FastCGI: some simple tests for buildEnv

More tests are needed for the other environmental variables.
These tests were specifically made for testing of IP addresses.

middleware/fastcgi/fastcgi_test.go

 package fastcgi
 
 import (
+	"net/http"
+	"net/url"
 	"testing"
 )
 
@@ -29,3 +31,65 @@ func TestRuleParseAddress(t *testing.T) {
 	}
 
 }
+
+func BuildEnvSingle(r *http.Request, rule Rule, fpath string, envExpected map[string]string, t *testing.T) {
+
+	h := Handler{}
+
+	env, err := h.buildEnv(r, rule, fpath)
+	if err != nil {
+		t.Error("Unexpected error:", err.Error())
+	}
+
+	for k, v := range envExpected {
+		if env[k] != v {
+			t.Errorf("Unexpected %v. Got %v, expected %v", k, env[k], v)
+		}
+	}
+
+}
+
+func TestBuildEnv(t *testing.T) {
+
+	rule := Rule{}
+	url, err := url.Parse("http://localhost:2015/fgci_test.php?test=blabla")
+	if err != nil {
+		t.Error("Unexpected error:", err.Error())
+	}
+
+	r := http.Request{
+		Method:     "GET",
+		URL:        url,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Host:       "localhost:2015",
+		RemoteAddr: "[2b02:1810:4f2d:9400:70ab:f822:be8a:9093]:51688",
+		RequestURI: "/fgci_test.php",
+	}
+
+	fpath := "/fgci_test.php"
+
+	var envExpected = map[string]string{
+		"REMOTE_ADDR":     "[2b02:1810:4f2d:9400:70ab:f822:be8a:9093]",
+		"REMOTE_PORT":     "51688",
+		"SERVER_PROTOCOL": "HTTP/1.1",
+		"QUERY_STRING":    "test=blabla",
+		"REQUEST_METHOD":  "GET",
+		"HTTP_HOST":       "localhost:2015",
+	}
+
+	// 1. Test for full canonical IPv6 address
+	BuildEnvSingle(&r, rule, fpath, envExpected, t)
+
+	// 2. Test for shorthand notation of IPv6 address
+	r.RemoteAddr = "[::1]:51688"
+	envExpected["REMOTE_ADDR"] = "[::1]"
+	BuildEnvSingle(&r, rule, fpath, envExpected, t)
+
+	// 3. Test for IPv4 address
+	r.RemoteAddr = "192.168.0.10:51688"
+	envExpected["REMOTE_ADDR"] = "192.168.0.10"
+	BuildEnvSingle(&r, rule, fpath, envExpected, t)
+
+}