importsToResolve.js 1.8 KB

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  1. 'use strict';
  2. const path = require('path');
  3. const utils = require('loader-utils');
  4. const matchModuleImport = /^~([^/]+|@[^/]+[/][^/]+)$/;
  5. /**
  6. * When libsass tries to resolve an import, it uses a special algorithm.
  7. * Since the sass-loader uses webpack to resolve the modules, we need to simulate that algorithm. This function
  8. * returns an array of import paths to try. The last entry in the array is always the original url
  9. * to enable straight-forward webpack.config aliases.
  10. *
  11. * @param {string} url
  12. * @returns {Array<string>}
  13. */
  14. function importsToResolve(url) {
  15. const request = utils.urlToRequest(url);
  16. // Keep in mind: ext can also be something like '.datepicker' when the true extension is omitted and the filename contains a dot.
  17. // @see https://github.com/webpack-contrib/sass-loader/issues/167
  18. const ext = path.extname(request);
  19. if (matchModuleImport.test(url)) {
  20. return [request, url];
  21. }
  22. // libsass' import algorithm works like this:
  23. // In case there is a file extension...
  24. // - If the file is a CSS-file, do not include it all, but just link it via @import url().
  25. // - The exact file name must match (no auto-resolving of '_'-modules).
  26. if (ext === '.css') {
  27. return [];
  28. }
  29. if (ext === '.scss' || ext === '.sass') {
  30. return [request, url];
  31. }
  32. // In case there is no file extension...
  33. // - Prefer modules starting with '_'.
  34. // - File extension precedence: .scss, .sass, .css.
  35. const basename = path.basename(request);
  36. if (basename.charAt(0) === '_') {
  37. return [`${request}.scss`, `${request}.sass`, `${request}.css`, url];
  38. }
  39. const dirname = path.dirname(request);
  40. return [
  41. `${dirname}/_${basename}.scss`,
  42. `${dirname}/_${basename}.sass`,
  43. `${dirname}/_${basename}.css`,
  44. `${request}.scss`,
  45. `${request}.sass`,
  46. `${request}.css`,
  47. url,
  48. ];
  49. }
  50. module.exports = importsToResolve;