Add warnings when a codeblock tries to use an unsupported language

src/Elastic.Markdown/Myst/CodeBlocks/EnhancedCodeBlockParser.cs

@@ -84,11 +84,11 @@ public override bool Close(BlockProcessor processor, Block block)
 			"console" => "json",
 			"console-response" => "json",
 			"console-result" => "json",
-			"sh" => "bash",
-			"yml" => "yaml",
 			"terminal" => "bash",
 			_ => codeBlock.Language
 		};
+		if (!string.IsNullOrEmpty(codeBlock.Language) && !CodeBlock.Languages.Contains(codeBlock.Language))
+			codeBlock.EmitWarning($"Unknown language: {codeBlock.Language}");
 
 		var lines = codeBlock.Lines;
 		var callOutIndex = 0;

src/Elastic.Markdown/Myst/CodeBlocks/SupportedLanguages.cs

@@ -0,0 +1,193 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+namespace Elastic.Markdown.Myst.CodeBlocks;
+
+public static class CodeBlock
+{
+	private static readonly IReadOnlyDictionary<string, string> LanguageMapping = new Dictionary<string, string>
+	{
+		{ "1c", "" }, // 1C
+		{ "abnf", "" }, // ABNF
+		{ "accesslog", "" }, // Access logs
+		{ "ada", "" }, // Ada
+		{ "arduino", "ino" }, // Arduino (C++ w/Arduino libs)
+		{ "armasm", "arm" }, // ARM assembler
+		{ "avrasm", "" }, // AVR assembler
+		{ "actionscript", "as" }, // ActionScript
+		{ "angelscript", "asc" }, // AngelScript
+		{ "apache", "apacheconf" }, // Apache
+		{ "applescript", "osascript" }, // AppleScript
+		{ "arcade", "" }, // Arcade
+		{ "asciidoc", "adoc" }, // AsciiDoc
+		{ "aspectj", "" }, // AspectJ
+		{ "autohotkey", "" }, // AutoHotkey
+		{ "autoit", "" }, // AutoIt
+		{ "awk", "mawk, nawk, gawk" }, // Awk
+		{ "bash", "sh, zsh" }, // Bash
+		{ "basic", "" }, // Basic
+		{ "bnf", "" }, // BNF
+		{ "brainfuck", "bf" }, // Brainfuck
+		{ "csharp", "cs" }, // C#
+		{ "c", "h" }, // C
+		{ "cpp", "hpp, cc, hh, c++, h++, cxx, hxx" }, // C++
+		{ "cal", "" }, // C/AL
+		{ "cos", "cls" }, // Cache Object Script
+		{ "cmake", "cmake.in" }, // CMake
+		{ "coq", "" }, // Coq
+		{ "csp", "" }, // CSP
+		{ "css", "" }, // CSS
+		{ "capnproto", "capnp" }, // Cap’n Proto
+		{ "clojure", "clj" }, // Clojure
+		{ "coffeescript", "coffee, cson, iced" }, // CoffeeScript
+		{ "crmsh", "crm, pcmk" }, // Crmsh
+		{ "crystal", "cr" }, // Crystal
+		{ "d", "" }, // D
+		{ "dart", "" }, // Dart
+		{ "dpr", "dfm, pas, pascal" }, // Delphi
+		{ "diff", "patch" }, // Diff
+		{ "django", "jinja" }, // Django
+		{ "dns", "zone, bind" }, // DNS Zone file
+		{ "dockerfile", "docker" }, // Dockerfile
+		{ "dos", "bat, cmd" }, // DOS
+		{ "dsconfig", "" }, // dsconfig
+		{ "dts", "" }, // DTS (Device Tree)
+		{ "dust", "dst" }, // Dust
+		{ "ebnf", "" }, // EBNF
+		{ "elixir", "" }, // Elixir
+		{ "elm", "" }, // Elm
+		{ "erlang", "erl" }, // Erlang
+		{ "excel", "xls, xlsx" }, // Excel
+		{ "fsharp", "fs, fsx, fsi, fsscript" }, // F#
+		{ "fix", "" }, // FIX
+		{ "fortran", "f90, f95" }, // Fortran
+		{ "gcode", "nc" }, // G-Code
+		{ "gams", "gms" }, // Gams
+		{ "gauss", "gss" }, // GAUSS
+		{ "gherkin", "" }, // Gherkin
+		{ "go", "golang" }, // Go
+		{ "golo", "gololang" }, // Golo
+		{ "gradle", "" }, // Gradle
+		{ "graphql", "gql" }, // GraphQL
+		{ "groovy", "" }, // Groovy
+		{ "xml", "html, xhtml, rss, atom, xjb, xsd, xsl, plist, svg" }, // HTML, XML
+		{ "http", "https" }, // HTTP
+		{ "haml", "" }, // Haml
+		{ "handlebars", "hbs, html.hbs, html.handlebars" }, // Handlebars
+		{ "haskell", "hs" }, // Haskell
+		{ "haxe", "hx" }, // Haxe
+		{ "hy", "hylang" }, // Hy
+		{ "ini", "toml" }, // Ini, TOML
+		{ "inform7", "i7" }, // Inform7
+		{ "irpf90", "" }, // IRPF90
+		{ "json", "jsonc" }, // JSON
+		{ "java", "jsp" }, // Java
+		{ "javascript", "js, jsx" }, // JavaScript
