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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/block-scoped-var.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/block-scoped-var.js | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/block-scoped-var.js b/tools/node_modules/eslint/lib/rules/block-scoped-var.js new file mode 100644 index 0000000000..0b4d855fae --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/block-scoped-var.js @@ -0,0 +1,115 @@ +/** + * @fileoverview Rule to check for "block scoped" variables by binding context + * @author Matt DuVall <http://www.mattduvall.com> + */ +"use strict"; + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "enforce the use of variables within the scope they are defined", + category: "Best Practices", + recommended: false + }, + + schema: [] + }, + + create(context) { + let stack = []; + + /** + * Makes a block scope. + * @param {ASTNode} node - A node of a scope. + * @returns {void} + */ + function enterScope(node) { + stack.push(node.range); + } + + /** + * Pops the last block scope. + * @returns {void} + */ + function exitScope() { + stack.pop(); + } + + /** + * Reports a given reference. + * @param {eslint-scope.Reference} reference - A reference to report. + * @returns {void} + */ + function report(reference) { + const identifier = reference.identifier; + + context.report({ node: identifier, message: "'{{name}}' used outside of binding context.", data: { name: identifier.name } }); + } + + /** + * Finds and reports references which are outside of valid scopes. + * @param {ASTNode} node - A node to get variables. + * @returns {void} + */ + function checkForVariables(node) { + if (node.kind !== "var") { + return; + } + + // Defines a predicate to check whether or not a given reference is outside of valid scope. + const scopeRange = stack[stack.length - 1]; + + /** + * Check if a reference is out of scope + * @param {ASTNode} reference node to examine + * @returns {boolean} True is its outside the scope + * @private + */ + function isOutsideOfScope(reference) { + const idRange = reference.identifier.range; + + return idRange[0] < scopeRange[0] || idRange[1] > scopeRange[1]; + } + + // Gets declared variables, and checks its references. + const variables = context.getDeclaredVariables(node); + + for (let i = 0; i < variables.length; ++i) { + + // Reports. + variables[i] + .references + .filter(isOutsideOfScope) + .forEach(report); + } + } + + return { + Program(node) { + stack = [node.range]; + }, + + // Manages scopes. + BlockStatement: enterScope, + "BlockStatement:exit": exitScope, + ForStatement: enterScope, + "ForStatement:exit": exitScope, + ForInStatement: enterScope, + "ForInStatement:exit": exitScope, + ForOfStatement: enterScope, + "ForOfStatement:exit": exitScope, + SwitchStatement: enterScope, + "SwitchStatement:exit": exitScope, + CatchClause: enterScope, + "CatchClause:exit": exitScope, + + // Finds and reports references which are outside of valid scope. + VariableDeclaration: checkForVariables + }; + + } +}; |