Excubo.WebCompiler

Excubo.WebCompiler is a dotnet global tool that compiles Scss files, minimizes css / js assets, and gzips files.

This project is based on madskristensen/WebCompiler. However, the dependency to node and the node modules have been removed, to facilitate a pure dotnet core implementation. As a benefit, this implementation is cross-platform (x64 linux/win are tested, please help by testing other platforms!).

⚠️ A common mistake is to add the package Excubo.WebCompiler as a nuget package reference to a project (e.g. by installing it via the nuget package manager in Visual Studio). This does not work! Instead, one needs to install it as a dotnet tool. See the "Getting started" section further down on this page.

Features

• Compilation of Scss files
• Dedicated compiler options for each individual file
• Detailed error messages
• dotnet core build pipeline support cross-platform
• Minify the compiled output
• Minification options for each language is customizable
• Autoprefix for CSS

Changelog

Changes in version 4.0.1

Drop of support for net6.0. Add support for net9.0.

Changes in version 4.X.Y

The default value for zipping minified assets has changed from true to false. This has no effect to pre-existing configuration files. The change was made in anticipation of a new feature in the net9.0 SDK.

Changes in version 3.8.14

Support for net7.0 was dropped. The nupkg file was getting outrageously large due to dependencies and duplication across the target frameworks.

Changes in version 3.3.Y

Breaking Change / Warning: This change removes the key of IgnoreFolders and IgnoreFiles per 3.2.Y and in favour of an "Ignore" key with support for File Globbing support.

If no Ignore value is defined in the CompilerSettings.json then **/_. (files prefixed with _) will be ignored. If you wish to continue this behaviour and also ignore other patterns, ensure to also include this pattern.

Simply add the following to CompilerSettings.json:

  "CompilerSettings": {
     "Ignore": [ "**/_*.*", "wwwroot/*.scss", "wwwroot/css/specific-file.scss", "wwwroot/_lib/**/*.scss", "bin/**/*", "obj/**/*" ],
  }

Changes in version 3.2.Y

Supports excluding certain files and folders (nb. Sub folders must be specified specifically if wanting to be ignored) when using recursive mode Simply add the following to CompilerSettings.json:

  "CompilerSettings": {
     "IgnoreFolders": ["./wwwroot/", "./bin/", "./obj/", "./wwwroot/sass/"],
     "IgnoreFiles": ["./sass/_variables.scss"]
  }

Changes in version 3.1.Y

Support for netcoreapp3.1 and net5.0 were dropped. The nupkg file was getting outrageously large due to dependencies and duplication across the target frameworks.

Changes in version 3.X.Y

The underlying SASS compiler is changed from libsass to dart-sass. This is a necessary change, as libsass is discontinued. There are two breaking changes when working with the config json file:

• CompilerSettings.Sass.OutputStyle: The valid values are now Expanded or Compressed. The former default value of Nested is now invalid.
• The property CompilerSettings.Sass.Precision does not exist anymore.

  "CompilerSettings": {
    "Sass": {
      "IndentType": "Space",
      "IndentWidth": 2,
      "OutputStyle": "Expanded", // was: "Nested"
      //"Precision": 5, // Remove this
      "RelativeUrls": true,
      "LineFeed": "Lf",
      "SourceMap": false
    }
  }

Changes in version 2.4.X

Added support for .NET 5. You will most likely only notice that when using webcompiler in a docker context, but that's covered now as well!

Changes in version 2.3.X

There are now two more options:

• -o/--output-dir helps to put files into a different folder. See webcompiler -o --help for more details.
• -p/--preserve disable makes all temporary files disappear (note that this can increase compile time. The default is to keep all temporary files).

Changes in version 2.1.X

• Previously, running e.g. webcompiler -r without specifying a file and/or folder just returned without any message, warning or error. This is now an error. If the intention is to run in the working directory, use webcompiler -r ..
• Now writes to stderr instead of stdout where appropriate.
• Bug fixed: Sass files were not recompiled on change, if that change was to the sass file itself rather than one of its dependencies. Now it correctly recompiles for any change to the file itself or any of its dependencies.

Breaking changes in version 2.0.X

The command line interface has been rewritten from scratch to enable sensible defaults without the need to have a configuration file around. Starting with version 2.0.0, the old compilerconfig.json.defaults is incompatible. A new file can be created with webcompiler --defaults (optional).

