Rendering fails with no errors

[obahareth]

I'm building a Base16 builder in Elixir and I've come across a case where rendering is failing with no errors. Here's my test case:

defmodule TestMustache do 
  def test_mustache() do
    data = %{
      "base04-rgb-b" => 109.0,
      "base07-rgb-g" => 23.0,
      "base00-dec-b" => 0.9568627450980393,
      "scheme-name" => "Atelier Cave Light",
      "base0C-rgb-r" => 57.0,
      "base00-dec-r" => 0.9372549019607843,
      "base0C-dec-g" => 0.5450980392156862,
      "base0B-rgb-r" => 42.0,
      "base04-rgb-r" => 101.0,
      "base04-hex-r" => "65",
      "base0B-hex" => "2a9292",
      "base0E-hex" => "955ae7",
      "base0E-dec-b" => 0.9058823529411765,
      "base0F-dec-b" => 0.7490196078431373,
      "base0D-hex-r" => "57",
      "base07-hex-b" => "1c",
      "base08-dec-g" => 0.27450980392156865,
      "base08-hex-r" => "be",
      "base05-rgb-b" => 96.0,
      "base0E-dec-g" => 0.35294117647058826,
      "base01-dec-r" => 0.8862745098039215,
      "base0F-rgb-r" => 191.0,
      "base09-hex-g" => "57",
      "base09-rgb-r" => 170.0,
      "base01-hex-r" => "e2",
      "base01-hex" => "e2dfe7",
      "base06-dec-r" => 0.14901960784313725,
      "base05-hex-r" => "58",
      "base05-dec-g" => 0.3215686274509804,
      "base01-rgb-b" => 231.0,
      "base0A-rgb-r" => 160.0,
      "base00-hex-g" => "ec",
      "base0C-hex-r" => "39",
      "base02-dec-r" => 0.5450980392156862,
      "base0C-dec-b" => 0.7764705882352941,
      "base07-dec-r" => 0.09803921568627451,
      "base04-dec-g" => 0.37254901960784315,
      "base0B-hex-g" => "92",
      "base00-rgb-g" => 236.0,
      "base07-hex-r" => "19",
      "base0D-rgb-g" => 109.0,
      "base07-hex-g" => "17",
      "base0C-hex-b" => "c6",
      "base09-rgb-b" => 60.0,
      "scheme-author" => "Bram de Haan (http://atelierbramdehaan.nl)",
      "base04-hex-b" => "6d",
      "base02-rgb-r" => 139.0,
      "base00-hex" => "efecf4",
      "base03-hex-r" => "7e",
      "base08-hex-b" => "78",
      "base03-hex-g" => "78",
      "base0A-rgb-b" => 59.0,
      "base06-rgb-b" => 42.0,
      "base0C-rgb-g" => 139.0,
      "base0B-dec-r" => 0.16470588235294117,
      "base04-rgb-g" => 95.0,
      "base0E-rgb-r" => 149.0,
      "base06-hex-b" => "2a",
      "base0D-rgb-r" => 87.0,
      "base0B-rgb-g" => 146.0,
      "base09-dec-b" => 0.23529411764705882,
      "base00-hex-r" => "ef",
      "base02-dec-g" => 0.5294117647058824,
      "base08-dec-r" => 0.7450980392156863,
      "base0A-hex-r" => "a0",
      "base09-hex" => "aa573c",
      "base06-dec-b" => 0.16470588235294117,
      "base07-hex" => "19171c",
      "base05-dec-r" => 0.34509803921568627,
      "base04-hex" => "655f6d",
      "base01-rgb-g" => 223.0,
      "base02-dec-b" => 0.5725490196078431,
      "base0A-hex" => "a06e3b",
      "base0F-rgb-b" => 191.0,
      "base07-dec-b" => 0.10980392156862745,
      "base06-rgb-g" => 35.0,
      "base08-rgb-g" => 70.0,
      "base07-rgb-b" => 28.0,
      "base0F-dec-g" => 0.25098039215686274,
      "base05-dec-b" => 0.3764705882352941,
      "base0C-dec-r" => 0.2235294117647059,
      "base02-hex" => "8b8792",
      "base0A-dec-b" => 0.23137254901960785,
      "base0E-rgb-g" => 90.0,
      "base02-hex-b" => "92",
      "base06-hex-g" => "23",
      "base0F-rgb-g" => 64.0,
      "base06-hex" => "26232a",
      "base0C-rgb-b" => 198.0,
      "base04-dec-b" => 0.42745098039215684,
      "base0A-rgb-g" => 110.0,
      "base05-hex-g" => "52",
      "base01-dec-b" => 0.9058823529411765,
      "base0B-rgb-b" => 146.0,
      "base07-dec-g" => 0.09019607843137255,
      "base01-hex-b" => "e7",
      "base00-hex-b" => "f4",
      "base03-hex" => "7e7887",
      "base0E-hex-b" => "e7",
      "base05-hex-b" => "60",
      "base03-rgb-b" => 135.0,
      "base0A-hex-b" => "3b",
      "base02-hex-r" => "8b",
      "base03-hex-b" => "87",
      "base02-rgb-b" => 146.0,
      "base07-rgb-r" => 25.0,
      "base0F-hex-r" => "bf",
      "base01-rgb-r" => 226.0,
      "base03-rgb-g" => 120.0,
      "base02-rgb-g" => 135.0,
      "base0F-hex-g" => "40",
      "base0E-hex-g" => "5a",
      "base0B-hex-r" => "2a",
      "base06-hex-r" => "26",
      "base04-hex-g" => "5f",
      "base0A-hex-g" => "6e",
      "base09-dec-g" => 0.3411764705882353,
      "base08-hex-g" => "46",
      "base09-hex-r" => "aa",
      "base0F-hex" => "bf40bf",
      "base03-dec-b" => 0.5294117647058824,
      "base09-rgb-g" => 87.0,
      "base0C-hex" => "398bc6",
      "base0E-hex-r" => "95",
      "base0D-hex-b" => "db",
      "base06-rgb-r" => 38.0,
      "base0E-rgb-b" => 231.0,
      "base0A-dec-r" => 0.6274509803921569,
      "base01-dec-g" => 0.8745098039215686,
      "base06-dec-g" => 0.13725490196078433,
      "base0E-dec-r" => 0.5843137254901961,
      "base09-dec-r" => 0.6666666666666666,
      "base05-rgb-g" => 82.0,
      "base0B-dec-g" => 0.5725490196078431,
      "base03-dec-r" => 0.49411764705882355,
      "base05-rgb-r" => 88.0,
      "base0A-dec-g" => 0.43137254901960786,
      "base00-rgb-b" => 244.0,
      "base0F-hex-b" => "bf",
      "base0B-hex-b" => "92",
      "base08-rgb-b" => 120.0,
      "base08-rgb-r" => 190.0,
      "base0C-hex-g" => "8b",
      "base0D-rgb-b" => 219.0,
      "base08-dec-b" => 0.47058823529411764,
      "scheme-slug" => "atelier-cave-light",
      "base05-hex" => "585260",
      "base02-hex-g" => "87",
      "base01-hex-g" => "df",
      "base03-dec-g" => 0.47058823529411764,
      "base0D-hex" => "576ddb",
      "base0F-dec-r" => 0.7490196078431373,
      "base04-dec-r" => 0.396078431372549,
      "base0D-dec-g" => 0.42745098039215684,
      "base00-rgb-r" => 239.0,
      "base0B-dec-b" => 0.5725490196078431,
      "base0D-hex-g" => "6d",
      "base00-dec-g" => 0.9254901960784314,
      "base09-hex-b" => "3c",
      "base03-rgb-r" => 126.0,
      "base0D-dec-r" => 0.3411764705882353,
      "base08-hex" => "be4678",
      "base0D-dec-b" => 0.8588235294117647
    }

