From ae2958a4f9d6901650af60ae3ef05dfd89f98e18 Mon Sep 17 00:00:00 2001
From: Ruslan Usichenko <ruslan.usichenko@namecheap.com>
Date: Sat, 27 Mar 2021 23:41:28 +0200
Subject: [PATCH] helm-diff doesn't include values from stdin for helm3 version

---
 cmd/helm3.go | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/cmd/helm3.go b/cmd/helm3.go
index d65afb61..2e6fc2da 100644
--- a/cmd/helm3.go
+++ b/cmd/helm3.go
@@ -120,7 +120,31 @@ func (d *diffCmd) template(isUpgrade bool) ([]byte, error) {
 		flags = append(flags, "--set-string", stringValue)
 	}
 	for _, valueFile := range d.valueFiles {
-		flags = append(flags, "--values", valueFile)
+		if strings.TrimSpace(valueFile) == "-" {
+			bytes, err := ioutil.ReadAll(os.Stdin)
+			if err != nil {
+				return nil, err
+			}
+
+			tmpfile, err := ioutil.TempFile("", "helm-diff-stdin-values")
+			if err != nil {
+				return nil, err
+			}
+			defer os.Remove(tmpfile.Name())
+
+			if _, err := tmpfile.Write(bytes); err != nil {
+				tmpfile.Close()
+				return nil, err
+			}
+
+			if err := tmpfile.Close(); err != nil {
+				return nil, err
+			}
+
+			flags = append(flags, "--values", tmpfile.Name())
+		} else {
+			flags = append(flags, "--values", valueFile)
+		}
 	}
 	for _, fileValue := range d.fileValues {
 		flags = append(flags, "--set-file", fileValue)