Usage:
  webcompiler file1 file2 ... [options]
  webcompiler [options]

Options:
  -c|--config <conf.json>          Specify a configuration file for compilation.
  -d|--defaults [conf.json]        Write a default configuration file (file name is webcompilerconfiguration.json, if none is specified).
  -f|--files <files.conf>          Specify a list of files that should be compiled.
  -h|--help                        Show command line help.
  -m|--minify [disable/enable]     Enable/disable minification (default: enabled), ignored if configuration file is provided.
  -o|--output-dir <path/to/dir>    Specify the output directory, ignored if configuration file is provided.
  -p|--preserve [disable/enable]   Enable/disable whether to preserve intermediate files (default: enabled).
  -r|--recursive                   Recursively search folders for compilable files (only if any of the provided arguments is a folder).
  -z|--zip [disable/enable]        Enable/disable gzip (default: enabled), ignored if configuration file is provided.
  -a|--autoprefix [disable/enable] Enable/disable autoprefixing (default: enabled), ignored if configuration file is provided.

Recommended default usage: webcompiler -r wwwroot.

Language support

Due to the removal of node as a dependency (as opposed to madskristensen/WebCompiler), support for languages other than Scss is not yet available. Please get in touch if you want to contribute to any of the following languages, or if you want to add yet another language.

• LESS
• Stylus
• JSX
• ES6
• (Iced)CoffeeScript

Getting started

Global

1. Install the tool as dotnet global tool

Excubo.Webcompiler is distributed as a nuget package. You can install it in a command line using

dotnet tool install Excubo.WebCompiler --global

2. Call webcompiler

webcompiler -r wwwroot

Local

It's also possible to use Excubo.Webcompiler as a local tool (ideal for CI environments)

1. Create a new tool manifest

dotnet new tool-manifest

2. Add Excubo.Webcompiler

dotnet tool install Excubo.WebCompiler

3. Restore

dotnet tool restore

4. Usage

dotnet tool webcompiler -h

Build integrations

Command line / terminal

Global

You can simply call webcompiler with the appropriate options, e.g.

webcompiler -r wwwroot

Local

dotnet run tool webcompiler -r wwwroot

or you can simply call:

dotnet webcompiler -r wwwroot

MSBuild

You can add webcompiler as a Target in your csproj file. This works cross platform:

  <Target Name="CompileStaticAssets" AfterTargets="AfterBuild">
    <Exec Command="webcompiler -r wwwroot" StandardOutputImportance="high" />
  </Target>

In this example, webcompiler is executed on the folder wwwroot inside your project folder.

Docker

The integration into docker images is as straight-forward as installing the tool and invoking it. However, there's a caveat that some users ran into, which is the use of alpine-based images, such as mcr.microsoft.com/dotnet/sdk:5.0-alpine. Excubo.WebCompiler will not work on this image, as some fundamental libraries are missing on alpine. The alpine distribution is usually intended to create small resulting images. If this is the goal, the best approach is to perform build/compilation operations in a non-alpine distribution, and then finally copy only the resulting files to an alpine based image intended only for execution. Learn more about it here, in Microsoft's usage for dotnet and here, in the docker documentation about multi-stage-build.

MSBuild with execution of webcompiler only if it is installed

Global

This configuration will not break the build if Excubo.WebCompiler is not installed. This can be helpful, e.g. if compilation is only necessary on the build server. It will also check to see if you're executing inside a Microsoft.NET.Sdk.Razor project, and shut off compression accordingly.

<Target Name="CompileStaticAssets" AfterTargets="CoreCompile" >
    <PropertyGroup>
        <!-- Compression should be disabled by default if we're in a Razor Class Library -->
        <WebCompilerCompression Condition="'$(RazorLangVersion)' != ''">disabled</WebCompilerCompression>
        <WebCompilerCompression Condition="'$(RazorLangVersion)' == ''">enabled</WebCompilerCompression>
    </PropertyGroup>

    <!-- Test if WebCompiler is installed -->
    <Exec Command="webcompiler -h" ContinueOnError="true" StandardOutputImportance="low" StandardErrorImportance="low" LogStandardErrorAsError="false" IgnoreExitCode="true">
        <Output TaskParameter="ExitCode" PropertyName="ErrorCode" />
    </Exec>

    <!-- Execute the WebCompiler task if the test was successful -->
    <Exec Command="webcompiler -r wwwroot --zip ${WebCompilerCompression}" StandardOutputImportance="high" StandardErrorImportance="high" Condition="'$(ErrorCode)' == '0'" />
</Target>

The PropertyGroup tests for Razor. The first Exec command simply tests whether Excubo.WebCompiler is installed at all. The second Exec command then executes webcompiler recursively on the wwwroot folder if it is installed, and using compression if we're NOT in a Razor Class Library or Blazor project.

