[screen modes] fix: explicit handling of screen modes

Escape sequences that set screen modes were not handled
Now they are explicitly handled, and ignored.

.changelog_entries/2e97ab2c3597636c8da399451aa57812.json

@@ -0,0 +1 @@
+{"type":"Added","tickets":[],"description":"added a CHANGELOG.md file","tags":[]}

.changelog_entries/34e99410c2fe5f6f718294dda8a5c098.json

@@ -0,0 +1 @@
+{"type":"Fixed","tickets":[],"description":"fixed indexing error when escape code included no integers","tags":[]}

.changelog_entries/9a8c11ee5c165b78734f8293c31ec0a3.json

@@ -0,0 +1 @@
+{"type":"Added","tickets":[],"description":"added specific non-handling of screen modes","tags":[]}

CHANGELOG.md

@@ -0,0 +1,55 @@
+## [1.3.6] - 2022-10-08
+### Added
+*  added a CHANGELOG.md file
+*  added specific non-handling of screen modes
+
+### Fixed
+*  fixed indexing error when escape code included no integers
+
+## [1.3.5] - 2021-02-05
+### Changed
+*  Output no longer includes useless spans.
+
+### Fixed
+*  better handling of non-display code amidst display ones
+
+## [1.3.4] - 2021-02-05
+### Changed
+*  now supports building under Crystal v0.35.1
+
+### Fixed
+*  fixed missing end span edge case
+
+## [1.3.3] - 2018-10-01
+## [1.3.2] - 2018-10-01
+### Fixed
+*  Corrected bug where the ends of escape sequences were not being correctly detected
+
+## [1.3.1] - 2018-09-03
+### Deprecated
+* [\[4\]](https://github.com/masukomi/oho/issues/4) corrects detection and handling of rgb color escape sequences
+
+## [1.3.0] - 2018-06-15
+### Added
+*  Added Support for ITU's T.416 / 8613-6  color codes
+
+## [1.2.0] - 2018-06-05
+### Added
+*  Added support for customer styling via -s arg
+
+### Fixed
+*  further corrections to default background and foreground handling
+
+## [1.1.1] - 2018-06-05
+### Fixed
+*  Corrected problem where requesting --help resulted in double output
+*  Corrected background and foreground color handling
+
+## [1.1.0] - 2018-05-26
+### Added
+*  Added print media CSS for better PDF conversions
+
+### Fixed
+*  simplified build.sh to remove some git complications
+
+## [1.0.0] - 2018-05-25

README.md

@@ -95,6 +95,19 @@ crystal build src/oho.cr
 An `oho` executable will be created in the current directory. Just move that
 into your PATH and follow the Usage instructions.
 
+
+## Caveats
+There are many, _many_ escape sequences that are used in terminals. Oho supports ANSI 3/4 bit (basic and high intensity), 8 bit, 
+& 24 bit color codes as well as ITU's T.416 / 8613-6  color codes. 
+
+"Screen mode" escape sequences are _not_ supported. In general, this isn't going to be an issue.
+For example: `^[=5;7h` would tell a terminal to render as 320 x 200 in Black & White mode. 
+To support that would require reformatting your text, and making a judgement call about which 
+colors should be converted to black, and which to white. Currently oho does not address 
+formatting issues or make judgement calls about colors. If, however, you feel like implementing this, 
+Pull Requests will be happily accepted.
+
+
 ## Development
 
 If you're adding new functionality or fixing a bug in existing functionality

spec/oho/color_escape_code_spec.cr

@@ -63,6 +63,41 @@ describe Oho::ColorEscapeCode do
       "</span><span style=\"font-weight: bold; opacity: 0.5; font-style: italic; text-decoration: underline; display: none; background-color: aqua; \">"))
   end
 
