1 files changed, 369 insertions, 0 deletions
diff --git a/node_modules/regenerator-transform/src/visit.js b/node_modules/regenerator-transform/src/visit.js
new file mode 100644
index 00000000..a2744b38
--- /dev/null
+++ b/node_modules/regenerator-transform/src/visit.js
@@ -0,0 +1,369 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+"use strict";
+
+import assert from "assert";
+import { hoist } from "./hoist";
+import { Emitter } from "./emit";
+import replaceShorthandObjectMethod from "./replaceShorthandObjectMethod";
+import * as util from "./util";
+
+exports.getVisitor = ({ types: t }) => ({
+  Method(path, state) {
+    let node = path.node;
+
+    if (!shouldRegenerate(node, state)) return;
+
+    const container = t.functionExpression(
+      null,
+      [],
+      t.cloneNode(node.body, false),
+      node.generator,
+      node.async,
+    );
+
+    path.get("body").set("body", [
+      t.returnStatement(
+        t.callExpression(container, []),
+      ),
+    ]);
+
+    // Regardless of whether or not the wrapped function is a an async method
+    // or generator the outer function should not be
+    node.async = false;
+    node.generator = false;
+
+    // Unwrap the wrapper IIFE's environment so super and this and such still work.
+    path
+      .get("body.body.0.argument.callee")
+      .unwrapFunctionEnvironment();
+  },
+  Function: {
+    exit: util.wrapWithTypes(t, function(path, state) {
+      let node = path.node;
+
+      if (!shouldRegenerate(node, state)) return;
+
+      // if this is an ObjectMethod, we need to convert it to an ObjectProperty
+      path = replaceShorthandObjectMethod(path);
+      node = path.node;
+
+      let contextId = path.scope.generateUidIdentifier("context");
+      let argsId = path.scope.generateUidIdentifier("args");
+
+      path.ensureBlock();
+      let bodyBlockPath = path.get("body");
+
+      if (node.async) {
+        bodyBlockPath.traverse(awaitVisitor);
+      }
+
+      bodyBlockPath.traverse(functionSentVisitor, {
+        context: contextId
+      });
+
+      let outerBody = [];
+      let innerBody = [];
+
+      bodyBlockPath.get("body").forEach(function(childPath) {
+        let node = childPath.node;
+        if (t.isExpressionStatement(node) &&
+            t.isStringLiteral(node.expression)) {
+          // Babylon represents directives like "use strict" as elements
+          // of a bodyBlockPath.node.directives array, but they could just
+          // as easily be represented (by other parsers) as traditional
+          // string-literal-valued expression statements, so we need to
+          // handle that here. (#248)
+          outerBody.push(node);
+        } else if (node && node._blockHoist != null) {
+          outerBody.push(node);
+        } else {
+          innerBody.push(node);
+        }
+      });
+
+      if (outerBody.length > 0) {
+        // Only replace the inner body if we actually hoisted any statements
+        // to the outer body.
+        bodyBlockPath.node.body = innerBody;
+      }
+
+      let outerFnExpr = getOuterFnExpr(path);
+      // Note that getOuterFnExpr has the side-effect of ensuring that the
+      // function has a name (so node.id will always be an Identifier), even
+      // if a temporary name has to be synthesized.
+      t.assertIdentifier(node.id);
+      let innerFnId = t.identifier(node.id.name + "$");
+
+      // Turn all declarations into vars, and replace the original
+      // declarations with equivalent assignment expressions.