Local

Using dotnet tool locally is quite simple. Unfortunately, there's no easy way to check if tools already exists (as the help always returns error code 0) without a script.

  <Target Name="ToolRestore" BeforeTargets="PreBuildEvent">
      <Exec Command="dotnet tool restore" StandardOutputImportance="high" />
  </Target>

  <Target Name="PreBuild" AfterTargets="ToolRestore">
      <Exec Command="dotnet tool run webcompiler -r wwwroot" StandardOutputImportance="high" />
  </Target>

If you only rely on webcompiler, it may be preferable to use the below PreBuildEvent

 <Target Name="ToolRestore" BeforeTargets="PreBuildEvent">
        <Exec Command="dotnet tool update excubo.webcompiler" StandardOutputImportance="high" />
    </Target>

Which will either:

• Do nothing if latest is installed
• Install the latest if either out of date or uninstalled

Compile on save (dotnet watch)

For automatic compilation whenever the content of source files change, add the following to your csproj:

<ItemGroup>
    <!--specify file extensions here as needed-->
    <Watch Include="**\*.scss" />
</ItemGroup>

Using net8.0 or newer

dotnet watch no longer supports running tools, see https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-watch#arguments. As a workaround (see #95), integrate the MSBuild target CompileStaticAssets above, then run dotnet watch build -t:CompileStaticAssets --no-restore.

Using net7.0 or older

Run dotnet watch tool run webcompiler with the appropriate options in a terminal, e.g. dotnet watch tool run webcompiler -r wwwroot.

Configuration

If you want to change aspects of the compilation and minification process, create a configuration file, modify it to your needs, and run webcompiler using this config file:

1. create config file (default file name: webcompilerconfiguration.json)

webcompiler --defaults

The default configuration is

{
  "Minifiers": {
    "GZip": true,
    "Enabled": true,
    "Css": {
      "CommentMode": "Important",
      "ColorNames": "Hex",
      "TermSemicolons": true,
      "OutputMode": "SingleLine",
      "IndentSize": 2
    },
    "Javascript": {
      "RenameLocals": true,
      "PreserveImportantComments": true,
      "EvalTreatment": "Ignore",
      "TermSemicolons": true,
      "OutputMode": "SingleLine",
      "IndentSize": 2
    }
  },
  "Autoprefix": {
    "Enabled": true,
    "ProcessingOptions": {
      "Browsers": [
        "last 4 versions"
      ],
      "Cascade": true,
      "Add": true,
      "Remove": true,
      "Supports": true,
      "Flexbox": "All",
      "Grid": "None",
      "IgnoreUnknownVersions": false,
      "Stats": "",
      "SourceMap": true,
      "InlineSourceMap": false,
      "SourceMapIncludeContents": false,
      "OmitSourceMapUrl": false
    }
  },
  "CompilerSettings": {
    "Sass": {
      "IndentType": "Space",
      "IndentWidth": 2,
      "OutputStyle": "Expanded",
      "RelativeUrls": true,
      "LineFeed": "Lf",
      "SourceMap": false
    }
  },
  "Output": {
    "Preserve": true
  }
}

2. change config file

Change anything in the generated config file according to your needs. If you need help with the available settings, please refer to the documentation of DartSassHost, NUglify and AutoprefixerHost.

Some WebCompiler-specific configurations are:

• "Output": { "Preserve": true }
  When disabled, removes all temporary files (which could increase compile time; the default is to keep all temporary files). Equivalent to the CLI's -p and --preserve switches.

• "Output": { "Directory": "your/path/prefix/here" }
  Specifies the output directory. Equivalent to the CLI's -o and --output-dir switches. See webcompiler -o --help for more details.

3. Make webcompiler use these options

webcompiler -r wwwroot -c webcompilerconfiguration.json

Error list

When a compiler error occurs, the tool exits with code 1 and displays the error to the console.

Contributing

This project is just starting. You can help in many different ways:

• File bug reports

  If you find a bug with the tool itself, please file a bug. If the result of compilation is incorrect, please file a bug with the respective library (see the list of libraries), and only file a bug report here, if the version used is outdated.

• Implement support for a language

  Please submit your pull request for the language that you're implementing. Please make sure that your code is tested.

• Ask for support of a specific language

  If you would like to see support of a specific language, but can't implement it yourself, please search the issues for the language and leave your +1 vote on the issue, or file a new issue with the name of the language.

Libraries

Excubo.WebCompiler depends on nuget packages for the compilation tasks:

Language	Library	Comments
Sass	LibSassHost
Sass	DartSassHost	WebCompiler 3.X.Y+
Autoprefix	AutoprefixHost
CSS/JS	NUglify