template-curly-spacing.js 4.1 KB

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  1. /**
  2. * @fileoverview Rule to enforce spacing around embedded expressions of template strings
  3. * @author Toru Nagashima
  4. */
  5. "use strict";
  6. //------------------------------------------------------------------------------
  7. // Requirements
  8. //------------------------------------------------------------------------------
  9. const astUtils = require("./utils/ast-utils");
  10. //------------------------------------------------------------------------------
  11. // Helpers
  12. //------------------------------------------------------------------------------
  13. const OPEN_PAREN = /\$\{$/u;
  14. const CLOSE_PAREN = /^\}/u;
  15. //------------------------------------------------------------------------------
  16. // Rule Definition
  17. //------------------------------------------------------------------------------
  18. module.exports = {
  19. meta: {
  20. type: "layout",
  21. docs: {
  22. description: "require or disallow spacing around embedded expressions of template strings",
  23. category: "ECMAScript 6",
  24. recommended: false,
  25. url: "https://eslint.org/docs/rules/template-curly-spacing"
  26. },
  27. fixable: "whitespace",
  28. schema: [
  29. { enum: ["always", "never"] }
  30. ],
  31. messages: {
  32. expectedBefore: "Expected space(s) before '}'.",
  33. expectedAfter: "Expected space(s) after '${'.",
  34. unexpectedBefore: "Unexpected space(s) before '}'.",
  35. unexpectedAfter: "Unexpected space(s) after '${'."
  36. }
  37. },
  38. create(context) {
  39. const sourceCode = context.getSourceCode();
  40. const always = context.options[0] === "always";
  41. const prefix = always ? "expected" : "unexpected";
  42. /**
  43. * Checks spacing before `}` of a given token.
  44. * @param {Token} token A token to check. This is a Template token.
  45. * @returns {void}
  46. */
  47. function checkSpacingBefore(token) {
  48. const prevToken = sourceCode.getTokenBefore(token);
  49. if (prevToken &&
  50. CLOSE_PAREN.test(token.value) &&
  51. astUtils.isTokenOnSameLine(prevToken, token) &&
  52. sourceCode.isSpaceBetweenTokens(prevToken, token) !== always
  53. ) {
  54. context.report({
  55. loc: token.loc.start,
  56. messageId: `${prefix}Before`,
  57. fix(fixer) {
  58. if (always) {
  59. return fixer.insertTextBefore(token, " ");
  60. }
  61. return fixer.removeRange([
  62. prevToken.range[1],
  63. token.range[0]
  64. ]);
  65. }
  66. });
  67. }
  68. }
  69. /**
  70. * Checks spacing after `${` of a given token.
  71. * @param {Token} token A token to check. This is a Template token.
  72. * @returns {void}
  73. */
  74. function checkSpacingAfter(token) {
  75. const nextToken = sourceCode.getTokenAfter(token);
  76. if (nextToken &&
  77. OPEN_PAREN.test(token.value) &&
  78. astUtils.isTokenOnSameLine(token, nextToken) &&
  79. sourceCode.isSpaceBetweenTokens(token, nextToken) !== always
  80. ) {
  81. context.report({
  82. loc: {
  83. line: token.loc.end.line,
  84. column: token.loc.end.column - 2
  85. },
  86. messageId: `${prefix}After`,
  87. fix(fixer) {
  88. if (always) {
  89. return fixer.insertTextAfter(token, " ");
  90. }
  91. return fixer.removeRange([
  92. token.range[1],
  93. nextToken.range[0]
  94. ]);
  95. }
  96. });
  97. }
  98. }
  99. return {
  100. TemplateElement(node) {
  101. const token = sourceCode.getFirstToken(node);
  102. checkSpacingBefore(token);
  103. checkSpacingAfter(token);
  104. }
  105. };
  106. }
  107. };