feat(ci): run Fornax to build docs

Author: xperiandri

build/Fornax.fs

@@ -0,0 +1,139 @@
+namespace Fake.DotNet
+
+open System.IO
+open Fake.Core
+open Fake.IO
+open Fake.IO.FileSystemOperators
+
+/// <summary>
+/// Contains tasks to interact with <a href="https://github.com/ionide/Fornax">Fornax</a> static site generator
+/// for F# documentation generation.
+/// </summary>
+[<RequireQualifiedAccess>]
+module Fornax =
+
+    /// <summary>
+    /// Fornax build command parameters and options
+    /// </summary>
+    type BuildParams = {
+        /// Working directory to run Fornax from (default: docs directory)
+        WorkingDirectory : string option
+
+        /// Timeout for the build process
+        Timeout : System.TimeSpan option
+
+        /// Whether to fail if Fornax returns non-zero exit code
+        FailOnError : bool
+    } with
+        /// Parameter default values.
+        static member Default = {
+            WorkingDirectory = None
+            Timeout = None
+            FailOnError = true
+        }
+
+    /// <summary>
+    /// Fornax watch command parameters and options
+    /// </summary>
+    type WatchParams = {
+        /// Working directory to run Fornax from (default: docs directory)
+        WorkingDirectory : string option
+
+        /// Port to serve content on (default: 8080)
+        Port : int option
+
+        /// Whether to fail if Fornax returns non-zero exit code
+        FailOnError : bool
+    } with
+        /// Parameter default values.
+        static member Default = {
+            WorkingDirectory = None
+            Port = None
+            FailOnError = true
+        }
+
+    /// <summary>
+    /// Build documentation using Fornax
+    /// </summary>
+    ///
+    /// <param name="setBuildParams">Function used to overwrite the build command default parameters.</param>
+    ///
+    /// <example>
+    /// <code lang="fsharp">
+    /// Fornax.build (fun p -> { p with WorkingDirectory = Some "./docs" })
+    /// </code>
+    /// </example>
+    let build setBuildParams =
+        let buildParams = setBuildParams BuildParams.Default
+
+        let processArgs =
+            CreateProcess.fromRawCommandLine "dotnet" "fornax build"
+            |> CreateProcess.withTimeout (buildParams.Timeout |> Option.defaultValue (System.TimeSpan.FromMinutes 10.0))
+            |> (fun args ->
+                match buildParams.WorkingDirectory with
+                | Some dir -> CreateProcess.withWorkingDirectory dir args
+                | None -> args)
+            |> (fun args ->
+                if buildParams.FailOnError then
+                    CreateProcess.ensureExitCode args
+                else
+                    args)
+
+        let result = processArgs |> Proc.run
+
+        if buildParams.FailOnError && result.ExitCode <> 0 then
+            failwithf "Fornax build failed with exit code %d" result.ExitCode
+        else
+            result
+
+    /// <summary>
+    /// Watch documentation using Fornax with hot reload
+    /// </summary>
+    ///
+    /// <param name="setWatchParams">Function used to overwrite the watch command default parameters.</param>
+    ///
+    /// <example>
+    /// <code lang="fsharp">
+    /// Fornax.watch (fun p -> { p with Port = Some 3000; WorkingDirectory = Some "./docs" })
+    /// </code>
+    /// </example>
+    let watch setWatchParams =
+        let watchParams = setWatchParams WatchParams.Default
+
+        let args =
+            match watchParams.Port with
+            | Some port -> $"fornax watch --port {port}"
+            | None -> "fornax watch"
+
+        let processArgs =
+            CreateProcess.fromRawCommandLine "dotnet" args
+            |> (fun args ->
+                match watchParams.WorkingDirectory with
+                | Some dir -> CreateProcess.withWorkingDirectory dir args
+                | None -> args)
+            |> (fun args ->
+                if watchParams.FailOnError then
+                    CreateProcess.ensureExitCode args
+                else
+                    args)
+
+        let result = processArgs |> Proc.run
+
+        if watchParams.FailOnError && result.ExitCode <> 0 then
+            failwithf "Fornax watch failed with exit code %d" result.ExitCode
+        else
+            result
+
+    /// <summary>
+    /// Clean Fornax cache and generated files
+    /// </summary>
+    ///
+    /// <param name="workingDirectory">Working directory where Fornax cache should be cleaned</param>
+    let cleanCache workingDirectory =
+        let cacheDir = workingDirectory </> "_public"
+        let tempDir = workingDirectory </> "_temp"
+
+        if Directory.Exists cacheDir then
+            Shell.cleanDir cacheDir
+        if Directory.Exists tempDir then
+            Shell.cleanDir tempDir