Java Code Examples for com.google.javascript.rhino.Node#hasOneChild()

/**
 * @param nameNode A name node
 * @return The JSDocInfo for the name node
 */
static JSDocInfo getInfoForNameNode(Node nameNode) {
  JSDocInfo info = null;
  Node parent = null;
  if (nameNode != null) {
    info = nameNode.getJSDocInfo();
    parent = nameNode.getParent();
  }

  if (info == null && parent != null &&
      ((parent.getType() == Token.VAR && parent.hasOneChild()) ||
        parent.getType() == Token.FUNCTION)) {
    info = parent.getJSDocInfo();
  }
  return info;
}
 

/**
 * @return Whether the node is a block with a single statement that is
 *     an expression.
 */
private boolean isFoldableExpressBlock(Node n) {
  if (n.getType() == Token.BLOCK) {
    if (n.hasOneChild()) {
      Node maybeExpr = n.getFirstChild();
        // IE has a bug where event handlers behave differently when
        // their return value is used vs. when their return value is in
        // an EXPR_RESULT. It's pretty freaking weird. See:
        // http://code.google.com/p/closure-compiler/issues/detail?id=291
        // We try to detect this case, and not fold EXPR_RESULTs
        // into other expressions.

          // We only have to worry about methods with an implicit 'this'
          // param, or this doesn't happen.

        return NodeUtil.isExpressionNode(maybeExpr);
    }
  }

  return false;
}
 

/**
 * Visit a node in the global scope, and add anything it declares to the
 * global symbol table.
 *
 * @param t The current traversal.
 * @param n The node being visited.
 * @param parent The parent of n
 */
@Override public void visit(NodeTraversal t, Node n, Node parent) {
  super.visit(t, n, parent);

  switch (n.getType()) {

    case Token.VAR:
      // Handle typedefs.
      if (n.hasOneChild()) {
        checkForTypedef(t, n.getFirstChild(), n.getJSDocInfo());
      }
      break;
  }
}
 

/**
 * @return Whether the node is a single return statement.
 */
private boolean isReturnExpression(Node n) {
  if (n.isReturn()) {
    return n.hasOneChild();
  }
  return false;
}
 

/**
 * @return function return value node if function body contains a
 * single return statement.  Otherwise, null.
 */
protected final Node maybeGetSingleReturnRValue(Node functionNode) {
  Node body = functionNode.getLastChild();
  if (!body.hasOneChild()) {
    return null;
  }

  Node statement = body.getFirstChild();
  if (statement.isReturn()) {
    return statement.getFirstChild();
  }
  return null;
}
 

/**
 * Checks if the function matches the pattern:
 *   function(<value>, <rest>) {this.<name> = <value>}
 * and returns <name> if a match is found.
 *
 * @return STRING node that is the RHS of a this property get; or null.
 */
private Node getSetPropertyName(Node functionNode) {
  Node body = functionNode.getLastChild();
  if (!body.hasOneChild()) {
    return null;
  }

  Node argList = functionNode.getFirstChild().getNext();
  Node paramNode = argList.getFirstChild();
  if (paramNode == null) {
    return null;
  }

  Node statement = body.getFirstChild();
  if (!NodeUtil.isExprAssign(statement)) {
    return null;
  }

  Node assign = statement.getFirstChild();
  Node lhs = assign.getFirstChild();
  if (lhs.isGetProp() && lhs.getFirstChild().isThis()) {
    Node rhs = assign.getLastChild();
    if (rhs.isName() &&
        rhs.getString().equals(paramNode.getString())) {
      Node propertyName = lhs.getLastChild();
      return propertyName;
    }
  }
  return null;
}
 

/**
 * Visit a node in the global scope, and add anything it declares to the
 * global symbol table.
 *
 * @param t The current traversal.
 * @param n The node being visited.
 * @param parent The parent of n
 */
@Override public void visit(NodeTraversal t, Node n, Node parent) {
  super.visit(t, n, parent);

  switch (n.getType()) {

    case Token.VAR:
      // Handle typedefs.
      if (n.hasOneChild()) {
        checkForTypedef(t, n.getFirstChild(), n.getJSDocInfo());
      }
      break;
  }
}
 

/**
 * Checks if the function matches the pattern:
 *   function(<value>, <rest>) {this.<name> = <value>}
 * and returns <name> if a match is found.
 *
 * @return STRING node that is the rhs of a this property get; or null.
 */
private Node getSetPropertyName(Node functionNode) {
  Node body = functionNode.getLastChild();
  if (!body.hasOneChild()) {
    return null;
  }

  Node argList = functionNode.getFirstChild().getNext();
  Node paramNode = argList.getFirstChild();
  if (paramNode == null) {
    return null;
  }

  Node statement = body.getFirstChild();
  if (!NodeUtil.isExprAssign(statement)) {
    return null;
  }

