--- /dev/null
+/**
+ * @fileoverview A rule to set the maximum number of line of code in a function.
+ * @author Pete Ward <peteward44@gmail.com>
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("./utils/ast-utils");
+
+const lodash = require("lodash");
+
+//------------------------------------------------------------------------------
+// Constants
+//------------------------------------------------------------------------------
+
+const OPTIONS_SCHEMA = {
+ type: "object",
+ properties: {
+ max: {
+ type: "integer",
+ minimum: 0
+ },
+ skipComments: {
+ type: "boolean"
+ },
+ skipBlankLines: {
+ type: "boolean"
+ },
+ IIFEs: {
+ type: "boolean"
+ }
+ },
+ additionalProperties: false
+};
+
+const OPTIONS_OR_INTEGER_SCHEMA = {
+ oneOf: [
+ OPTIONS_SCHEMA,
+ {
+ type: "integer",
+ minimum: 1
+ }
+ ]
+};
+
+/**
+ * Given a list of comment nodes, return a map with numeric keys (source code line numbers) and comment token values.
+ * @param {Array} comments An array of comment nodes.
+ * @returns {Map.<string,Node>} A map with numeric keys (source code line numbers) and comment token values.
+ */
+function getCommentLineNumbers(comments) {
+ const map = new Map();
+
+ if (!comments) {
+ return map;
+ }
+ comments.forEach(comment => {
+ for (let i = comment.loc.start.line; i <= comment.loc.end.line; i++) {
+ map.set(i, comment);
+ }
+ });
+ return map;
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "enforce a maximum number of line of code in a function",
+ category: "Stylistic Issues",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/max-lines-per-function"
+ },
+
+ schema: [
+ OPTIONS_OR_INTEGER_SCHEMA
+ ],
+ messages: {
+ exceed: "{{name}} has too many lines ({{lineCount}}). Maximum allowed is {{maxLines}}."
+ }
+ },
+
+ create(context) {
+ const sourceCode = context.getSourceCode();
+ const lines = sourceCode.lines;
+
+ const option = context.options[0];
+ let maxLines = 50;
+ let skipComments = false;
+ let skipBlankLines = false;
+ let IIFEs = false;
+
+ if (typeof option === "object") {
+ maxLines = typeof option.max === "number" ? option.max : 50;
+ skipComments = !!option.skipComments;
+ skipBlankLines = !!option.skipBlankLines;
+ IIFEs = !!option.IIFEs;
+ } else if (typeof option === "number") {
+ maxLines = option;
+ }
+
+ const commentLineNumbers = getCommentLineNumbers(sourceCode.getAllComments());
+
+ //--------------------------------------------------------------------------
+ // Helpers
+ //--------------------------------------------------------------------------
+
+ /**
+ * Tells if a comment encompasses the entire line.
+ * @param {string} line The source line with a trailing comment
+ * @param {number} lineNumber The one-indexed line number this is on
+ * @param {ASTNode} comment The comment to remove
+ * @returns {boolean} If the comment covers the entire line
+ */
+ function isFullLineComment(line, lineNumber, comment) {
+ const start = comment.loc.start,
+ end = comment.loc.end,
+ isFirstTokenOnLine = start.line === lineNumber && !line.slice(0, start.column).trim(),
+ isLastTokenOnLine = end.line === lineNumber && !line.slice(end.column).trim();
+
+ return comment &&
+ (start.line < lineNumber || isFirstTokenOnLine) &&
+ (end.line > lineNumber || isLastTokenOnLine);
+ }
+
+ /**
+ * Identifies is a node is a FunctionExpression which is part of an IIFE
+ * @param {ASTNode} node Node to test
+ * @returns {boolean} True if it's an IIFE
+ */
+ function isIIFE(node) {
+ return node.type === "FunctionExpression" && node.parent && node.parent.type === "CallExpression" && node.parent.callee === node;
+ }
+
+ /**
+ * Identifies is a node is a FunctionExpression which is embedded within a MethodDefinition or Property
+ * @param {ASTNode} node Node to test
+ * @returns {boolean} True if it's a FunctionExpression embedded within a MethodDefinition or Property
+ */
+ function isEmbedded(node) {
+ if (!node.parent) {
+ return false;
+ }
+ if (node !== node.parent.value) {
+ return false;
+ }
+ if (node.parent.type === "MethodDefinition") {
+ return true;
+ }
+ if (node.parent.type === "Property") {
+ return node.parent.method === true || node.parent.kind === "get" || node.parent.kind === "set";
+ }
+ return false;
+ }
+
+ /**
+ * Count the lines in the function
+ * @param {ASTNode} funcNode Function AST node
+ * @returns {void}
+ * @private
+ */
+ function processFunction(funcNode) {
+ const node = isEmbedded(funcNode) ? funcNode.parent : funcNode;
+
+ if (!IIFEs && isIIFE(node)) {
+ return;
+ }
+ let lineCount = 0;
+
+ for (let i = node.loc.start.line - 1; i < node.loc.end.line; ++i) {
+ const line = lines[i];
+
+ if (skipComments) {
+ if (commentLineNumbers.has(i + 1) && isFullLineComment(line, i + 1, commentLineNumbers.get(i + 1))) {
+ continue;
+ }
+ }
+
+ if (skipBlankLines) {
+ if (line.match(/^\s*$/u)) {
+ continue;
+ }
+ }
+
+ lineCount++;
+ }
+
+ if (lineCount > maxLines) {
+ const name = lodash.upperFirst(astUtils.getFunctionNameWithKind(funcNode));
+
+ context.report({
+ node,
+ messageId: "exceed",
+ data: { name, lineCount, maxLines }
+ });
+ }
+ }
+
+ //--------------------------------------------------------------------------
+ // Public API
+ //--------------------------------------------------------------------------
+
+ return {
+ FunctionDeclaration: processFunction,
+ FunctionExpression: processFunction,
+ ArrowFunctionExpression: processFunction
+ };
+ }
+};
projects / dotfiles / .git / blobdiff