@agoric/babel-parser/lib/parser/comments.js

A JavaScript parser

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _base = _interopRequireDefault(require("./base"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function last(stack) {
  return stack[stack.length - 1];
}

class CommentsParser extends _base.default {
  addComment(comment) {
    if (this.filename) comment.loc.filename = this.filename;
    this.state.trailingComments.push(comment);
    this.state.leadingComments.push(comment);
  }

  adjustCommentsAfterTrailingComma(node, elements, takeAllComments) {
    if (this.state.leadingComments.length === 0) {
      return;
    }

    let lastElement = null;
    let i = elements.length;

    while (lastElement === null && i > 0) {
      lastElement = elements[--i];
    }

    if (lastElement === null) {
      return;
    }

    for (let j = 0; j < this.state.leadingComments.length; j++) {
      if (this.state.leadingComments[j].end < this.state.commentPreviousNode.end) {
        this.state.leadingComments.splice(j, 1);
        j--;
      }
    }

    const newTrailingComments = [];

    for (let i = 0; i < this.state.leadingComments.length; i++) {
      const leadingComment = this.state.leadingComments[i];

      if (leadingComment.end < node.end) {
        newTrailingComments.push(leadingComment);

        if (!takeAllComments) {
          this.state.leadingComments.splice(i, 1);
          i--;
        }
      } else {
        if (node.trailingComments === undefined) {
          node.trailingComments = [];
        }

        node.trailingComments.push(leadingComment);
      }
    }

    if (takeAllComments) this.state.leadingComments = [];

    if (newTrailingComments.length > 0) {
      lastElement.trailingComments = newTrailingComments;
    } else if (lastElement.trailingComments !== undefined) {
      lastElement.trailingComments = [];
    }
  }

  processComment(node) {
    if (node.type === "Program" && node.body.length > 0) return;
    const stack = this.state.commentStack;
    let firstChild, lastChild, trailingComments, i, j;

    if (this.state.trailingComments.length > 0) {
      if (this.state.trailingComments[0].start >= node.end) {
        trailingComments = this.state.trailingComments;
        this.state.trailingComments = [];
      } else {
        this.state.trailingComments.length = 0;
      }
    } else if (stack.length > 0) {
      const lastInStack = last(stack);

      if (lastInStack.trailingComments && lastInStack.trailingComments[0].start >= node.end) {
        trailingComments = lastInStack.trailingComments;
        delete lastInStack.trailingComments;
      }
    }

    if (stack.length > 0 && last(stack).start >= node.start) {
      firstChild = stack.pop();
    }

    while (stack.length > 0 && last(stack).start >= node.start) {
      lastChild = stack.pop();
    }

    if (!lastChild && firstChild) lastChild = firstChild;

    if (firstChild) {
      switch (node.type) {
        case "ObjectExpression":
          this.adjustCommentsAfterTrailingComma(node, node.properties);
          break;

        case "ObjectPattern":
          this.adjustCommentsAfterTrailingComma(node, node.properties, true);
          break;

        case "CallExpression":
          this.adjustCommentsAfterTrailingComma(node, node.arguments);
          break;

        case "ArrayExpression":
          this.adjustCommentsAfterTrailingComma(node, node.elements);
          break;

        case "ArrayPattern":
          this.adjustCommentsAfterTrailingComma(node, node.elements, true);
          break;
      }
    } else if (this.state.commentPreviousNode && (this.state.commentPreviousNode.type === "ImportSpecifier" && node.type !== "ImportSpecifier" || this.state.commentPreviousNode.type === "ExportSpecifier" && node.type !== "ExportSpecifier")) {
      this.adjustCommentsAfterTrailingComma(node, [this.state.commentPreviousNode]);
    }

    if (lastChild) {
      if (lastChild.leadingComments) {
        if (lastChild !== node && lastChild.leadingComments.length > 0 && last(lastChild.leadingComments).end <= node.start) {
          node.leadingComments = lastChild.leadingComments;
          delete lastChild.leadingComments;
        } else {
          for (i = lastChild.leadingComments.length - 2; i >= 0; --i) {
            if (lastChild.leadingComments[i].end <= node.start) {
              node.leadingComments = lastChild.leadingComments.splice(0, i + 1);
              break;
            }
          }
        }
      }
    } else if (this.state.leadingComments.length > 0) {
      if (last(this.state.leadingComments).end <= node.start) {
        if (this.state.commentPreviousNode) {
          for (j = 0; j < this.state.leadingComments.length; j++) {
            if (this.state.leadingComments[j].end < this.state.commentPreviousNode.end) {
              this.state.leadingComments.splice(j, 1);
              j--;
            }
          }
        }

        if (this.state.leadingComments.length > 0) {
          node.leadingComments = this.state.leadingComments;
          this.state.leadingComments = [];
        }
      } else {
        for (i = 0; i < this.state.leadingComments.length; i++) {
          if (this.state.leadingComments[i].end > node.start) {
            break;
          }
        }

        const leadingComments = this.state.leadingComments.slice(0, i);

        if (leadingComments.length) {
          node.leadingComments = leadingComments;
        }

        trailingComments = this.state.leadingComments.slice(i);

        if (trailingComments.length === 0) {
          trailingComments = null;
        }
      }
    }

    this.state.commentPreviousNode = node;

    if (trailingComments) {
      if (trailingComments.length && trailingComments[0].start >= node.start && last(trailingComments).end <= node.end) {
        node.innerComments = trailingComments;
      } else {
        node.trailingComments = trailingComments;
      }
    }

    stack.push(node);
  }

}

exports.default = CommentsParser;