Apply default theme for syntax highlighting (bridgetownrb#516)

* Apply default theme for syntax highlighting

This change adds a default theme for syntax highlighting so users
can see the full power of syntax highlighting when they create a
new bridgetown app.

The theme is stored in a new `syntax-higlighting.css` files.

* Use the same css file for both PostCSS & Sass

* fix tests

Co-authored-by: Jared White <[email protected]>

bridgetown-core/lib/bridgetown-core/commands/new.rb

@@ -116,6 +116,7 @@ def create_site(new_site_path)
         template("frontend/javascript/index.js.erb", "frontend/javascript/index.js")
         template("src/index.md.erb", "src/index.md")
         template("src/posts.md.erb", "src/posts.md")
+        copy_file("frontend/styles/syntax-highlighting.css")
 
         case options["templates"]
         when "erb"

bridgetown-core/lib/site_template/frontend/javascript/index.js.erb

@@ -3,6 +3,7 @@ import "index.css"
 <%- else -%>
 import "index.scss"
 <%- end -%>
+import "syntax-highlighting.css"
 
 // Import all JavaScript & CSS files from src/_components
 <%- if frontend_bundling_option == "esbuild" -%>

bridgetown-core/lib/site_template/frontend/styles/syntax-highlighting.css

@@ -0,0 +1,77 @@
+/* 
+  Syntax Highlighting for Code Snippets
+
+  https://www.bridgetownrb.com/docs/liquid/tags#stylesheets-for-syntax-highlighting
+
+  Other styles available eg. https://github.com/jwarby/jekyll-pygments-themes
+  To use another style, delete all styles in this file and replace them with
+  the new styles. Or create your own!
+
+*/
+
+pre.highlight {
+  padding: 16px;
+  background-color: #F6F8FA;
+}
+
+.highlight .hll { background-color: #ffffcc }
+.highlight .c { color: #999988; font-style: italic } /* Comment */
+.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
+.highlight .k { color: #000000; font-weight: bold } /* Keyword */
+.highlight .o { color: #000000; font-weight: bold } /* Operator */
+.highlight .cm { color: #999988; font-style: italic } /* Comment.Multiline */
+.highlight .cp { color: #999999; font-weight: bold; font-style: italic } /* Comment.Preproc */
+.highlight .c1 { color: #999988; font-style: italic } /* Comment.Single */
+.highlight .cs { color: #999999; font-weight: bold; font-style: italic } /* Comment.Special */
+.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
+.highlight .ge { color: #000000; font-style: italic } /* Generic.Emph */
+.highlight .gr { color: #aa0000 } /* Generic.Error */
+.highlight .gh { color: #999999 } /* Generic.Heading */
+.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
+.highlight .go { color: #888888 } /* Generic.Output */
+.highlight .gp { color: #555555 } /* Generic.Prompt */
+.highlight .gs { font-weight: bold } /* Generic.Strong */
+.highlight .gu { color: #aaaaaa } /* Generic.Subheading */
+.highlight .gt { color: #aa0000 } /* Generic.Traceback */
+.highlight .kc { color: #000000; font-weight: bold } /* Keyword.Constant */
+.highlight .kd { color: #000000; font-weight: bold } /* Keyword.Declaration */
+.highlight .kn { color: #000000; font-weight: bold } /* Keyword.Namespace */
+.highlight .kp { color: #000000; font-weight: bold } /* Keyword.Pseudo */
+.highlight .kr { color: #000000; font-weight: bold } /* Keyword.Reserved */
+.highlight .kt { color: #445588; font-weight: bold } /* Keyword.Type */
+.highlight .m { color: #009999 } /* Literal.Number */
+.highlight .s { color: #d01040 } /* Literal.String */
+.highlight .na { color: #008080 } /* Name.Attribute */
+.highlight .nb { color: #0086B3 } /* Name.Builtin */
+.highlight .nc { color: #445588; font-weight: bold } /* Name.Class */
+.highlight .no { color: #008080 } /* Name.Constant */
+.highlight .nd { color: #3c5d5d; font-weight: bold } /* Name.Decorator */
+.highlight .ni { color: #800080 } /* Name.Entity */
+.highlight .ne { color: #990000; font-weight: bold } /* Name.Exception */
+.highlight .nf { color: #990000; font-weight: bold } /* Name.Function */
+.highlight .nl { color: #990000; font-weight: bold } /* Name.Label */
+.highlight .nn { color: #555555 } /* Name.Namespace */
+.highlight .nt { color: #000080 } /* Name.Tag */
+.highlight .nv { color: #008080 } /* Name.Variable */
+.highlight .ow { color: #000000; font-weight: bold } /* Operator.Word */
+.highlight .w { color: #bbbbbb } /* Text.Whitespace */
+.highlight .mf { color: #009999 } /* Literal.Number.Float */
+.highlight .mh { color: #009999 } /* Literal.Number.Hex */
+.highlight .mi { color: #009999 } /* Literal.Number.Integer */
+.highlight .mo { color: #009999 } /* Literal.Number.Oct */
+.highlight .sb { color: #d01040 } /* Literal.String.Backtick */
+.highlight .sc { color: #d01040 } /* Literal.String.Char */
+.highlight .sd { color: #d01040 } /* Literal.String.Doc */
+.highlight .s2 { color: #d01040 } /* Literal.String.Double */
+.highlight .se { color: #d01040 } /* Literal.String.Escape */
+.highlight .sh { color: #d01040 } /* Literal.String.Heredoc */
+.highlight .si { color: #d01040 } /* Literal.String.Interpol */
+.highlight .sx { color: #d01040 } /* Literal.String.Other */
+.highlight .sr { color: #009926 } /* Literal.String.Regex */
+.highlight .s1 { color: #d01040 } /* Literal.String.Single */
+.highlight .ss { color: #990073 } /* Literal.String.Symbol */
+.highlight .bp { color: #999999 } /* Name.Builtin.Pseudo */
+.highlight .vc { color: #008080 } /* Name.Variable.Class */
+.highlight .vg { color: #008080 } /* Name.Variable.Global */
+.highlight .vi { color: #008080 } /* Name.Variable.Instance */
+.highlight .il { color: #009999 } /* Literal.Number.Integer.Long */

bridgetown-core/test/test_new_command.rb

@@ -27,6 +27,7 @@ def template_config_files
       "/Rakefile",
       "/package.json",
       "/frontend/javascript/index.js",
+      "/frontend/styles/syntax-highlighting.css",
       "/src/_layouts",
       "/src/_components",
       "/src/index.md",