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Diffstat (limited to 'tools/eslint/lib/rules/implicit-arrow-linebreak.js')
-rw-r--r-- | tools/eslint/lib/rules/implicit-arrow-linebreak.js | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/implicit-arrow-linebreak.js b/tools/eslint/lib/rules/implicit-arrow-linebreak.js new file mode 100644 index 0000000000..b8802f4de5 --- /dev/null +++ b/tools/eslint/lib/rules/implicit-arrow-linebreak.js @@ -0,0 +1,86 @@ +/** + * @fileoverview enforce the location of arrow function bodies + * @author Sharmila Jesupaul + */ +"use strict"; + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ +module.exports = { + meta: { + docs: { + description: "enforce the location of arrow function bodies", + category: "Stylistic Issues", + recommended: false + }, + fixable: "whitespace", + schema: [ + { + enum: ["beside", "below"] + } + ] + }, + + create(context) { + const sourceCode = context.getSourceCode(); + + //---------------------------------------------------------------------- + // Helpers + //---------------------------------------------------------------------- + /** + * Gets the applicable preference for a particular keyword + * @returns {string} The applicable option for the keyword, e.g. 'beside' + */ + function getOption() { + return context.options[0] || "beside"; + } + + /** + * Validates the location of an arrow function body + * @param {ASTNode} node The arrow function body + * @param {string} keywordName The applicable keyword name for the arrow function body + * @returns {void} + */ + function validateExpression(node) { + const option = getOption(); + + let tokenBefore = sourceCode.getTokenBefore(node.body); + const hasParens = tokenBefore.value === "("; + + if (node.type === "BlockStatement") { + return; + } + + let fixerTarget = node.body; + + if (hasParens) { + + // Gets the first token before the function body that is not an open paren + tokenBefore = sourceCode.getTokenBefore(node.body, token => token.value !== "("); + fixerTarget = sourceCode.getTokenAfter(tokenBefore); + } + + if (tokenBefore.loc.end.line === fixerTarget.loc.start.line && option === "below") { + context.report({ + node: fixerTarget, + message: "Expected a linebreak before this expression.", + fix: fixer => fixer.insertTextBefore(fixerTarget, "\n") + }); + } else if (tokenBefore.loc.end.line !== fixerTarget.loc.start.line && option === "beside") { + context.report({ + node: fixerTarget, + message: "Expected no linebreak before this expression.", + fix: fixer => fixer.replaceTextRange([tokenBefore.range[1], fixerTarget.range[0]], " ") + }); + } + } + + //---------------------------------------------------------------------- + // Public + //---------------------------------------------------------------------- + return { + ArrowFunctionExpression: node => validateExpression(node) + }; + } +}; |