From 109dce7ea5d32e63a96a2c234e991ea3ea470e77 Mon Sep 17 00:00:00 2001
From: Alec Thomas <alec@swapoff.org>
Date: Thu, 5 Mar 2020 11:27:53 +1100
Subject: [PATCH] Expand variables in config paths.

---
 kong.go    | 7 ++++++-
 options.go | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/kong.go b/kong.go
index 882e4ad..3a61567 100644
--- a/kong.go
+++ b/kong.go
@@ -338,9 +338,14 @@ func (k *Kong) FatalIfErrorf(err error, args ...interface{}) {
 
 // LoadConfig from path using the loader configured via Configuration(loader).
 //
-// "path" will have ~/ expanded.
+// "path" will have ~ and any variables expanded.
 func (k *Kong) LoadConfig(path string) (Resolver, error) {
+	var err error
 	path = ExpandPath(path)
+	path, err = interpolate(path, k.vars)
+	if err != nil {
+		return nil, err
+	}
 	r, err := os.Open(path) // nolint: gas
 	if err != nil {
 		return nil, err
diff --git a/options.go b/options.go
index 66fd633..1464d71 100644
--- a/options.go
+++ b/options.go
@@ -235,7 +235,7 @@ type ConfigurationLoader func(r io.Reader) (Resolver, error)
 //
 // Note: The JSON function is a ConfigurationLoader.
 //
-// ~ expansion will occur on the provided paths.
+// ~ and variable expansion will occur on the provided paths.
 func Configuration(loader ConfigurationLoader, paths ...string) Option {
 	return OptionFunc(func(k *Kong) error {
 		k.loader = loader