js: config.js: Fix newline character handling in data-isso-* i18n strings

Replace escaped newline characters in data-isso attribute values with actual newline characters to ensure correct parsing and display.

Fixes #912

Author: pkvach

CHANGES.rst

@@ -27,13 +27,15 @@ Bugfixes & Improvements
 - Prevent auto creation of invalid links in comments (`#995`_, pkvach)
 - Fix W3C Validation issues (`#999`_, pkvach)
 - Handle deleted comments in Disqus migration (`#994`_, pkvach)
+- Fix newline character handling in data-isso-* i18n strings (`#992`_, pkvach)
 
 .. _#951: https://github.com/posativ/isso/pull/951
 .. _#967: https://github.com/posativ/isso/pull/967
 .. _#983: https://github.com/posativ/isso/pull/983
 .. _#995: https://github.com/isso-comments/isso/pull/995
 .. _#999: https://github.com/isso-comments/isso/pull/999
 .. _#994: https://github.com/isso-comments/isso/pull/994
+.. _#992: https://github.com/isso-comments/isso/pull/992
 
 0.13.1.dev0 (2023-02-05)
 ------------------------

isso/js/app/config.js

@@ -16,6 +16,10 @@ for (var i = 0; i < js.length; i++) {
     for (var j = 0; j < js[i].attributes.length; j++) {
         var attr = js[i].attributes[j];
         if (/^data-isso-/.test(attr.name)) {
+
+            // Replace escaped newline characters in the attribute value with actual newline characters
+            const attrValue = attr.value.replace(/\\n/g, '\n');
+
             try {
                 // Normalize underscores to dashes so that language-specific
                 // strings can be caught better later on,
@@ -27,11 +31,11 @@ for (var i = 0; i < js.length; i++) {
                 // not follow that convention, convert to lowercase here anyway.
                 config[attr.name.substring(10)
                        .replace(/_/g, '-')
-                       .toLowerCase()] = JSON.parse(attr.value);
+                       .toLowerCase()] = JSON.parse(attrValue);
             } catch (ex) {
                 config[attr.name.substring(10)
                        .replace(/_/g, '-')
-                       .toLowerCase()] = attr.value;
+                       .toLowerCase()] = attrValue;
             }
         }
     }

isso/js/tests/unit/config.test.js

@@ -9,6 +9,11 @@
 
 "use strict";
 
+beforeEach(() => {
+  jest.resetModules();
+  document.body.innerHTML = '';
+});
+
 test("Client configuration - no languages", () => {
   // Mock navigator.languages = []
   global.languages = jest.spyOn(navigator, "languages", "get")
@@ -35,3 +40,21 @@ test("Client configuration - no languages", () => {
 
   expect(config["langs"]).toStrictEqual(expected_langs);
 });
+
+test("data-isso-* i18n strings should be accepted with newline characters", () => {
+
+  document.body.innerHTML =
+      '<div id=isso-thread></div>' +
+      // Note: `src` and `data-isso` need to be set,
+      // else `api` fails to initialize!
+      '<script src="http://isso.api/js/embed.min.js"'
+      + ' data-isso="/"'
+      + '</script>';
+
+  var script_tag = document.getElementsByTagName('script')[0];
+  script_tag.setAttributeNS(null, 'data-isso-num-comments-text-en', "One comment\\n{{ n }} comments");
+
+  const config = require("app/config");
+
+  expect(config['num-comments-text-en']).toMatch("One comment\n{{ n }} comments");
+});