3 files changed, 495 insertions, 0 deletions
diff --git a/node_modules/@babel/plugin-transform-parameters/lib/index.js b/node_modules/@babel/plugin-transform-parameters/lib/index.js
new file mode 100644
index 00000000..9d21bad0
--- /dev/null
+++ b/node_modules/@babel/plugin-transform-parameters/lib/index.js
@@ -0,0 +1,46 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+
+function _helperPluginUtils() {
+  const data = require("@babel/helper-plugin-utils");
+
+  _helperPluginUtils = function _helperPluginUtils() {
+    return data;
+  };
+
+  return data;
+}
+
+var _params = _interopRequireDefault(require("./params"));
+
+var _rest = _interopRequireDefault(require("./rest"));
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+var _default = (0, _helperPluginUtils().declare)((api, options) => {
+  api.assertVersion(7);
+  const loose = options.loose;
+  return {
+    visitor: {
+      Function(path) {
+        if (path.isArrowFunctionExpression() && path.get("params").some(param => param.isRestElement() || param.isAssignmentPattern())) {
+          path.arrowFunctionToExpression();
+        }
+
+        const convertedRest = (0, _rest.default)(path);
+        const convertedParams = (0, _params.default)(path, loose);
+
+        if (convertedRest || convertedParams) {
+          path.scope.crawl();
+        }
+      }
+
+    }
+  };
+});
+
+exports.default = _default;
+\ No newline at end of file
diff --git a/node_modules/@babel/plugin-transform-parameters/lib/params.js b/node_modules/@babel/plugin-transform-parameters/lib/params.js
new file mode 100644
index 00000000..3563e08e
--- /dev/null
+++ b/node_modules/@babel/plugin-transform-parameters/lib/params.js
@@ -0,0 +1,163 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = convertFunctionParams;
+
+function _helperCallDelegate() {
+  const data = _interopRequireDefault(require("@babel/helper-call-delegate"));
+
+  _helperCallDelegate = function _helperCallDelegate() {
+    return data;
+  };
+
+  return data;
+}
+
+function _core() {
+  const data = require("@babel/core");
+
+  _core = function _core() {
+    return data;
+  };
+
+  return data;
+}
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+const buildDefaultParam = (0, _core().template)(`
+  let VARIABLE_NAME =
+    arguments.length > ARGUMENT_KEY && arguments[ARGUMENT_KEY] !== undefined ?
+      arguments[ARGUMENT_KEY]
+    :
+      DEFAULT_VALUE;
+`);
+const buildLooseDefaultParam = (0, _core().template)(`
+  if (ASSIGNMENT_IDENTIFIER === UNDEFINED) {
+    ASSIGNMENT_IDENTIFIER = DEFAULT_VALUE;
+  }
+`);
+const buildLooseDestructuredDefaultParam = (0, _core().template)(`
+  let ASSIGNMENT_IDENTIFIER = PARAMETER_NAME === UNDEFINED ? DEFAULT_VALUE : PARAMETER_NAME ;
+`);
+const buildSafeArgumentsAccess = (0, _core().template)(`
+  let $0 = arguments.length > $1 ? arguments[$1] : undefined;
+`);
+
+function isSafeBinding(scope, node) {
+  if (!scope.hasOwnBinding(node.name)) return true;
+
+  const _scope$getOwnBinding = scope.getOwnBinding(node.name),
+        kind = _scope$getOwnBinding.kind;
+
+  return kind === "param" || kind === "local";
+}
+
+const iifeVisitor = {
+  ReferencedIdentifier(path, state) {
+    const scope = path.scope,
+          node = path.node;
+
+    if (node.name === "eval" || !isSafeBinding(scope, node)) {
+      state.iife = true;
+      path.stop();
+    }
+  },
+
+  Scope(path) {
+    path.skip();
+  }
+
+};
+
+function convertFunctionParams(path, loose) {
+  const node = path.node,
+        scope = path.scope;
+  const state = {
+    iife: false,
+    scope: scope
+  };
+  const body = [];
+  const params = path.get("params");