+      let vars = hoist(path);
+
+      let context = {
+        usesThis: false,
+        usesArguments: false,
+        getArgsId: () => t.clone(argsId),
+      };
+      path.traverse(argumentsThisVisitor, context);
+
+      if (context.usesArguments) {
+        vars = vars || t.variableDeclaration("var", []);
+        vars.declarations.push(t.variableDeclarator(
+          t.clone(argsId),
+          t.identifier("arguments"),
+        ));
+      }
+
+      let emitter = new Emitter(contextId);
+      emitter.explode(path.get("body"));
+
+      if (vars && vars.declarations.length > 0) {
+        outerBody.push(vars);
+      }
+
+      let wrapArgs = [emitter.getContextFunction(innerFnId)];
+      let tryLocsList = emitter.getTryLocsList();
+
+      if (node.generator) {
+        wrapArgs.push(outerFnExpr);
+      } else if (context.usesThis || tryLocsList || node.async) {
+        // Async functions that are not generators don't care about the
+        // outer function because they don't need it to be marked and don't
+        // inherit from its .prototype.
+        wrapArgs.push(t.nullLiteral());
+      }
+      if (context.usesThis) {
+        wrapArgs.push(t.thisExpression());
+      } else if (tryLocsList || node.async) {
+        wrapArgs.push(t.nullLiteral());
+      }
+      if (tryLocsList) {
+        wrapArgs.push(tryLocsList);
+      } else if (node.async) {
+        wrapArgs.push(t.nullLiteral());
+      }
+
+      if (node.async) {
+        // Rename any locally declared "Promise" variable,
+        // to use the global one.
+        let currentScope = path.scope;
+        do {
+          if (currentScope.hasOwnBinding("Promise")) currentScope.rename("Promise");
+        } while (currentScope = currentScope.parent);
+
+        wrapArgs.push(t.identifier("Promise"));
+      }
+
+      let wrapCall = t.callExpression(
+        util.runtimeProperty(node.async ? "async" : "wrap"),
+        wrapArgs
+      );
+
+      outerBody.push(t.returnStatement(wrapCall));
+      node.body = t.blockStatement(outerBody);
+      // We injected a few new variable declarations (for every hoisted var),
+      // so we need to add them to the scope.
+      path.get("body.body").forEach(p => p.scope.registerDeclaration(p));
+
+      const oldDirectives = bodyBlockPath.node.directives;
+      if (oldDirectives) {
+        // Babylon represents directives like "use strict" as elements of
+        // a bodyBlockPath.node.directives array. (#248)
+        node.body.directives = oldDirectives;
+      }
+
+      let wasGeneratorFunction = node.generator;
+      if (wasGeneratorFunction) {
+        node.generator = false;
+      }
+
+      if (node.async) {
+        node.async = false;
+      }
+
+      if (wasGeneratorFunction && t.isExpression(node)) {
+        util.replaceWithOrRemove(path, t.callExpression(util.runtimeProperty("mark"), [node]))
+        path.addComment("leading", "#__PURE__");
+      }
+
+      const insertedLocs = emitter.getInsertedLocs();
+
+      path.traverse({
+        NumericLiteral(path) {
+          if (!insertedLocs.has(path.node)) {
+            return;
+          }
+
+          path.replaceWith(t.numericLiteral(path.node.value));
+        },
+      })
+
+      // Generators are processed in 'exit' handlers so that regenerator only has to run on
+      // an ES5 AST, but that means traversal will not pick up newly inserted references
+      // to things like 'regeneratorRuntime'. To avoid this, we explicitly requeue.
+      path.requeue();
+    })
+  }
+});
+
+// Check if a node should be transformed by regenerator
+function shouldRegenerate(node, state) {
+  if (node.generator) {
+    if (node.async) {
+      // Async generator
+      return state.opts.asyncGenerators !== false;
+    } else {
+      // Plain generator
+      return state.opts.generators !== false;
+    }
+  } else if (node.async) {
+    // Async function
+    return state.opts.async !== false;
+  } else {
+    // Not a generator or async function.
+    return false;
+  }
+}
+
+// Given a NodePath for a Function, return an Expression node that can be
+// used to refer reliably to the function object from inside the function.
+// This expression is essentially a replacement for arguments.callee, with
+// the key advantage that it works in strict mode.
