tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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expressions.js (2204B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
      4 
      5 import { correctIndentation } from "./indentation";
      6 import { getGrip, getFront } from "./evaluation-result";
      7 
      8 const UNAVAILABLE_GRIP = { unavailable: true };
      9 
     10 /*
     11 * wrap the expression input in a try/catch so that it can be safely
     12 * evaluated.
     13 *
     14 * NOTE: we add line after the expression to protect against comments.
     15 */
     16 export function wrapExpression(input) {
     17  return correctIndentation(`
     18    try {
     19      ${input}
     20    } catch (e) {
     21      e
     22    }
     23  `);
     24 }
     25 
     26 function isUnavailable(value) {
     27  return (
     28    value &&
     29    !!value.isError &&
     30    (value.class === "ReferenceError" || value.class === "TypeError")
     31  );
     32 }
     33 
     34 /**
     35 *
     36 * @param {object} expression: Expression item as stored in state.expressions in reducers/expressions.js
     37 * @param {string} expression.input: evaluated expression string
     38 * @param {object} expression.value: evaluated expression result object as returned from ScriptCommand#execute
     39 * @param {object} expression.value.result: expression result, might be a primitive, a grip or a front
     40 * @param {object} expression.value.exception: expression result error, might be a primitive, a grip or a front
     41 * @returns {object} an object of the following shape:
     42 *                   - expressionResultGrip: A primitive or a grip
     43 *                   - expressionResultFront: An object front if it exists, or undefined
     44 */
     45 export function getExpressionResultGripAndFront(expression) {
     46  const { value } = expression;
     47 
     48  if (!value) {
     49    return { expressionResultGrip: UNAVAILABLE_GRIP };
     50  }
     51 
     52  const expressionResultReturn = value.exception || value.result;
     53  const valueGrip = getGrip(expressionResultReturn);
     54  if (valueGrip == null || isUnavailable(valueGrip)) {
     55    return { expressionResultGrip: UNAVAILABLE_GRIP };
     56  }
     57 
     58  if (valueGrip.isError) {
     59    const { name, message } = valueGrip.preview;
     60    return { expressionResultGrip: `${name}: ${message}` };
     61  }
     62 
     63  return {
     64    expressionResultGrip: valueGrip,
     65    expressionResultFront: getFront(expressionResultReturn),
     66  };
     67 }