+  it "should not blow up when it encounters private use codes" do
+    ec = Oho::ColorEscapeCode.new("[?1h", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters ? screen mode codes" do
+    ec = Oho::ColorEscapeCode.new("[?7h", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters = screen mode codes" do
+    ec = Oho::ColorEscapeCode.new("[=1;7h", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters = screen mode codes 2" do
+    ec = Oho::ColorEscapeCode.new("[=0h", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters ? screen mode reset codes" do
+    ec = Oho::ColorEscapeCode.new("[?7l", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters = screen mode reset codes" do
+    ec = Oho::ColorEscapeCode.new("[=1;7l", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
+  it "should not blow up when it encounters = screen mode reset codes 2" do
+    ec = Oho::ColorEscapeCode.new("[=0l", default_options) #background
+    ec.to_span(nil).should(eq(""))
+  end
+
   it "0 resets all" do
     ec = Oho::ColorEscapeCode.new("[0m", default_options) #reset all the things
     prior_ec = Oho::ColorEscapeCode.new("[1;2;3;4;8;36;46m", default_options)

spec/oho/converter_spec.cr

@@ -35,7 +35,27 @@ describe Oho::Converter do
     test_string = "\033[36mfoo\033[Kbar\033[0m"
     response, escape_code = c.process(test_string, nil)
     response.should(eq("<span style=\"color: aqua; \">foobar</span>"))
+  end
+
+  it "ignores screen mode sequences" do
+    c = Oho::Converter.new(default_options)
+    test_string = "\033[=1;7hfoo\033[=0l"
+    response, escape_code = c.process(test_string, nil)
+    response.should(eq("foo"))
+  end
+
+  it "really ignores screen mode sequences" do
+    c = Oho::Converter.new(default_options)
+    test_string="\033[?1h\033=\r\033[33mcommit abcd\r\033[K\033[?1l\033>"
+    response, escape_code = c.process(test_string, nil)
+    response.should(eq("\r<span style=\"color: yellow; \">commit abcd\r"))
+  end
 
+  it "ignores question mark screen mode sequences" do
+    c = Oho::Converter.new(default_options)
+    test_string = "\033[?7hfoo\033[?7l"
+    response, escape_code = c.process(test_string, nil)
+    response.should(eq("foo"))
   end
 
   it "removes empty spans that do nothing" do
@@ -44,6 +64,7 @@ describe Oho::Converter do
     response, escape_code = c.process(test_string, nil)
     response.should(eq("foo"))
   end
+
   it "removes spans that encapsulate nothing" do
     c = Oho::Converter.new(default_options)
     test_string = "\033[0mfoo\033[0m"

src/oho/color_escape_code.cr

@@ -373,18 +373,26 @@ module Oho
     getter background_color
     getter styles : Array(Int32)
     getter string
+    getter ignorable
 
     @foreground_color : String?
     @background_color : String?
     @styles           : Array(Int32)
+    @ignorable        : Bool
 