+  let firstOptionalIndex = null;
+
+  for (let i = 0; i < params.length; i++) {
+    const param = params[i];
+
+    if (param.isAssignmentPattern() && loose) {
+      const left = param.get("left");
+      const right = param.get("right");
+      const undefinedNode = scope.buildUndefinedNode();
+
+      if (left.isIdentifier()) {
+        body.push(buildLooseDefaultParam({
+          ASSIGNMENT_IDENTIFIER: _core().types.cloneNode(left.node),
+          DEFAULT_VALUE: right.node,
+          UNDEFINED: undefinedNode
+        }));
+        param.replaceWith(left.node);
+      } else if (left.isObjectPattern() || left.isArrayPattern()) {
+        const paramName = scope.generateUidIdentifier();
+        body.push(buildLooseDestructuredDefaultParam({
+          ASSIGNMENT_IDENTIFIER: left.node,
+          DEFAULT_VALUE: right.node,
+          PARAMETER_NAME: _core().types.cloneNode(paramName),
+          UNDEFINED: undefinedNode
+        }));
+        param.replaceWith(paramName);
+      }
+    } else if (param.isAssignmentPattern()) {
+      if (firstOptionalIndex === null) firstOptionalIndex = i;
+      const left = param.get("left");
+      const right = param.get("right");
+
+      if (!state.iife) {
+        if (right.isIdentifier() && !isSafeBinding(scope, right.node)) {
+          state.iife = true;
+        } else {
+          right.traverse(iifeVisitor, state);
+        }
+      }
+
+      const defNode = buildDefaultParam({
+        VARIABLE_NAME: left.node,
+        DEFAULT_VALUE: right.node,
+        ARGUMENT_KEY: _core().types.numericLiteral(i)
+      });
+      body.push(defNode);
+    } else if (firstOptionalIndex !== null) {
+      const defNode = buildSafeArgumentsAccess([param.node, _core().types.numericLiteral(i)]);
+      body.push(defNode);
+    } else if (param.isObjectPattern() || param.isArrayPattern()) {
+      const uid = path.scope.generateUidIdentifier("ref");
+
+      const defNode = _core().types.variableDeclaration("let", [_core().types.variableDeclarator(param.node, uid)]);
+
+      body.push(defNode);
+      param.replaceWith(_core().types.cloneNode(uid));
+    }
+
+    if (!state.iife && !param.isIdentifier()) {
+      param.traverse(iifeVisitor, state);
+    }
+  }
+
+  if (body.length === 0) return false;
+
+  if (firstOptionalIndex !== null) {
+    node.params = node.params.slice(0, firstOptionalIndex);
+  }
+
+  path.ensureBlock();
+
+  if (state.iife) {
+    body.push((0, _helperCallDelegate().default)(path, scope));
+    path.set("body", _core().types.blockStatement(body));
+  } else {
+    path.get("body").unshiftContainer("body", body);
+  }
+
+  return true;
+}
+\ No newline at end of file
diff --git a/node_modules/@babel/plugin-transform-parameters/lib/rest.js b/node_modules/@babel/plugin-transform-parameters/lib/rest.js
new file mode 100644
index 00000000..82238e81
--- /dev/null
+++ b/node_modules/@babel/plugin-transform-parameters/lib/rest.js
@@ -0,0 +1,286 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = convertFunctionRest;
+
+function _core() {
+  const data = require("@babel/core");
+
+  _core = function _core() {
+    return data;
+  };
+
+  return data;
+}
+
+const buildRest = (0, _core().template)(`
+  for (var LEN = ARGUMENTS.length,
+           ARRAY = new Array(ARRAY_LEN),
+           KEY = START;
+       KEY < LEN;
+       KEY++) {
+    ARRAY[ARRAY_KEY] = ARGUMENTS[KEY];
+  }
+`);
+const restIndex = (0, _core().template)(`
+  (INDEX < OFFSET || ARGUMENTS.length <= INDEX) ? undefined : ARGUMENTS[INDEX]
+`);
+const restIndexImpure = (0, _core().template)(`
+  REF = INDEX, (REF < OFFSET || ARGUMENTS.length <= REF) ? undefined : ARGUMENTS[REF]
