index.js 7.8 KB

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  1. 'use strict';
  2. Object.defineProperty(exports, '__esModule', { value: true });
  3. var helperPluginUtils = require('@babel/helper-plugin-utils');
  4. var syntaxOptionalChaining = require('@babel/plugin-syntax-optional-chaining');
  5. var core = require('@babel/core');
  6. var helperSkipTransparentExpressionWrappers = require('@babel/helper-skip-transparent-expression-wrappers');
  7. function willPathCastToBoolean(path) {
  8. const maybeWrapped = findOutermostTransparentParent(path);
  9. const {
  10. node,
  11. parentPath
  12. } = maybeWrapped;
  13. if (parentPath.isLogicalExpression()) {
  14. const {
  15. operator,
  16. right
  17. } = parentPath.node;
  18. if (operator === "&&" || operator === "||" || operator === "??" && node === right) {
  19. return willPathCastToBoolean(parentPath);
  20. }
  21. }
  22. if (parentPath.isSequenceExpression()) {
  23. const {
  24. expressions
  25. } = parentPath.node;
  26. if (expressions[expressions.length - 1] === node) {
  27. return willPathCastToBoolean(parentPath);
  28. } else {
  29. return true;
  30. }
  31. }
  32. return parentPath.isConditional({
  33. test: node
  34. }) || parentPath.isUnaryExpression({
  35. operator: "!"
  36. }) || parentPath.isLoop({
  37. test: node
  38. });
  39. }
  40. function findOutermostTransparentParent(path) {
  41. let maybeWrapped = path;
  42. path.findParent(p => {
  43. if (!helperSkipTransparentExpressionWrappers.isTransparentExprWrapper(p.node)) return true;
  44. maybeWrapped = p;
  45. });
  46. return maybeWrapped;
  47. }
  48. const {
  49. ast
  50. } = core.template.expression;
  51. function isSimpleMemberExpression(expression) {
  52. expression = helperSkipTransparentExpressionWrappers.skipTransparentExprWrapperNodes(expression);
  53. return core.types.isIdentifier(expression) || core.types.isSuper(expression) || core.types.isMemberExpression(expression) && !expression.computed && isSimpleMemberExpression(expression.object);
  54. }
  55. function needsMemoize(path) {
  56. let optionalPath = path;
  57. const {
  58. scope
  59. } = path;
  60. while (optionalPath.isOptionalMemberExpression() || optionalPath.isOptionalCallExpression()) {
  61. const {
  62. node
  63. } = optionalPath;
  64. const childPath = helperSkipTransparentExpressionWrappers.skipTransparentExprWrappers(optionalPath.isOptionalMemberExpression() ? optionalPath.get("object") : optionalPath.get("callee"));
  65. if (node.optional) {
  66. return !scope.isStatic(childPath.node);
  67. }
  68. optionalPath = childPath;
  69. }
  70. }
  71. function transform(path, {
  72. pureGetters,
  73. noDocumentAll
  74. }) {
  75. const {
  76. scope
  77. } = path;
  78. const maybeWrapped = findOutermostTransparentParent(path);
  79. const {
  80. parentPath
  81. } = maybeWrapped;
  82. const willReplacementCastToBoolean = willPathCastToBoolean(maybeWrapped);
  83. let isDeleteOperation = false;
  84. const parentIsCall = parentPath.isCallExpression({
  85. callee: maybeWrapped.node
  86. }) && path.isOptionalMemberExpression();
  87. const optionals = [];
  88. let optionalPath = path;
  89. if (scope.path.isPattern() && needsMemoize(optionalPath)) {
  90. path.replaceWith(core.template.ast`(() => ${path.node})()`);
  91. return;
  92. }
  93. while (optionalPath.isOptionalMemberExpression() || optionalPath.isOptionalCallExpression()) {
  94. const {
  95. node
  96. } = optionalPath;
  97. if (node.optional) {
  98. optionals.push(node);
  99. }
  100. if (optionalPath.isOptionalMemberExpression()) {
  101. optionalPath.node.type = "MemberExpression";
  102. optionalPath = helperSkipTransparentExpressionWrappers.skipTransparentExprWrappers(optionalPath.get("object"));
  103. } else if (optionalPath.isOptionalCallExpression()) {
  104. optionalPath.node.type = "CallExpression";
  105. optionalPath = helperSkipTransparentExpressionWrappers.skipTransparentExprWrappers(optionalPath.get("callee"));
  106. }
  107. }
  108. let replacementPath = path;
  109. if (parentPath.isUnaryExpression({
  110. operator: "delete"
  111. })) {
  112. replacementPath = parentPath;
  113. isDeleteOperation = true;
  114. }
