| /** |
| * @fileoverview Ensure handling of errors when we know they exist. |
| * @author Jamund Ferguson |
| */ |
| |
| "use strict"; |
| |
| //------------------------------------------------------------------------------ |
| // Rule Definition |
| //------------------------------------------------------------------------------ |
| |
| module.exports = { |
| meta: { |
| type: "suggestion", |
| |
| docs: { |
| description: "require error handling in callbacks", |
| category: "Node.js and CommonJS", |
| recommended: false, |
| url: "https://eslint.org/docs/rules/handle-callback-err" |
| }, |
| |
| schema: [ |
| { |
| type: "string" |
| } |
| ], |
| messages: { |
| expected: "Expected error to be handled." |
| } |
| }, |
| |
| create(context) { |
| |
| const errorArgument = context.options[0] || "err"; |
| |
| /** |
| * Checks if the given argument should be interpreted as a regexp pattern. |
| * @param {string} stringToCheck The string which should be checked. |
| * @returns {boolean} Whether or not the string should be interpreted as a pattern. |
| */ |
| function isPattern(stringToCheck) { |
| const firstChar = stringToCheck[0]; |
| |
| return firstChar === "^"; |
| } |
| |
| /** |
| * Checks if the given name matches the configured error argument. |
| * @param {string} name The name which should be compared. |
| * @returns {boolean} Whether or not the given name matches the configured error variable name. |
| */ |
| function matchesConfiguredErrorName(name) { |
| if (isPattern(errorArgument)) { |
| const regexp = new RegExp(errorArgument, "u"); |
| |
| return regexp.test(name); |
| } |
| return name === errorArgument; |
| } |
| |
| /** |
| * Get the parameters of a given function scope. |
| * @param {Object} scope The function scope. |
| * @returns {Array} All parameters of the given scope. |
| */ |
| function getParameters(scope) { |
| return scope.variables.filter(variable => variable.defs[0] && variable.defs[0].type === "Parameter"); |
| } |
| |
| /** |
| * Check to see if we're handling the error object properly. |
| * @param {ASTNode} node The AST node to check. |
| * @returns {void} |
| */ |
| function checkForError(node) { |
| const scope = context.getScope(), |
| parameters = getParameters(scope), |
| firstParameter = parameters[0]; |
| |
| if (firstParameter && matchesConfiguredErrorName(firstParameter.name)) { |
| if (firstParameter.references.length === 0) { |
| context.report({ node, messageId: "expected" }); |
| } |
| } |
| } |
| |
| return { |
| FunctionDeclaration: checkForError, |
| FunctionExpression: checkForError, |
| ArrowFunctionExpression: checkForError |
| }; |
| |
| } |
| }; |