Add custom theming

highlight_lexer_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/alecthomas/chroma/v2/lexers"
+)
+
+func TestLexerForPathUsesCompleteFilename(t *testing.T) {
+	tests := []struct {
+		path string
+		want string
+	}{
+		{"Dockerfile", "Docker"},
+		{"Makefile", "Makefile"},
+		{"src/component.tsx", "TypeScript"},
+		{"scripts/check.py", "Python"},
+		{".github/workflows/test.yml", "YAML"},
+	}
+	for _, test := range tests {
+		t.Run(test.path, func(t *testing.T) {
+			got := lexerForPath(test.path)
+			lexer := lexers.Get(got)
+			if lexer == nil {
+				t.Fatalf("lexerForPath(%q) = %q, which is not registered", test.path, got)
+			}
+			if lexer.Config().Name != test.want {
+				t.Fatalf("lexerForPath(%q) selected %q, want %q", test.path, lexer.Config().Name, test.want)
+			}
+		})
+	}
+}
+
+func TestLexerForUnknownPathAllowsContentAnalysis(t *testing.T) {
+	if got := lexerForPath("LICENSE.unknown-extension"); got != "" {
+		t.Fatalf("unknown path selected %q instead of allowing content analysis", got)
+	}
+}