add in tests for config.go

config_test.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"github.com/spf13/viper"
+	"os"
+	"os/exec"
+	"testing"
+)
+
+func TestWithDefaultConfigFile(t *testing.T) {
+	// blank out all of viper's configs
+	viper.Reset()
+	// process the default config
+	HandleConfigFile("logstation.default.conf")
+
+	// Should have 3 log files processed
+	var parsedLogs = len(viper.GetStringSlice("logs"))
+	var expectedLogs = 3
+	if parsedLogs != expectedLogs {
+		t.Errorf("Should have had %d log files. Ended up with %d", expectedLogs, parsedLogs)
+	}
+
+	// Should have a logStationName called "logstation"
+	var parsedName = viper.GetString("logStationName")
+	var expectedName = "logstation"
+	if parsedName != expectedName {
+		t.Errorf("Should have had a logstation name of \"%s\". Ended up with %s", expectedName, parsedName)
+	}
+}
+
+func TestBadPath(t *testing.T) {
+	// blank out all of viper's configs
+	viper.Reset()
+	// attempt to remove logstation.conf
+	err := os.Remove("logstation.conf")
+	if !(err == nil || os.IsNotExist(err)) { // continue if no errors or if the conf file doesn't exist
+		panic(err)
+	}
+
+	// If DO_IT is set, lets run the test
+	if os.Getenv("DO_IT") == "1" {
+		HandleConfigFile("thisfiledoesntexist.conf")
+		return
+	}
+	// Setup a subprocess to run the test
+	// follows the ideas from Go Dev Andrew Gerrand in his Testing Techniques talk
+	//  https://go.dev/talks/2014/testing.slide#23
+	cmd := exec.Command(os.Args[0], "-test.run=TestBadPath")
+	cmd.Env = append(os.Environ(), "DO_IT=1")
+	err = cmd.Run()
+	if err == nil {
+		// it ran fine. let's check if it wrote the log file
+		_, err = os.Stat("logstation.conf")
+		if err == nil {
+			return // logstation.conf exists! Test passes
+		} else {
+			t.Fatalf("Looks like the logstation.conf file doesn't exist. There was a problem checking for it. logstation should have made it and exited cleanly for you. err: %v", err)
+		}
+	}
+	t.Fatalf("process ran with err %v, want exit status 0 or nil", err)
+}