  Node assign = statement.getFirstChild();
  Node lhs = assign.getFirstChild();
  if (NodeUtil.isGetProp(lhs) && NodeUtil.isThis(lhs.getFirstChild())) {
    Node rhs = assign.getLastChild();
    if (NodeUtil.isName(rhs) &&
        rhs.getString().equals(paramNode.getString())) {
      Node propertyName = lhs.getLastChild();
      return propertyName;
    }
  }
  return null;
}
 

/**
 * Visits a VAR node.
 *
 * @param t The node traversal object that supplies context, such as the
 * scope chain to use in name lookups as well as error reporting.
 * @param n The node being visited.
 */
private void visitVar(NodeTraversal t, Node n) {
  // TODO(nicksantos): Fix this so that the doc info always shows up
  // on the NAME node. We probably want to wait for the parser
  // merge to fix this.
  JSDocInfo varInfo = n.hasOneChild() ? n.getJSDocInfo() : null;
  for (Node name : n.children()) {
    Node value = name.getFirstChild();
    // A null var would indicate a bug in the scope creation logic.
    Var var = t.getScope().getVar(name.getString());

    if (value != null) {
      JSType valueType = getJSType(value);
      JSType nameType = var.getType();
      nameType = (nameType == null) ? getNativeType(UNKNOWN_TYPE) : nameType;

      JSDocInfo info = name.getJSDocInfo();
      if (info == null) {
        info = varInfo;
      }
      if (info != null && info.hasEnumParameterType()) {
        // var.getType() can never be null, this would indicate a bug in the
        // scope creation logic.
        checkEnumInitializer(
            t, value,
            info.getEnumParameterType().evaluate(t.getScope(), typeRegistry));
      } else if (var.isTypeInferred()) {
        ensureTyped(t, name, valueType);
      } else {
        validator.expectCanAssignTo(
            t, value, valueType, nameType, "initializing variable");
      }
    }
  }
}
 

/**
 * @return Whether the node is a single return statement.
 */
private boolean isReturnExpression(Node n) {
  if (n.isReturn()) {
    return n.hasOneChild();
  }
  return false;
}
 

@Override
public void remove() {
  Node parent = nameNode.getParent();
  if (parent.getType() == Token.FUNCTION || parent.hasOneChild()) {
    NodeUtil.removeChild(parent.getParent(), parent);
  } else {
    Preconditions.checkState(parent.getType() == Token.VAR);
    parent.removeChild(nameNode);
  }
}
 

/**
 * Checks if the function matches the pattern:
 *   function(<value>, <rest>) {this.<name> = <value>}
 * and returns <name> if a match is found.
 *
 * @return STRING node that is the rhs of a this property get; or null.
 */
private Node getSetPropertyName(Node functionNode) {
  Node body = functionNode.getLastChild();
  if (!body.hasOneChild()) {
    return null;
  }

  Node argList = functionNode.getFirstChild().getNext();
  Node paramNode = argList.getFirstChild();
  if (paramNode == null) {
    return null;
  }

  Node statement = body.getFirstChild();
  if (!NodeUtil.isExprAssign(statement)) {
    return null;
  }

  Node assign = statement.getFirstChild();
  Node lhs = assign.getFirstChild();
  if (NodeUtil.isGetProp(lhs) && NodeUtil.isThis(lhs.getFirstChild())) {
    Node rhs = assign.getLastChild();
    if (NodeUtil.isName(rhs) &&
        rhs.getString().equals(paramNode.getString())) {
      Node propertyName = lhs.getLastChild();
      return propertyName;
    }
  }
  return null;
}
 

/**
 * @return Whether the node is a block with a single statement that is
 *     an return.
 */
private boolean isReturnExpressBlock(Node n) {
  if (n.getType() == Token.BLOCK) {
    if (n.hasOneChild()) {
      Node first = n.getFirstChild();
      if (first.getType() == Token.RETURN) {
        return first.hasOneChild();
      }
    }
  }

  return false;
}
 

/** Find the best JSDoc for the given node. */
static JSDocInfo getBestJSDocInfo(Node n) {
  JSDocInfo info = n.getJSDocInfo();
  if (info == null) {
    Node parent = n.getParent();
    if (parent == null) {
      return null;
    }

    if (parent.isName()) {
      return getBestJSDocInfo(parent);
    } else if (parent.isAssign()) {
      return parent.getJSDocInfo();
    } else if (isObjectLitKey(parent, parent.getParent())) {
      return parent.getJSDocInfo();
    } else if (parent.isFunction()) {
      return parent.getJSDocInfo();
    } else if (parent.isVar() && parent.hasOneChild()) {
      return parent.getJSDocInfo();
    } else if ((parent.isHook() && parent.getFirstChild() != n) ||
               parent.isOr() ||
               parent.isAnd() ||
               (parent.isComma() && parent.getFirstChild() != n)) {
      return getBestJSDocInfo(parent);
    }
  }
  return info;
}
 

