error.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */

// ReactJS
const PropTypes = require("prop-types");
// Utils
const { getGripType, isGrip, wrapRender } = require("./rep-utils");
const { cleanFunctionName } = require("./function");
const { isLongString } = require("./string");
const { MODE } = require("./constants");

const dom = require("react-dom-factories");
const { span } = dom;
const IGNORED_SOURCE_URLS = ["debugger eval code"];

/**
 * Renders Error objects.
 */
ErrorRep.propTypes = {
  object: PropTypes.object.isRequired,
  // @TODO Change this to Object.values when supported in Node's version of V8
  mode: PropTypes.oneOf(Object.keys(MODE).map(key => MODE[key]))
};

function ErrorRep(props) {
  const object = props.object;
  const preview = object.preview;

  let name;
  if (preview && preview.name && preview.kind) {
    switch (preview.kind) {
      case "Error":
        name = preview.name;
        break;
      case "DOMException":
        name = preview.kind;
        break;
      default:
        throw new Error("Unknown preview kind for the Error rep.");
    }
  } else {
    name = "Error";
  }

  const content = [];

  if (props.mode === MODE.TINY) {
    content.push(name);
  } else {
    content.push(`${name}: "${preview.message}"`);
  }

  if (preview.stack && props.mode !== MODE.TINY) {
    content.push("\n", getStacktraceElements(props, preview));
  }

  return span(
    {
      "data-link-actor-id": object.actor,
      className: "objectBox-stackTrace"
    },
    content
  );
}

/**
 * Returns a React element reprensenting the Error stacktrace, i.e.
 * transform error.stack from:
 *
 * semicolon@debugger eval code:1:109
 * jkl@debugger eval code:1:63
 * asdf@debugger eval code:1:28
 * @debugger eval code:1:227
 *
 * Into a column layout:
 *
 * semicolon  (<anonymous>:8:10)
 * jkl        (<anonymous>:5:10)
 * asdf       (<anonymous>:2:10)
 *            (<anonymous>:11:1)
 */
function getStacktraceElements(props, preview) {
  const stack = [];
  if (!preview.stack) {
    return stack;
  }

  const isStacktraceALongString = isLongString(preview.stack);
  const stackString = isStacktraceALongString
    ? preview.stack.initial
    : preview.stack;

  stackString.split("\n").forEach((frame, index) => {
    if (!frame) {
      // Skip any blank lines
      return;
    }

    let functionName;
    let location;

    // Given the input: "functionName@scriptLocation:2:100"
    // Result: [
    //   "functionName@scriptLocation:2:100",
    //   "functionName",
    //   "scriptLocation:2:100"
    // ]
    const result = frame.match(/^(.*)@(.*)$/);
    if (result && result.length === 3) {
      functionName = result[1];

      // If the resource was loaded by base-loader.js, the location looks like:
      // resource://devtools/shared/base-loader.js -> resource://path/to/file.js .
      // What's needed is only the last part after " -> ".
      location = result[2].split(" -> ").pop();
    }

    if (!functionName) {
      functionName = "<anonymous>";
    }

    let onLocationClick;
    // Given the input: "scriptLocation:2:100"
    // Result:
    // ["scriptLocation:2:100", "scriptLocation", "2", "100"]
    const locationParts = location.match(/^(.*):(\d+):(\d+)$/);
    if (
      props.onViewSourceInDebugger &&
      location &&
      !IGNORED_SOURCE_URLS.includes(locationParts[1]) &&
      locationParts
    ) {
      const [, url, line, column] = locationParts;
      onLocationClick = e => {
        // Don't trigger ObjectInspector expand/collapse.
        e.stopPropagation();
        props.onViewSourceInDebugger({
          url,
          line: Number(line),
          column: Number(column)
        });
      };
    }

    stack.push(
      span(
        {
          key: `fn${index}`,
          className: "objectBox-stackTrace-fn"
        },
        cleanFunctionName(functionName)
      ),
      span(
        {
          key: `location${index}`,
          className: "objectBox-stackTrace-location",
          onClick: onLocationClick,
          title: onLocationClick
            ? `View source in debugger → ${location}`
            : undefined
        },
        location
      )
    );
  });

  if (isStacktraceALongString) {
    // Remove the last frame (i.e. 2 last elements in the array, the function
    // name and the location) which is certainly incomplete.
    // Can be removed when https://bugzilla.mozilla.org/show_bug.cgi?id=1448833
    // is fixed.
    stack.splice(-2);
  }

  return span(
    {
      key: "stack",
      className: "objectBox-stackTrace-grid"
    },
    stack
  );
}

// Registration
function supportsObject(object, noGrip = false) {
  if (noGrip === true || !isGrip(object)) {
    return false;
  }
  return (
    (object.preview && getGripType(object, noGrip) === "Error") ||
    object.class === "DOMException"
  );
}

// Exports from this module
module.exports = {
  rep: wrapRender(ErrorRep),
  supportsObject
};