add some packages

node_modules/babel-plugin-transform-simplify-comparison-operators/lib/index.js

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+"use strict";
+
+module.exports = function ({
+  types: t
+}) {
+  // custom implementation of getTypeAnnotation that fixes
+  // the type information that is lost during sequence expression transformation
+  // https://github.com/babel/minify/issues/323
+  function customTypeAnnotation(path) {
+    if (path.typeAnnotation) {
+      return path.typeAnnotation;
+    } // We are not handling the case of literals and other base types
+    // since they are already handled via getTypeAnnotation
+
+
+    const node = path.node;
+    const binding = path.parentPath.scope.getBinding(node.name);
+    const types = [];
+
+    if (binding && binding.constantViolations) {
+      if (binding.identifier.typeAnnotation) {
+        return binding.identifier.typeAnnotation;
+      }
+
+      if (binding.constantViolations) {
+        const violations = binding.constantViolations;
+        var _iteratorNormalCompletion = true;
+        var _didIteratorError = false;
+        var _iteratorError = undefined;
+
+        try {
+          for (var _iterator = violations[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
+            let violation = _step.value;
+            types.push(violation.getTypeAnnotation());
+          }
+        } catch (err) {
+          _didIteratorError = true;
+          _iteratorError = err;
+        } finally {
+          try {
+            if (!_iteratorNormalCompletion && _iterator.return != null) {
+              _iterator.return();
+            }
+          } finally {
+            if (_didIteratorError) {
+              throw _iteratorError;
+            }
+          }
+        }
+      }
+    }
+
+    if (types.length > 0) {
+      return t.createUnionTypeAnnotation(types);
+    }
+
+    return types;
+  } // Based on the type inference in Babel
+
+
+  function baseTypeStrictlyMatches(left, right) {
+    let leftTypes, rightTypes;
+
+    if (t.isIdentifier(left)) {
+      leftTypes = customTypeAnnotation(left);
+    } else if (t.isIdentifier(right)) {
+      rightTypes = customTypeAnnotation(right);
+    } // Early exit
+
+
+    if (t.isAnyTypeAnnotation(leftTypes) || t.isAnyTypeAnnotation(rightTypes)) {
+      return false;
+    }
+
+    leftTypes = [].concat(leftTypes, left.getTypeAnnotation());
+    rightTypes = [].concat(rightTypes, right.getTypeAnnotation());
+    leftTypes = t.createUnionTypeAnnotation(leftTypes);
+    rightTypes = t.createUnionTypeAnnotation(rightTypes);
+
+    if (!t.isAnyTypeAnnotation(leftTypes) && t.isFlowBaseAnnotation(leftTypes)) {
+      return leftTypes.type === rightTypes.type;
+    }
+  }
+
+  return {
+    name: "transform-simplify-comparison-operators",
+    visitor: {
+      // simplify comparison operations if we're 100% certain
+      // that each value will always be of the same type
+      BinaryExpression(path) {
+        const node = path.node;
+        const op = node.operator;
+
+        if (op !== "===" && op !== "!==") {
+          return;
+        }
+
+        const left = path.get("left");
+        const right = path.get("right");
+        const strictMatch = baseTypeStrictlyMatches(left, right);
+
+        if (strictMatch) {
+          node.operator = node.operator.slice(0, -1);
+        }
+      }
+
+    }
+  };
+};