    template = """
    # Base16 {{scheme-name}} - alacritty color config
    # {{scheme-author}}
    colors:
      # Default colors
      primary:
        background: '0x{{base00-hex}}'
        foreground: '0x{{base05-hex}}'

      # Colors the cursor will use if `custom_cursor_colors` is true
      cursor:
        text: '0x{{base00-hex}}'
        cursor: '0x{{base05-hex}}'

      # Normal colors
      normal:
        black:   '0x{{base00-hex}}'
        red:     '0x{{base08-hex}}'
        green:   '0x{{base0B-hex}}'
        yellow:  '0x{{base0A-hex}}'
        blue:    '0x{{base0D-hex}}'
        magenta: '0x{{base0E-hex}}'
        cyan:    '0x{{base0C-hex}}'
        white:   '0x{{base05-hex}}'

      # Bright colors
      bright:
        black:   '0x{{base03-hex}}'
        red:     '0x{{base09-hex}}'
        green:   '0x{{base01-hex}}'
        yellow:  '0x{{base02-hex}}'
        blue:    '0x{{base04-hex}}'
        magenta: '0x{{base06-hex}}'
        cyan:    '0x{{base0F-hex}}'
        white:   '0x{{base05-hex}}'

    """
    Mustache.render(template, data)
  end
end

and the output is not interpolated and look like this:

"# Base16 {{scheme-name}} - alacritty color config\n# {{scheme-author}}\ncolors:\n  # Default colors\n  primary:\n    background: '0x{{base00-hex}}'\n    foreground: '0x{{base05-hex}}'\n\n  # Colors the cursor will use if `custom_cursor_colors` is true\n  cursor:\n    text: '0x{{base00-hex}}'\n    cursor: '0x{{base05-hex}}'\n\n  # Normal colors\n  normal:\n    black:   '0x{{base00-hex}}'\n    red:     '0x{{base08-hex}}'\n    green:   '0x{{base0B-hex}}'\n    yellow:  '0x{{base0A-hex}}'\n    blue:    '0x{{base0D-hex}}'\n    magenta: '0x{{base0E-hex}}'\n    cyan:    '0x{{base0C-hex}}'\n    white:   '0x{{base05-hex}}'\n\n  # Bright colors\n  bright:\n    black:   '0x{{base03-hex}}'\n    red:     '0x{{base09-hex}}'\n    green:   '0x{{base01-hex}}'\n    yellow:  '0x{{base02-hex}}'\n    blue:    '0x{{base04-hex}}'\n    magenta: '0x{{base06-hex}}'\n    cyan:    '0x{{base0F-hex}}'\n    white:   '0x{{base05-hex}}'\n\n"

(I'm on version 0.3.1 this time)

[space-pope]

I know this is about a month late, but it's failing because - is an invalid character for a variable in this Mustache library. I can't find any indication of valid/invalid characters in the original Mustache spec, but for Elixir it makes sense to forbid this character since it's forbidden in (unquoted) atoms. If you replace all the -s with _, rendering works.

[obahareth]

I actually switched to bbmustache (an Erlang library) and stopped having issues. I don’t really know much about the original Mustache spec, but bbmustache worked for me.