diff options
Diffstat (limited to 'node_modules/babel-plugin-transform-remove-undefined/lib/index.js')
| -rw-r--r-- | node_modules/babel-plugin-transform-remove-undefined/lib/index.js | 249 |
1 files changed, 0 insertions, 249 deletions
diff --git a/node_modules/babel-plugin-transform-remove-undefined/lib/index.js b/node_modules/babel-plugin-transform-remove-undefined/lib/index.js deleted file mode 100644 index 0b09c1d7..00000000 --- a/node_modules/babel-plugin-transform-remove-undefined/lib/index.js +++ /dev/null @@ -1,249 +0,0 @@ -"use strict"; - -const evaluate = require("babel-helper-evaluate-path"); - -function isPureAndUndefined(rval, { - tdz, - scope = { - hasBinding: () => false - } -} = {}) { - if (rval.isIdentifier() && rval.node.name === "undefined") { - // deopt right away if undefined is a local binding - if (scope.hasBinding(rval.node.name, true - /* no globals */ - )) { - return false; - } - - return true; - } - - if (!rval.isPure()) { - return false; - } - - const evaluation = evaluate(rval, { - tdz - }); - return evaluation.confident === true && evaluation.value === undefined; -} - -function getLoopParent(path, scopeParent) { - const parent = path.findParent(p => p.isLoop() || p === scopeParent); // don't traverse higher than the function the var is defined in. - - return parent === scopeParent ? null : parent; -} - -function getFunctionParent(path, scopeParent) { - const parent = path.findParent(p => p.isFunction()); // don't traverse higher than the function the var is defined in. - - return parent === scopeParent ? null : parent; -} - -function getFunctionReferences(path, scopeParent, references = new Set()) { - for (let func = getFunctionParent(path, scopeParent); func; func = getFunctionParent(func, scopeParent)) { - const id = func.node.id; - const binding = id && func.scope.getBinding(id.name); - - if (!binding) { - continue; - } - - binding.referencePaths.forEach(path => { - if (!references.has(path)) { - references.add(path); - getFunctionReferences(path, scopeParent, references); - } - }); - } - - return references; -} - -function hasViolation(declarator, scope, start) { - const binding = scope.getBinding(declarator.node.id.name); - - if (!binding) { - return true; - } - - const scopeParent = declarator.getFunctionParent(); - const violation = binding.constantViolations.some(v => { - // https://github.com/babel/minify/issues/630 - if (!v.node) { - return false; - } // return 'true' if we cannot guarantee the violation references - // the initialized identifier after - - - const violationStart = v.node.start; - - if (violationStart === undefined || violationStart < start) { - return true; - } - - const references = getFunctionReferences(v, scopeParent); - var _iteratorNormalCompletion = true; - var _didIteratorError = false; - var _iteratorError = undefined; - - try { - for (var _iterator = references[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) { - const ref = _step.value; - - if (ref.node.start === undefined || ref.node.start < start) { - return true; - } - } - } catch (err) { - _didIteratorError = true; - _iteratorError = err; - } finally { - try { - if (!_iteratorNormalCompletion && _iterator.return != null) { - _iterator.return(); - } - } finally { - if (_didIteratorError) { - throw _iteratorError; - } - } - } - - for (let loop = getLoopParent(declarator, scopeParent); loop; loop = getLoopParent(loop, scopeParent)) { - if (loop.node.end === undefined || loop.node.end > violationStart) { - return true; - } - } - }); - return violation; -} - -module.exports = function () { - return { - name: "transform-remove-undefined", - visitor: { - SequenceExpression(path, { - opts: { - tdz - } = {} - }) { - const expressions = path.get("expressions"); - - for (let i = 0; i < expressions.length; i++) { - const expr = expressions[i]; - if (!isPureAndUndefined(expr, { - tdz, - scope: path.scope - })) continue; // last value - - if (i === expressions.length - 1) { - if (path.parentPath.isExpressionStatement()) { - expr.remove(); - } - } else { - expr.remove(); - } - } - }, - - ReturnStatement(path, { - opts: { - tdz - } = {} - }) { - if (path.node.argument !== null) { - if (isPureAndUndefined(path.get("argument"), { - tdz, - scope: path.scope - })) { - path.node.argument = null; - } - } - }, - - VariableDeclaration(path, { - opts: { - tdz - } = {} - }) { - switch (path.node.kind) { - case "const": - break; - - case "let": - var _iteratorNormalCompletion2 = true; - var _didIteratorError2 = false; - var _iteratorError2 = undefined; - - try { - for (var _iterator2 = path.get("declarations")[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) { - const declarator = _step2.value; - - if (isPureAndUndefined(declarator.get("init"), { - tdz - })) { - declarator.node.init = null; - } - } - } catch (err) { - _didIteratorError2 = true; - _iteratorError2 = err; - } finally { - try { - if (!_iteratorNormalCompletion2 && _iterator2.return != null) { - _iterator2.return(); - } - } finally { - if (_didIteratorError2) { - throw _iteratorError2; - } - } - } - - break; - - case "var": - const start = path.node.start; - - if (start === undefined) { - // This is common for plugin-generated nodes - break; - } - - const scope = path.scope; - var _iteratorNormalCompletion3 = true; - var _didIteratorError3 = false; - var _iteratorError3 = undefined; - - try { - for (var _iterator3 = path.get("declarations")[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) { - const declarator = _step3.value; - - if (isPureAndUndefined(declarator.get("init")) && !hasViolation(declarator, scope, start)) { - declarator.node.init = null; - } - } - } catch (err) { - _didIteratorError3 = true; - _iteratorError3 = err; - } finally { - try { - if (!_iteratorNormalCompletion3 && _iterator3.return != null) { - _iterator3.return(); - } - } finally { - if (_didIteratorError3) { - throw _iteratorError3; - } - } - } - - break; - } - } - - } - }; -};
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