent.type === "BinaryExpression" &&
+        parent.operator === "+" &&
+        parent.left === node
+    ) {
+        collectFirstChars(
+            parent.right,
+            sepNodes,
+            globalScope,
+            /* out */ nextChars
+        )
+    } else if (parent.type === "TemplateLiteral") {
+        collectFirstCharsOfTemplateElement(
+            parent,
+            parent.expressions.indexOf(node) + 1,
+            sepNodes,
+            globalScope,
+            /* out */ nextChars
+        )
+    }
+
+    return nextChars.some(isPathSeparator)
+}
+
+module.exports = {
+    meta: {
+        type: "suggestion",
+        docs: {
+            description:
+                "disallow string concatenation with `__dirname` and `__filename`",
+            recommended: false,
+            url: "https://github.com/eslint-community/eslint-plugin-n/blob/HEAD/docs/rules/no-path-concat.md",
+        },
+        fixable: null,
+        schema: [],
+        messages: {
+            usePathFunctions:
+                "Use path.join() or path.resolve() instead of string concatenation.",
+        },
+    },
+
+    create(context) {
+        return {
+            "Program:exit"(node) {
+                const sourceCode = context.sourceCode ?? context.getSourceCode() // TODO: just use context.sourceCode when dropping eslint < v9
+                const globalScope =
+                    sourceCode.getScope?.(node) ?? context.getScope()
+                const tracker = new ReferenceTracker(globalScope)
+                const sepNodes = new Set()
+
+                // Collect `paht.sep` references
+                for (const { node } of tracker.iterateCjsReferences({
+                    path: { sep: { [READ]: true } },
+                })) {
+                    sepNodes.add(node)
+                }
+                for (const { node } of tracker.iterateEsmReferences({
+                    path: { sep: { [READ]: true } },
+                })) {
+                    sepNodes.add(node)
+                }
+
+                // Verify `__dirname` and `__filename`
+                for (const { node } of tracker.iterateGlobalReferences({
+                    __dirname: { [READ]: true },
+                    __filename: { [READ]: true },
+                })) {
+                    if (isConcat(node, sepNodes, globalScope)) {
+                        context.report({
+                            node: node.parent,
+                            messageId: "usePathFunctions",
+                        })
+                    }
+                }
+            },
+        }
+    },
+}