+`);
+const restLength = (0, _core().template)(`
+  ARGUMENTS.length <= OFFSET ? 0 : ARGUMENTS.length - OFFSET
+`);
+
+function referencesRest(path, state) {
+  if (path.node.name === state.name) {
+    return path.scope.bindingIdentifierEquals(state.name, state.outerBinding);
+  }
+
+  return false;
+}
+
+const memberExpressionOptimisationVisitor = {
+  Scope(path, state) {
+    if (!path.scope.bindingIdentifierEquals(state.name, state.outerBinding)) {
+      path.skip();
+    }
+  },
+
+  Flow(path) {
+    if (path.isTypeCastExpression()) return;
+    path.skip();
+  },
+
+  Function(path, state) {
+    const oldNoOptimise = state.noOptimise;
+    state.noOptimise = true;
+    path.traverse(memberExpressionOptimisationVisitor, state);
+    state.noOptimise = oldNoOptimise;
+    path.skip();
+  },
+
+  ReferencedIdentifier(path, state) {
+    const node = path.node;
+
+    if (node.name === "arguments") {
+      state.deopted = true;
+    }
+
+    if (!referencesRest(path, state)) return;
+
+    if (state.noOptimise) {
+      state.deopted = true;
+    } else {
+      const parentPath = path.parentPath;
+
+      if (parentPath.listKey === "params" && parentPath.key < state.offset) {
+        return;
+      }
+
+      if (parentPath.isMemberExpression({
+        object: node
+      })) {
+        const grandparentPath = parentPath.parentPath;
+        const argsOptEligible = !state.deopted && !(grandparentPath.isAssignmentExpression() && parentPath.node === grandparentPath.node.left || grandparentPath.isLVal() || grandparentPath.isForXStatement() || grandparentPath.isUpdateExpression() || grandparentPath.isUnaryExpression({
+          operator: "delete"
+        }) || (grandparentPath.isCallExpression() || grandparentPath.isNewExpression()) && parentPath.node === grandparentPath.node.callee);
+
+        if (argsOptEligible) {
+          if (parentPath.node.computed) {
+            if (parentPath.get("property").isBaseType("number")) {
+              state.candidates.push({
+                cause: "indexGetter",
+                path
+              });
+              return;
+            }
+          } else if (parentPath.node.property.name === "length") {
+            state.candidates.push({
+              cause: "lengthGetter",
+              path
+            });
+            return;
+          }
+        }
+      }
+
+      if (state.offset === 0 && parentPath.isSpreadElement()) {
+        const call = parentPath.parentPath;
+
+        if (call.isCallExpression() && call.node.arguments.length === 1) {
+          state.candidates.push({
+            cause: "argSpread",
+            path
+          });
+          return;
+        }
+      }
+
+      state.references.push(path);
+    }
+  },
+
+  BindingIdentifier(path, state) {
+    if (referencesRest(path, state)) {
+      state.deopted = true;
+    }
+  }
+
+};
+
+function hasRest(node) {
+  const length = node.params.length;
+  return length > 0 && _core().types.isRestElement(node.params[length - 1]);
+}
+
+function optimiseIndexGetter(path, argsId, offset) {
+  const offsetLiteral = _core().types.numericLiteral(offset);
+
+  let index;
+
+  if (_core().types.isNumericLiteral(path.parent.property)) {
+    index = _core().types.numericLiteral(path.parent.property.value + offset);
+  } else if (offset === 0) {
+    index = path.parent.property;
+  } else {
+    index = _core().types.binaryExpression("+", path.parent.property, _core().types.cloneNode(offsetLiteral));
+  }
+
+  const scope = path.scope;
+
+  if (!scope.isPure(index)) {
+    const temp = scope.generateUidIdentifierBasedOnNode(index);
+    scope.push({
