eslint/lib/shared/deprecation-warnings.js

   1 /**
   2  * @fileoverview Provide the function that emits deprecation warnings.
   3  * @author Toru Nagashima <http://github.com/mysticatea>
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const path = require("path");
  12
  13 //------------------------------------------------------------------------------
  14 // Private
  15 //------------------------------------------------------------------------------
  16
  17 // Definitions for deprecation warnings.
  18 const deprecationWarningMessages = {
  19     ESLINT_LEGACY_ECMAFEATURES:
  20         "The 'ecmaFeatures' config file property is deprecated and has no effect."
  21 };
  22
  23 const sourceFileErrorCache = new Set();
  24
  25 /**
  26  * Emits a deprecation warning containing a given filepath. A new deprecation warning is emitted
  27  * for each unique file path, but repeated invocations with the same file path have no effect.
  28  * No warnings are emitted if the `--no-deprecation` or `--no-warnings` Node runtime flags are active.
  29  * @param {string} source The name of the configuration source to report the warning for.
  30  * @param {string} errorCode The warning message to show.
  31  * @returns {void}
  32  */
  33 function emitDeprecationWarning(source, errorCode) {
  34     const cacheKey = JSON.stringify({ source, errorCode });
  35
  36     if (sourceFileErrorCache.has(cacheKey)) {
  37         return;
  38     }
  39
  40     sourceFileErrorCache.add(cacheKey);
  41
  42     const rel = path.relative(process.cwd(), source);
  43     const message = deprecationWarningMessages[errorCode];
  44
  45     process.emitWarning(
  46         `${message} (found in "${rel}")`,
  47         "DeprecationWarning",
  48         errorCode
  49     );
  50 }
  51
  52 //------------------------------------------------------------------------------
  53 // Public Interface
  54 //------------------------------------------------------------------------------
  55
  56 module.exports = {
  57     emitDeprecationWarning
  58 };