/**
 * Visits a VAR node.
 *
 * @param t The node traversal object that supplies context, such as the
 * scope chain to use in name lookups as well as error reporting.
 * @param n The node being visited.
 */
private void visitVar(NodeTraversal t, Node n) {
  // TODO(nicksantos): Fix this so that the doc info always shows up
  // on the NAME node. We probably want to wait for the parser
  // merge to fix this.
  JSDocInfo varInfo = n.hasOneChild() ? n.getJSDocInfo() : null;
  for (Node name : n.children()) {
    Node value = name.getFirstChild();
    // A null var would indicate a bug in the scope creation logic.
    Var var = t.getScope().getVar(name.getString());

    if (value != null) {
      JSType valueType = getJSType(value);
      JSType nameType = var.getType();
      nameType = (nameType == null) ? getNativeType(UNKNOWN_TYPE) : nameType;

      JSDocInfo info = name.getJSDocInfo();
      if (info == null) {
        info = varInfo;
      }

      checkEnumAlias(t, info, value);
      if (var.isTypeInferred()) {
        ensureTyped(t, name, valueType);
      } else {
        validator.expectCanAssignTo(
            t, value, valueType, nameType, "initializing variable");
      }
    }
  }
}
 

private boolean containsObject(Node typedefNode) {
  Token typedefToken = typedefNode.getToken();
  if (typedefToken == Token.LC) {
    return true;
  }

  if ((typedefToken == Token.QMARK || typedefToken == Token.BANG)
      && typedefNode.hasOneChild()) {
    // child Node is a simple type or a LC
    return containsObject(typedefNode.getFirstChild());
  }

  return false;
}
 

@Override
public void remove() {
  Node parent = nameNode.getParent();
  if (parent.getType() == Token.FUNCTION || parent.hasOneChild()) {
    NodeUtil.removeChild(parent.getParent(), parent);
  } else {
    Preconditions.checkState(parent.getType() == Token.VAR);
    parent.removeChild(nameNode);
  }
}
 

/**
 * @return Whether the node is a block with a single statement that is
 *     an expression.
 */
private boolean isFoldableExpressBlock(Node n) {
  if (n.isBlock()) {
    if (n.hasOneChild()) {
      Node maybeExpr = n.getFirstChild();
      if (maybeExpr.isExprResult()) {
        // IE has a bug where event handlers behave differently when
        // their return value is used vs. when their return value is in
        // an EXPR_RESULT. It's pretty freaking weird. See:
        // http://code.google.com/p/closure-compiler/issues/detail?id=291
        // We try to detect this case, and not fold EXPR_RESULTs
        // into other expressions.
        if (maybeExpr.getFirstChild().isCall()) {
          Node calledFn = maybeExpr.getFirstChild().getFirstChild();

          // We only have to worry about methods with an implicit 'this'
          // param, or this doesn't happen.
          if (calledFn.isGetElem()) {
            return false;
          } else if (calledFn.isGetProp() &&
                     calledFn.getLastChild().getString().startsWith("on")) {
            return false;
          }
        }

        return true;
      }
      return false;
    }
  }

  return false;
}
 

/**
 * Visit a node in the global scope, and add anything it declares to the
 * global symbol table.
 *
 * @param t The current traversal.
 * @param n The node being visited.
 * @param parent The parent of n
 */
@Override public void visit(NodeTraversal t, Node n, Node parent) {
  super.visit(t, n, parent);

  switch (n.getType()) {

    case Token.VAR:
      // Handle typedefs.
      if (n.hasOneChild()) {
        checkForTypedef(t, n.getFirstChild(), n.getJSDocInfo());
      }
      break;
  }
}
 

/**
 * Visits a VAR node.
 *
 * @param t The node traversal object that supplies context, such as the
 * scope chain to use in name lookups as well as error reporting.
 * @param n The node being visited.
 */
private void visitVar(NodeTraversal t, Node n) {
  // TODO(nicksantos): Fix this so that the doc info always shows up
  // on the NAME node. We probably want to wait for the parser
  // merge to fix this.
  JSDocInfo varInfo = n.hasOneChild() ? n.getJSDocInfo() : null;
  for (Node name : n.children()) {
    Node value = name.getFirstChild();
    // A null var would indicate a bug in the scope creation logic.
    Var var = t.getScope().getVar(name.getString());

    if (value != null) {
      JSType valueType = getJSType(value);
      JSType nameType = var.getType();
      nameType = (nameType == null) ? getNativeType(UNKNOWN_TYPE) : nameType;

      JSDocInfo info = name.getJSDocInfo();
      if (info == null) {
        info = varInfo;
      }

      checkEnumAlias(t, info, value);
      if (var.isTypeInferred()) {
        ensureTyped(t, name, valueType);
      } else {
        validator.expectCanAssignTo(
            t, value, valueType, nameType, "initializing variable");
      }
    }
  }
}