     def initialize(@string : String, @options : Hash(Symbol, String))
-      if @string.size < 3 || @string[0] != '[' || @string[-1] != 'm'
-        if @string != "[m"
-          raise InvalidEscapeCode.new("Invalid escape code: #{@string.split("").inspect}")
-        else
+      @ignorable = false
+      if @string.size < 3 || @string[0] != '[' || @string[-1] != 'm' || @string[1] == '?'
+        if @string == "[m"
           # really? was it so hard to write a damn zero?
           @string = "[0m"
+        elsif @string[1] == '?' || is_screen_mode?(@string)
+          #argh. ? marks it as "private use"
+          #      (a category set aside for implementation-specific features in the standard)
+          #      "screen mode" sequences are not supported.
+          @ignorable = true
+        else
+          raise InvalidEscapeCode.new("Invalid escape code: #{@string.split("").inspect}")
         end
       end
       # if the string has a zero code in it that isn't part of
@@ -405,21 +413,27 @@ module Oho
       #   end
       # end
       # hell_regexp=".*(?<![34]8;5#{rgb})[;\[](0[;m])"
-      hell_regexp=".*(?<![34]8;5|[34]8;2;\\d|[34]8;2;\\d;\\d|[34]8;2;\\d;\\d;\\d|[34]8;2;\\d;\\d;\\d\\d|[34]8;2;\\d;\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d|[34]8;2;\\d;\\d\\d;\\d|[34]8;2;\\d;\\d\\d;\\d\\d|[34]8;2;\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d\\d;\\d|[34]8;2;\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d|[34]8;2;\\d\\d;\\d|[34]8;2;\\d\\d;\\d;\\d|[34]8;2;\\d\\d;\\d;\\d\\d|[34]8;2;\\d\\d;\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d;\\d|[34]8;2;\\d\\d;\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d;\\d|[34]8;2;\\d\\d\\d;\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d\\d\\d)[;[](0[;m])"
-      cleansed_string = @string.sub( /#{hell_regexp}/, "\\1")
-      @styles = extract_styling(cleansed_string)
-      @background_color = extract_background_color(cleansed_string)
-      if @background_color == "USE_DEFAULT"
-        @background_color = @options.fetch(:background_color, "initial")
-      end
-      @foreground_color = extract_foreground_color(cleansed_string)
-      if @foreground_color == "USE_DEFAULT"
-        @foreground_color = @options.fetch(:foreground_color, "initial")
+      if ! @ignorable
+        hell_regexp=".*(?<![34]8;5|[34]8;2;\\d|[34]8;2;\\d;\\d|[34]8;2;\\d;\\d;\\d|[34]8;2;\\d;\\d;\\d\\d|[34]8;2;\\d;\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d|[34]8;2;\\d;\\d\\d;\\d|[34]8;2;\\d;\\d\\d;\\d\\d|[34]8;2;\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d\\d|[34]8;2;\\d;\\d\\d\\d;\\d|[34]8;2;\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d|[34]8;2;\\d\\d;\\d|[34]8;2;\\d\\d;\\d;\\d|[34]8;2;\\d\\d;\\d;\\d\\d|[34]8;2;\\d\\d;\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d;\\d|[34]8;2;\\d\\d;\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d;\\d|[34]8;2;\\d\\d\\d;\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d\\d|[34]8;2;\\d\\d\\d;\\d\\d\\d;\\d\\d\\d)[;[](0[;m])"
+        cleansed_string = @string.sub( /#{hell_regexp}/, "\\1")
+        @styles = extract_styling(cleansed_string)
+        @background_color = extract_background_color(cleansed_string)
+        if @background_color == "USE_DEFAULT"
+          @background_color = @options.fetch(:background_color, "initial")
+        end
+        @foreground_color = extract_foreground_color(cleansed_string)
+        if @foreground_color == "USE_DEFAULT"
+          @foreground_color = @options.fetch(:foreground_color, "initial")
+        end
+      else # @ignorable == true
+        @foreground_color="USE_DEFAULT"
+        @background_color="USE_DEFAULT"
+        @styles=extract_styling("")
       end
     end
 
     def affects_display?() : Bool
-      true
+      @ignorable ? false : true
     end
     # we take in the prior escape_code
     # in part to know we have to end the prior code
@@ -430,6 +444,7 @@ module Oho
     # give the headaches to the  browser and anyone
     # reading the source. Headaches are bad.
     def to_span(escape_code : EscapeCode?) : String
+      return "" if @ignorable
       span = String.build do |str|
         if ! escape_code.nil? && escape_code.as(EscapeCode).affects_display?
           str << "</span>"
@@ -470,6 +485,38 @@ module Oho
     def raw : String
       @string
     end
+
+    # Screen Modes
+    # Documented for future work, but not directly supported.
+    # ESC[=#;7h or
+    # ESC[=h or
+    # ESC[=0h or
+    # ESC[?7h
+    # put screen in indicated mode where # is:
+    # 0 	40 x 25 black & white
+    # 1 	40 x 25 color
+    # 2 	80 x 25 b&w
+    # 3 	80 x 25 color
+    # 4 	320 x 200 color graphics
+    # 5 	320 x 200 b & w graphics
+    # 6 	640 x 200 b & w graphics
+    # 7 	to wrap at end of line
+    # RESETTING....
+    # ESC[=#;7l or
+    # ESC[=l or
+    # ESC[=0l or
+    # ESC[?7l
+    # resets mode # set with above command
+    private def is_screen_mode?(sequence : String ) : Bool
+
+      # they start with [=Xh or [?7h
+      # they end with [=xl or [?7l
+      # start screen mode
+      return true if /^\[=\d?(?:h|l)$/ =~ @string
+      return true if /^\[?7(?:h|l)/    =~ @string
+      return true if /^\[=\d;7(?:h|l)/ =~ @string
+      false
+    end
     private def generate_foreground_string(escape_code : EscapeCode?) : String
       if ! foreground_color.nil? && foreground_color != ""
          return "color: #{foreground_color}; "