  115. for (let i = optionals.length - 1; i >= 0; i--) {
  116. const node = optionals[i];
  117. const isCall = core.types.isCallExpression(node);
  118. const chainWithTypes = isCall ? node.callee : node.object;
  119. const chain = helperSkipTransparentExpressionWrappers.skipTransparentExprWrapperNodes(chainWithTypes);
  120. let ref;
  121. let check;
  122. if (isCall && core.types.isIdentifier(chain, {
  123. name: "eval"
  124. })) {
  125. check = ref = chain;
  126. node.callee = core.types.sequenceExpression([core.types.numericLiteral(0), ref]);
  127. } else if (pureGetters && isCall && isSimpleMemberExpression(chain)) {
  128. check = ref = node.callee;
  129. } else {
  130. ref = scope.maybeGenerateMemoised(chain);
  131. if (ref) {
  132. check = core.types.assignmentExpression("=", core.types.cloneNode(ref), chainWithTypes);
  133. isCall ? node.callee = ref : node.object = ref;
  134. } else {
  135. check = ref = chainWithTypes;
  136. }
  137. }
  138. if (isCall && core.types.isMemberExpression(chain)) {
  139. if (pureGetters && isSimpleMemberExpression(chain)) {
  140. node.callee = chainWithTypes;
  141. } else {
  142. const {
  143. object
  144. } = chain;
  145. let context;
  146. if (core.types.isSuper(object)) {
  147. context = core.types.thisExpression();
  148. } else {
  149. const memoized = scope.maybeGenerateMemoised(object);
  150. if (memoized) {
  151. context = memoized;
  152. chain.object = core.types.assignmentExpression("=", memoized, object);
  153. } else {
  154. context = object;
  155. }
  156. }
  157. node.arguments.unshift(core.types.cloneNode(context));
  158. node.callee = core.types.memberExpression(node.callee, core.types.identifier("call"));
  159. }
  160. }
  161. let replacement = replacementPath.node;
  162. if (i === 0 && parentIsCall) {
  163. var _baseRef;
  164. const object = helperSkipTransparentExpressionWrappers.skipTransparentExprWrapperNodes(replacement.object);
  165. let baseRef;
  166. if (!pureGetters || !isSimpleMemberExpression(object)) {
  167. baseRef = scope.maybeGenerateMemoised(object);
  168. if (baseRef) {
  169. replacement.object = core.types.assignmentExpression("=", baseRef, object);
  170. }
  171. }
  172. replacement = core.types.callExpression(core.types.memberExpression(replacement, core.types.identifier("bind")), [core.types.cloneNode((_baseRef = baseRef) != null ? _baseRef : object)]);
  173. }
  174. if (willReplacementCastToBoolean) {
  175. const nonNullishCheck = noDocumentAll ? ast`${core.types.cloneNode(check)} != null` : ast`
  176. ${core.types.cloneNode(check)} !== null && ${core.types.cloneNode(ref)} !== void 0`;
  177. replacementPath.replaceWith(core.types.logicalExpression("&&", nonNullishCheck, replacement));
  178. replacementPath = helperSkipTransparentExpressionWrappers.skipTransparentExprWrappers(replacementPath.get("right"));
  179. } else {
  180. const nullishCheck = noDocumentAll ? ast`${core.types.cloneNode(check)} == null` : ast`
  181. ${core.types.cloneNode(check)} === null || ${core.types.cloneNode(ref)} === void 0`;
  182. const returnValue = isDeleteOperation ? ast`true` : ast`void 0`;
  183. replacementPath.replaceWith(core.types.conditionalExpression(nullishCheck, returnValue, replacement));
  184. replacementPath = helperSkipTransparentExpressionWrappers.skipTransparentExprWrappers(replacementPath.get("alternate"));
  185. }
  186. }
  187. }
  188. var index = helperPluginUtils.declare((api, options) => {
  189. var _api$assumption, _api$assumption2;
  190. api.assertVersion(7);
  191. const {
  192. loose = false
  193. } = options;
  194. const noDocumentAll = (_api$assumption = api.assumption("noDocumentAll")) != null ? _api$assumption : loose;
  195. const pureGetters = (_api$assumption2 = api.assumption("pureGetters")) != null ? _api$assumption2 : loose;
  196. return {
  197. name: "proposal-optional-chaining",
  198. inherits: syntaxOptionalChaining.default,
  199. visitor: {
  200. "OptionalCallExpression|OptionalMemberExpression"(path) {
  201. transform(path, {
  202. noDocumentAll,
  203. pureGetters
  204. });
  205. }
  206. }
  207. };
  208. });
  209. exports["default"] = index;
  210. exports.transform = transform;
  211. //# sourceMappingURL=index.js.map