Refactor environment variables (#21)

* Refactor env var, create a package

* Reorder functions

env/env.go

@@ -0,0 +1,65 @@
+package env
+
+import (
+	"os"
+	"strconv"
+)
+
+// Environment variables, used to override defaults
+const (
+	// Channel/Revision of the service snap (has default)
+	envSnapChannel = "SNAP_CHANNEL"
+
+	// Path to snap instead, used for testing a local snap instead of
+	// downloading from the store
+	envSnapPath = "SNAP_PATH"
+
+	// Toggle the teardown operations during tests (has default)
+	envTeardown = "TEARDOWN"
+)
+
+var (
+	// Defaults
+	snapChannel = "latest/edge"
+	snapPath    = ""
+	teardown    = true
+)
+
+// SnapChannel returns the set snap channel
+func SnapChannel() string {
+	return snapChannel
+}
+
+// SnapPath returns the set path to a local snap
+func SnapPath() string {
+	return snapPath
+}
+
+// SkipTeardownRemoval return
+func Teardown() (skip bool) {
+	return teardown
+}
+
+func init() {
+	loadEnvVars()
+}
+
+// Read environment variables and perform type conversion/casting
+func loadEnvVars() {
+
+	if v := os.Getenv(envSnapChannel); v != "" {
+		snapChannel = v
+	}
+
+	if v := os.Getenv(envSnapPath); v != "" {
+		snapPath = v
+	}
+
+	if v := os.Getenv(envTeardown); v != "" {
+		var err error
+		teardown, err = strconv.ParseBool(v)
+		if err != nil {
+			panic(err)
+		}
+	}
+}

utils/refresh.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/canonical/matter-snap-testing/env"
 	"github.com/stretchr/testify/require"
 )
 
@@ -13,8 +14,8 @@ func TestRefresh(t *testing.T, snapName string) {
 
 		const stableChannel = "latest/stable"
 
-		if ServiceChannel == stableChannel {
-			t.Skipf("Skip refresh on same channel: %s", ServiceChannel)
+		if env.SnapChannel() == stableChannel {
+			t.Skipf("Skip refresh on same channel: %s", env.SnapChannel())
 		}
 
 		// remove and install the older stable revision
@@ -25,14 +26,14 @@ func TestRefresh(t *testing.T, snapName string) {
 
 		t.Cleanup(func() {
 			SnapRemove(t, snapName)
-			SnapInstallFromStore(t, snapName, ServiceChannel)
+			SnapInstallFromStore(t, snapName, env.SnapChannel())
 		})
 
 		originalVersion := SnapVersion(t, snapName)
 		originalRevision := SnapRevision(t, snapName)
 
 		t.Run("check services", func(t *testing.T) {
-			SnapRefresh(t, snapName, ServiceChannel)
+			SnapRefresh(t, snapName, env.SnapChannel())
 			refreshVersion := SnapVersion(t, snapName)
 			refreshRevision = SnapRevision(t, snapName)
 

utils/snap.go

@@ -209,7 +209,3 @@ func SnapServicesActive(t *testing.T, name string) bool {
 	))
 	return strings.TrimSpace(out) == "active"
 }
-
-func LocalServiceSnap() bool {
-	return LocalServiceSnapPath != ""
-}