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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/init-declarations.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/init-declarations.js | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/init-declarations.js b/tools/node_modules/eslint/lib/rules/init-declarations.js new file mode 100644 index 0000000000..1f53f3dfc4 --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/init-declarations.js @@ -0,0 +1,137 @@ +/** + * @fileoverview A rule to control the style of variable initializations. + * @author Colin Ihrig + */ + +"use strict"; + +//------------------------------------------------------------------------------ +// Helpers +//------------------------------------------------------------------------------ + +/** + * Checks whether or not a given node is a for loop. + * @param {ASTNode} block - A node to check. + * @returns {boolean} `true` when the node is a for loop. + */ +function isForLoop(block) { + return block.type === "ForInStatement" || + block.type === "ForOfStatement" || + block.type === "ForStatement"; +} + +/** + * Checks whether or not a given declarator node has its initializer. + * @param {ASTNode} node - A declarator node to check. + * @returns {boolean} `true` when the node has its initializer. + */ +function isInitialized(node) { + const declaration = node.parent; + const block = declaration.parent; + + if (isForLoop(block)) { + if (block.type === "ForStatement") { + return block.init === declaration; + } + return block.left === declaration; + } + return Boolean(node.init); +} + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "require or disallow initialization in variable declarations", + category: "Variables", + recommended: false + }, + + schema: { + anyOf: [ + { + type: "array", + items: [ + { + enum: ["always"] + } + ], + minItems: 0, + maxItems: 1 + }, + { + type: "array", + items: [ + { + enum: ["never"] + }, + { + type: "object", + properties: { + ignoreForLoopInit: { + type: "boolean" + } + }, + additionalProperties: false + } + ], + minItems: 0, + maxItems: 2 + } + ] + } + }, + + create(context) { + + const MODE_ALWAYS = "always", + MODE_NEVER = "never"; + + const mode = context.options[0] || MODE_ALWAYS; + const params = context.options[1] || {}; + + //-------------------------------------------------------------------------- + // Public API + //-------------------------------------------------------------------------- + + return { + "VariableDeclaration:exit"(node) { + + const kind = node.kind, + declarations = node.declarations; + + for (let i = 0; i < declarations.length; ++i) { + const declaration = declarations[i], + id = declaration.id, + initialized = isInitialized(declaration), + isIgnoredForLoop = params.ignoreForLoopInit && isForLoop(node.parent); + + if (id.type !== "Identifier") { + continue; + } + + if (mode === MODE_ALWAYS && !initialized) { + context.report({ + node: declaration, + message: "Variable '{{idName}}' should be initialized on declaration.", + data: { + idName: id.name + } + }); + } else if (mode === MODE_NEVER && kind !== "const" && initialized && !isIgnoredForLoop) { + context.report({ + node: declaration, + message: "Variable '{{idName}}' should not be initialized on declaration.", + data: { + idName: id.name + } + }); + } + } + } + }; + } +}; |