+function getOuterFnExpr(funPath) {
+  const t = util.getTypes();
+  let node = funPath.node;
+  t.assertFunction(node);
+
+  if (!node.id) {
+    // Default-exported function declarations, and function expressions may not
+    // have a name to reference, so we explicitly add one.
+    node.id = funPath.scope.parent.generateUidIdentifier("callee");
+  }
+
+  if (node.generator && // Non-generator functions don't need to be marked.
+      t.isFunctionDeclaration(node)) {
+    // Return the identifier returned by runtime.mark(<node.id>).
+    return getMarkedFunctionId(funPath);
+  }
+
+  return t.clone(node.id);
+}
+
+const markInfo = new WeakMap();
+
+function getMarkInfo(node) {
+  if (!markInfo.has(node)) {
+    markInfo.set(node, {});
+  }
+  return markInfo.get(node);
+}
+
+function getMarkedFunctionId(funPath) {
+  const t = util.getTypes();
+  const node = funPath.node;
+  t.assertIdentifier(node.id);
+
+  const blockPath = funPath.findParent(function (path) {
+    return path.isProgram() || path.isBlockStatement();
+  });
+
+  if (!blockPath) {
+    return node.id;
+  }
+
+  const block = blockPath.node;
+  assert.ok(Array.isArray(block.body));
+
+  const info = getMarkInfo(block);
+  if (!info.decl) {
+    info.decl = t.variableDeclaration("var", []);
+    blockPath.unshiftContainer("body", info.decl);
+    info.declPath = blockPath.get("body.0");
+  }
+
+  assert.strictEqual(info.declPath.node, info.decl);
+
+  // Get a new unique identifier for our marked variable.
+  const markedId = blockPath.scope.generateUidIdentifier("marked");
+  const markCallExp = t.callExpression(
+    util.runtimeProperty("mark"),
+    [t.clone(node.id)]
+  );
+
+  const index = info.decl.declarations.push(
+    t.variableDeclarator(markedId, markCallExp)
+  ) - 1;
+
+  const markCallExpPath =
+    info.declPath.get("declarations." + index + ".init");
+
+  assert.strictEqual(markCallExpPath.node, markCallExp);
+
+  markCallExpPath.addComment("leading", "#__PURE__");
+
+  return t.clone(markedId);
+}
+
+let argumentsThisVisitor = {
+  "FunctionExpression|FunctionDeclaration|Method": function(path) {
+    path.skip();
+  },
+
+  Identifier: function(path, state) {
+    if (path.node.name === "arguments" && util.isReference(path)) {
+      util.replaceWithOrRemove(path, state.getArgsId());
+      state.usesArguments = true;
+    }
+  },
+
+  ThisExpression: function(path, state) {
+    state.usesThis = true;
+  }
+};
+
+let functionSentVisitor = {
+  MetaProperty(path) {
+    let { node } = path;
+
+    if (node.meta.name === "function" &&
+        node.property.name === "sent") {
+      const t = util.getTypes();
+      util.replaceWithOrRemove(
+        path,
+        t.memberExpression(
+          t.clone(this.context),
+          t.identifier("_sent")
+        )
+      );
+    }
+  }
+};
+
+let awaitVisitor = {
+  Function: function(path) {
+    path.skip(); // Don't descend into nested function scopes.
+  },
+
+  AwaitExpression: function(path) {
+    const t = util.getTypes();
+
+    // Convert await expressions to yield expressions.
+    let argument = path.node.argument;
+
+    // Transforming `await x` to `yield regeneratorRuntime.awrap(x)`
+    // causes the argument to be wrapped in such a way that the runtime
+    // can distinguish between awaited and merely yielded values.
+    util.replaceWithOrRemove(path, t.yieldExpression(
+      t.callExpression(
+        util.runtimeProperty("awrap"),
+        [argument]
+      ),
+      false
+    ));
+  }
+};