+		{ "julia", "jl" }, // Julia
+		{ "julia-repl", "" }, // Julia REPL
+		{ "kotlin", "kt" }, // Kotlin
+		{ "tex", "" }, // LaTeX
+		{ "leaf", "" }, // Leaf
+		{ "lasso", "ls, lassoscript" }, // Lasso
+		{ "less", "" }, // Less
+		{ "ldif", "" }, // LDIF
+		{ "lisp", "" }, // Lisp
+		{ "livecodeserver", "" }, // LiveCode Server
+		{ "livescript", "ls" }, // LiveScript
+		{ "lua", "pluto" }, // Lua
+		{ "makefile", "mk, mak, make" }, // Makefile
+		{ "markdown", "md, mkdown, mkd" }, // Markdown
+		{ "mathematica", "mma, wl" }, // Mathematica
+		{ "matlab", "" }, // Matlab
+		{ "maxima", "" }, // Maxima
+		{ "mel", "" }, // Maya Embedded Language
+		{ "mercury", "" }, // Mercury
+		{ "mips", "mipsasm" }, // MIPS Assembler
+		{ "mizar", "" }, // Mizar
+		{ "mojolicious", "" }, // Mojolicious
+		{ "monkey", "" }, // Monkey
+		{ "moonscript", "moon" }, // Moonscript
+		{ "n1ql", "" }, // N1QL
+		{ "nsis", "" }, // NSIS
+		{ "nginx", "nginxconf" }, // Nginx
+		{ "nim", "nimrod" }, // Nim
+		{ "nix", "" }, // Nix
+		{ "ocaml", "ml" }, // OCaml
+		{ "objectivec", "mm, objc, obj-c, obj-c++, objective-c++" }, // Objective C
+		{ "openscad", "scad" }, // OpenSCAD
+		{ "ruleslanguage", "" }, // Oracle Rules Language
+		{ "oxygene", "" }, // Oxygene
+		{ "pf", "pf.conf" }, // PF
+		{ "php", "" }, // PHP
+		{ "parser3", "" }, // Parser3
+		{ "perl", "pl, pm" }, // Perl
+		{ "plaintext", "txt, text" }, // Plaintext
+		{ "pony", "" }, // Pony
+		{ "pgsql", "postgres, postgresql" }, // PostgreSQL & PL/pgSQL
+		{ "powershell", "ps, ps1" }, // PowerShell
+		{ "processing", "" }, // Processing
+		{ "prolog", "" }, // Prolog
+		{ "properties", "" }, // Properties
+		{ "proto", "protobuf" }, // Protocol Buffers
+		{ "puppet", "pp" }, // Puppet
+		{ "python", "py, gyp" }, // Python
+		{ "profile", "" }, // Python profiler results
+		{ "python-repl", "pycon" }, // Python REPL
+		{ "k", "kdb" }, // Q
+		{ "qml", "" }, // QML
+		{ "r", "" }, // R
+		{ "reasonml", "re" }, // ReasonML
+		{ "rib", "" }, // RenderMan RIB
+		{ "rsl", "" }, // RenderMan RSL
+		{ "graph", "instances" }, // Roboconf
+		{ "ruby", "rb, gemspec, podspec, thor, irb" }, // Ruby
+		{ "rust", "rs" }, // Rust
+		{ "SAS", "sas" }, // SAS
+		{ "scss", "" }, // SCSS
+		{ "sql", "" }, // SQL
+		{ "p21", "step, stp" }, // STEP Part 21
+		{ "scala", "" }, // Scala
+		{ "scheme", "" }, // Scheme
+		{ "scilab", "sci" }, // Scilab
+		{ "shell", "console" }, // Shell
+		{ "smali", "" }, // Smali
+		{ "smalltalk", "st" }, // Smalltalk
+		{ "sml", "ml" }, // SML
+		{ "stan", "stanfuncs" }, // Stan
+		{ "stata", "" }, // Stata
+		{ "stylus", "styl" }, // Stylus
+		{ "subunit", "" }, // SubUnit
+		{ "svelte", "" }, // Svelte 	highlight.svelte
+		{ "swift", "" }, // Swift
+		{ "tcl", "tk" }, // Tcl
+		{ "tap", "" }, // Test Anything Protocol
+		{ "thrift", "" }, // Thrift
+		{ "toit", "" }, // Toit 	toit-highlight
+		{ "tp", "" }, // TP
+		{ "twig", "craftcms" }, // Twig
+		{ "typescript", "ts, tsx, mts, cts" }, // TypeScript
+		{ "vbnet", "vb" }, // VB.Net
+		{ "vbscript", "vbs" }, // VBScript
+		{ "vhdl", "" }, // VHDL
+		{ "vala", "" }, // Vala
+		{ "verilog", "v" }, // Verilog
+		{ "vim", "" }, // Vim Script
+		{ "axapta", "x++" }, // X++
+		{ "x86asm", "" }, // x86 Assembly
+		{ "xl", "tao" }, // XL
+		{ "xquery", "xpath, xq, xqm" }, // XQuery
+		{ "yml", "yaml" }, // YAML
+		{ "zephir", "zep" }, // Zephir
+	};
+
+
+	public static HashSet<string> Languages => new(
+		LanguageMapping.Keys
+			.Concat(LanguageMapping.Values
+				.SelectMany(v => v.Split(',').Select(a => a.Trim()))
+				.Where(v => !string.IsNullOrWhiteSpace(v))
+			)
+		, StringComparer.OrdinalIgnoreCase
+	);
+}