+      id: temp,
+      kind: "var"
+    });
+    path.parentPath.replaceWith(restIndexImpure({
+      ARGUMENTS: argsId,
+      OFFSET: offsetLiteral,
+      INDEX: index,
+      REF: _core().types.cloneNode(temp)
+    }));
+  } else {
+    const parentPath = path.parentPath;
+    parentPath.replaceWith(restIndex({
+      ARGUMENTS: argsId,
+      OFFSET: offsetLiteral,
+      INDEX: index
+    }));
+    const offsetTestPath = parentPath.get("test").get("left");
+    const valRes = offsetTestPath.evaluate();
+
+    if (valRes.confident) {
+      if (valRes.value === true) {
+        parentPath.replaceWith(parentPath.scope.buildUndefinedNode());
+      } else {
+        parentPath.get("test").replaceWith(parentPath.get("test").get("right"));
+      }
+    }
+  }
+}
+
+function optimiseLengthGetter(path, argsId, offset) {
+  if (offset) {
+    path.parentPath.replaceWith(restLength({
+      ARGUMENTS: argsId,
+      OFFSET: _core().types.numericLiteral(offset)
+    }));
+  } else {
+    path.replaceWith(argsId);
+  }
+}
+
+function convertFunctionRest(path) {
+  const node = path.node,
+        scope = path.scope;
+  if (!hasRest(node)) return false;
+  const rest = node.params.pop().argument;
+
+  const argsId = _core().types.identifier("arguments");
+
+  const state = {
+    references: [],
+    offset: node.params.length,
+    argumentsNode: argsId,
+    outerBinding: scope.getBindingIdentifier(rest.name),
+    candidates: [],
+    name: rest.name,
+    deopted: false
+  };
+  path.traverse(memberExpressionOptimisationVisitor, state);
+
+  if (!state.deopted && !state.references.length) {
+    var _arr = state.candidates;
+
+    for (var _i = 0; _i < _arr.length; _i++) {
+      const _ref = _arr[_i];
+      const path = _ref.path,
+            cause = _ref.cause;
+
+      const clonedArgsId = _core().types.cloneNode(argsId);
+
+      switch (cause) {
+        case "indexGetter":
+          optimiseIndexGetter(path, clonedArgsId, state.offset);
+          break;
+
+        case "lengthGetter":
+          optimiseLengthGetter(path, clonedArgsId, state.offset);
+          break;
+
+        default:
+          path.replaceWith(clonedArgsId);
+      }
+    }
+
+    return true;
+  }
+
+  state.references = state.references.concat(state.candidates.map(({
+    path
+  }) => path));
+
+  const start = _core().types.numericLiteral(node.params.length);
+
+  const key = scope.generateUidIdentifier("key");
+  const len = scope.generateUidIdentifier("len");
+  let arrKey, arrLen;
+
+  if (node.params.length) {
+    arrKey = _core().types.binaryExpression("-", _core().types.cloneNode(key), _core().types.cloneNode(start));
+    arrLen = _core().types.conditionalExpression(_core().types.binaryExpression(">", _core().types.cloneNode(len), _core().types.cloneNode(start)), _core().types.binaryExpression("-", _core().types.cloneNode(len), _core().types.cloneNode(start)), _core().types.numericLiteral(0));
+  } else {
+    arrKey = _core().types.identifier(key.name);
+    arrLen = _core().types.identifier(len.name);
+  }
+
+  const loop = buildRest({
+    ARGUMENTS: argsId,
+    ARRAY_KEY: arrKey,
+    ARRAY_LEN: arrLen,
+    START: start,
+    ARRAY: rest,
+    KEY: key,
+    LEN: len
+  });
+
+  if (state.deopted) {
+    node.body.body.unshift(loop);
+  } else {
+    let target = path.getEarliestCommonAncestorFrom(state.references).getStatementParent();
+    target.findParent(path => {
+      if (path.isLoop()) {
+        target = path;
+      } else {
+        return path.isFunction();
+      }
+    });
+    target.insertBefore(loop);
+  }
+
+  return true;
+}
+\ No newline at end of file