From 0ad2eff2a46c28a877de1960a2dc5c15c0f94444 Mon Sep 17 00:00:00 2001 From: syeopite Date: Tue, 30 Jan 2024 15:25:45 -0800 Subject: [PATCH] WebVTT::Builder: Add logic to escape special chars --- spec/helpers/vtt/builder_spec.cr | 65 +++++++++++++++++++++----------- src/invidious/helpers/webvtt.cr | 16 +++++++- 2 files changed, 59 insertions(+), 22 deletions(-) diff --git a/spec/helpers/vtt/builder_spec.cr b/spec/helpers/vtt/builder_spec.cr index 7b543ddcb..dc1f4613c 100644 --- a/spec/helpers/vtt/builder_spec.cr +++ b/spec/helpers/vtt/builder_spec.cr @@ -1,34 +1,27 @@ require "../../spec_helper.cr" -MockLines = [ - { - "start_time": Time::Span.new(seconds: 1), - "end_time": Time::Span.new(seconds: 2), - "text": "Line 1", - }, - - { - "start_time": Time::Span.new(seconds: 2), - "end_time": Time::Span.new(seconds: 3), - "text": "Line 2", - }, -] +MockLines = ["Line 1", "Line 2"] +MockLinesWithEscapableCharacter = ["", "&Line 2>", '\u200E' + "Line\u200F 3", "\u00A0Line 4"] Spectator.describe "WebVTT::Builder" do it "correctly builds a vtt file" do result = WebVTT.build do |vtt| - MockLines.each do |line| - vtt.cue(line["start_time"], line["end_time"], line["text"]) + 2.times do |i| + vtt.cue( + Time::Span.new(seconds: i), + Time::Span.new(seconds: i + 1), + MockLines[i] + ) end end expect(result).to eq([ "WEBVTT", "", - "00:00:01.000 --> 00:00:02.000", + "00:00:00.000 --> 00:00:01.000", "Line 1", "", - "00:00:02.000 --> 00:00:03.000", + "00:00:01.000 --> 00:00:02.000", "Line 2", "", "", @@ -42,8 +35,12 @@ Spectator.describe "WebVTT::Builder" do } result = WebVTT.build(setting_fields) do |vtt| - MockLines.each do |line| - vtt.cue(line["start_time"], line["end_time"], line["text"]) + 2.times do |i| + vtt.cue( + Time::Span.new(seconds: i), + Time::Span.new(seconds: i + 1), + MockLines[i] + ) end end @@ -52,13 +49,39 @@ Spectator.describe "WebVTT::Builder" do "Kind: captions", "Language: en", "", - "00:00:01.000 --> 00:00:02.000", + "00:00:00.000 --> 00:00:01.000", "Line 1", "", - "00:00:02.000 --> 00:00:03.000", + "00:00:01.000 --> 00:00:02.000", "Line 2", "", "", ].join('\n')) end + + it "properly escapes characters" do + result = WebVTT.build do |vtt| + 4.times do |i| + vtt.cue(Time::Span.new(seconds: i), Time::Span.new(seconds: i + 1), MockLinesWithEscapableCharacter[i]) + end + end + + expect(result).to eq([ + "WEBVTT", + "", + "00:00:00.000 --> 00:00:01.000", + "<Line 1>", + "", + "00:00:01.000 --> 00:00:02.000", + "&Line 2>", + "", + "00:00:02.000 --> 00:00:03.000", + "‎Line‏ 3", + "", + "00:00:03.000 --> 00:00:04.000", + " Line 4", + "", + "", + ].join('\n')) + end end diff --git a/src/invidious/helpers/webvtt.cr b/src/invidious/helpers/webvtt.cr index 56f761edb..260d250fa 100644 --- a/src/invidious/helpers/webvtt.cr +++ b/src/invidious/helpers/webvtt.cr @@ -4,13 +4,23 @@ module WebVTT # A WebVTT builder generates WebVTT files private class Builder + # See https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API#cue_payload + private ESCAPE_SUBSTITUTIONS = { + '&' => "&", + '<' => "<", + '>' => ">", + '\u200E' => "‎", + '\u200F' => "‏", + '\u00A0' => " ", + } + def initialize(@io : IO) end # Writes an vtt cue with the specified time stamp and contents def cue(start_time : Time::Span, end_time : Time::Span, text : String) timestamp(start_time, end_time) - @io << text + @io << self.escape(text) @io << "\n\n" end @@ -29,6 +39,10 @@ module WebVTT @io << '.' << timestamp.milliseconds.to_s.rjust(3, '0') end + private def escape(text : String) : String + return text.gsub(ESCAPE_SUBSTITUTIONS) + end + def document(setting_fields : Hash(String, String)? = nil, &) @io << "WEBVTT\n"