tests/authoring/Blocks/CodeBlocks/CodeBlocks.fs

@@ -0,0 +1,18 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+module ``block elements``.``code blocks``
+
+open Xunit
+open authoring
+
+type ``warns on invalid language`` () =
+    static let markdown = Setup.Markdown """
+```not-a-valid-language
+```
+"""
+
+    [<Fact>]
+    let ``validate HTML: generates link and alt attr`` () =
+        markdown |> hasWarning "Unknown language: not-a-valid-language"

tests/authoring/Framework/ErrorCollectorAssertions.fs

@@ -29,3 +29,14 @@ module DiagnosticsCollectorAssertions =
                                    |> List.ofArray
         let message = errorDiagnostics.FirstOrDefault().Message
         test <@ message.Contains(expected) @>
+
+    [<DebuggerStepThrough>]
+    let hasWarning (expected: string) (actual: Lazy<GeneratorResults>) =
+        let actual = actual.Value
+        actual.Context.Collector.Warnings |> shouldBeGreaterThan 0
+        let errorDiagnostics = actual.Context.Collector.Diagnostics
+                                   .Where(fun d -> d.Severity = Severity.Warning)
+                                   .ToArray()
+                                   |> List.ofArray
+        let message = errorDiagnostics.FirstOrDefault().Message
+        test <@ message.Contains(expected) @>

tests/authoring/authoring.fsproj

@@ -44,4 +44,8 @@
     <Compile Include="Generator\LinkReferenceFile.fs" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Compile Include="Blocks\CodeBlocks\CodeBlocks.fs" />
+  </ItemGroup>
+
 </Project>