parse-statements.js 3.0 KB

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  1. "use strict"
  2. // external tooling
  3. const valueParser = require("postcss-value-parser")
  4. // extended tooling
  5. const { stringify } = valueParser
  6. function split(params, start) {
  7. const list = []
  8. const last = params.reduce((item, node, index) => {
  9. if (index < start) return ""
  10. if (node.type === "div" && node.value === ",") {
  11. list.push(item)
  12. return ""
  13. }
  14. return item + stringify(node)
  15. }, "")
  16. list.push(last)
  17. return list
  18. }
  19. module.exports = function (result, styles) {
  20. const statements = []
  21. let nodes = []
  22. styles.each(node => {
  23. let stmt
  24. if (node.type === "atrule") {
  25. if (node.name === "import") stmt = parseImport(result, node)
  26. else if (node.name === "media") stmt = parseMedia(result, node)
  27. else if (node.name === "charset") stmt = parseCharset(result, node)
  28. }
  29. if (stmt) {
  30. if (nodes.length) {
  31. statements.push({
  32. type: "nodes",
  33. nodes,
  34. media: [],
  35. })
  36. nodes = []
  37. }
  38. statements.push(stmt)
  39. } else nodes.push(node)
  40. })
  41. if (nodes.length) {
  42. statements.push({
  43. type: "nodes",
  44. nodes,
  45. media: [],
  46. })
  47. }
  48. return statements
  49. }
  50. function parseMedia(result, atRule) {
  51. const params = valueParser(atRule.params).nodes
  52. return {
  53. type: "media",
  54. node: atRule,
  55. media: split(params, 0),
  56. }
  57. }
  58. function parseCharset(result, atRule) {
  59. if (atRule.prev()) {
  60. return result.warn("@charset must precede all other statements", {
  61. node: atRule,
  62. })
  63. }
  64. return {
  65. type: "charset",
  66. node: atRule,
  67. media: [],
  68. }
  69. }
  70. function parseImport(result, atRule) {
  71. let prev = atRule.prev()
  72. if (prev) {
  73. do {
  74. if (
  75. prev.type !== "comment" &&
  76. (prev.type !== "atrule" ||
  77. (prev.name !== "import" && prev.name !== "charset"))
  78. ) {
  79. return result.warn(
  80. "@import must precede all other statements (besides @charset)",
  81. { node: atRule }
  82. )
  83. }
  84. prev = prev.prev()
  85. } while (prev)
  86. }
  87. if (atRule.nodes) {
  88. return result.warn(
  89. "It looks like you didn't end your @import statement correctly. " +
  90. "Child nodes are attached to it.",
  91. { node: atRule }
  92. )
  93. }
  94. const params = valueParser(atRule.params).nodes
  95. const stmt = {
  96. type: "import",
  97. node: atRule,
  98. media: [],
  99. }
  100. // prettier-ignore
  101. if (
  102. !params.length ||
  103. (
  104. params[0].type !== "string" ||
  105. !params[0].value
  106. ) &&
  107. (
  108. params[0].type !== "function" ||
  109. params[0].value !== "url" ||
  110. !params[0].nodes.length ||
  111. !params[0].nodes[0].value
  112. )
  113. ) {
  114. return result.warn(`Unable to find uri in '${ atRule.toString() }'`, {
  115. node: atRule,
  116. })
  117. }
  118. if (params[0].type === "string") stmt.uri = params[0].value
  119. else stmt.uri = params[0].nodes[0].value
  120. stmt.fullUri = stringify(params[0])
  121. if (params.length > 2) {
  122. if (params[1].type !== "space") {
  123. return result.warn("Invalid import media statement", { node: atRule })
  124. }
  125. stmt.media = split(params, 2)
  126. }
  127. return stmt
  128. }