From 8a0fd2acd5c745f61f6eda6466652c665cdd6623 Mon Sep 17 00:00:00 2001
From: Michael Hanselmann <public@hansmi.ch>
Date: Tue, 4 Feb 2025 22:20:31 +0100
Subject: [PATCH] Use text/template instead of html/template for config
 pre-processing

Commit c95311d1 added support for multiple config formats in addition to
pre-processing using Go's built-in templating system. The
`html/template` package is equivalent to `text/template`, except that
the former automatically escapes characters for inclusion in HTML.

Configurations aren't plain text, but they're also certainly no HTML.
The difference between the packages is noticeable when using `printf
"%q"` for quoting of strings. An example from the included unittest:

* `html/template`: `key = &#34;with space&#34;`
* `text/template`: `key = "with space"`

Signed-off-by: Michael Hanselmann <public@hansmi.ch>
---
 pkg/config/load.go      |  2 +-
 pkg/config/load_test.go | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/pkg/config/load.go b/pkg/config/load.go
index fa814fd0..fa394dda 100644
--- a/pkg/config/load.go
+++ b/pkg/config/load.go
@@ -18,10 +18,10 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"html/template"
 	"os"
 	"path/filepath"
 	"strings"
+	"text/template"
 
 	toml "github.com/pelletier/go-toml/v2"
 	"github.com/samber/lo"
diff --git a/pkg/config/load_test.go b/pkg/config/load_test.go
index b3f77800..980a332a 100644
--- a/pkg/config/load_test.go
+++ b/pkg/config/load_test.go
@@ -112,6 +112,29 @@ func TestLoadServerConfigStrictMode(t *testing.T) {
 	}
 }
 
+func TestRenderWithTemplate(t *testing.T) {
+	tests := []struct {
+		name    string
+		content string
+		want    string
+	}{
+		{"toml", tomlServerContent, tomlServerContent},
+		{"yaml", yamlServerContent, yamlServerContent},
+		{"json", jsonServerContent, jsonServerContent},
+		{"template numeric", `key = {{ 123 }}`, "key = 123"},
+		{"template string", `key = {{ "xyz" }}`, "key = xyz"},
+		{"template quote", `key = {{ printf "%q" "with space" }}`, `key = "with space"`},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			require := require.New(t)
+			got, err := RenderWithTemplate([]byte(test.content), nil)
+			require.NoError(err)
+			require.EqualValues(test.want, string(got))
+		})
+	}
+}
+
 func TestCustomStructStrictMode(t *testing.T) {
 	require := require.New(t)