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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/no-magic-numbers.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/no-magic-numbers.js | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-magic-numbers.js b/tools/node_modules/eslint/lib/rules/no-magic-numbers.js new file mode 100644 index 0000000000..796ecff0f8 --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/no-magic-numbers.js @@ -0,0 +1,149 @@ +/** + * @fileoverview Rule to flag statements that use magic numbers (adapted from https://github.com/danielstjules/buddy.js) + * @author Vincent Lemeunier + */ + +"use strict"; + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "disallow magic numbers", + category: "Best Practices", + recommended: false + }, + + schema: [{ + type: "object", + properties: { + detectObjects: { + type: "boolean" + }, + enforceConst: { + type: "boolean" + }, + ignore: { + type: "array", + items: { + type: "number" + }, + uniqueItems: true + }, + ignoreArrayIndexes: { + type: "boolean" + } + }, + additionalProperties: false + }] + }, + + create(context) { + const config = context.options[0] || {}, + detectObjects = !!config.detectObjects, + enforceConst = !!config.enforceConst, + ignore = config.ignore || [], + ignoreArrayIndexes = !!config.ignoreArrayIndexes; + + /** + * Returns whether the node is number literal + * @param {Node} node - the node literal being evaluated + * @returns {boolean} true if the node is a number literal + */ + function isNumber(node) { + return typeof node.value === "number"; + } + + /** + * Returns whether the number should be ignored + * @param {number} num - the number + * @returns {boolean} true if the number should be ignored + */ + function shouldIgnoreNumber(num) { + return ignore.indexOf(num) !== -1; + } + + /** + * Returns whether the number should be ignored when used as a radix within parseInt() or Number.parseInt() + * @param {ASTNode} parent - the non-"UnaryExpression" parent + * @param {ASTNode} node - the node literal being evaluated + * @returns {boolean} true if the number should be ignored + */ + function shouldIgnoreParseInt(parent, node) { + return parent.type === "CallExpression" && node === parent.arguments[1] && + (parent.callee.name === "parseInt" || + parent.callee.type === "MemberExpression" && + parent.callee.object.name === "Number" && + parent.callee.property.name === "parseInt"); + } + + /** + * Returns whether the number should be ignored when used to define a JSX prop + * @param {ASTNode} parent - the non-"UnaryExpression" parent + * @returns {boolean} true if the number should be ignored + */ + function shouldIgnoreJSXNumbers(parent) { + return parent.type.indexOf("JSX") === 0; + } + + /** + * Returns whether the number should be ignored when used as an array index with enabled 'ignoreArrayIndexes' option. + * @param {ASTNode} parent - the non-"UnaryExpression" parent. + * @returns {boolean} true if the number should be ignored + */ + function shouldIgnoreArrayIndexes(parent) { + return parent.type === "MemberExpression" && ignoreArrayIndexes; + } + + return { + Literal(node) { + let parent = node.parent, + value = node.value, + raw = node.raw; + const okTypes = detectObjects ? [] : ["ObjectExpression", "Property", "AssignmentExpression"]; + + if (!isNumber(node)) { + return; + } + + // For negative magic numbers: update the value and parent node + if (parent.type === "UnaryExpression" && parent.operator === "-") { + node = parent; + parent = node.parent; + value = -value; + raw = `-${raw}`; + } + + if (shouldIgnoreNumber(value) || + shouldIgnoreParseInt(parent, node) || + shouldIgnoreArrayIndexes(parent) || + shouldIgnoreJSXNumbers(parent)) { + return; + } + + if (parent.type === "VariableDeclarator") { + if (enforceConst && parent.parent.kind !== "const") { + context.report({ + node, + message: "Number constants declarations must use 'const'." + }); + } + } else if ( + okTypes.indexOf(parent.type) === -1 || + (parent.type === "AssignmentExpression" && parent.left.type === "Identifier") + ) { + context.report({ + node, + message: "No magic number: {{raw}}.", + data: { + raw + } + }); + } + } + }; + } +}; |