refactor: dependency injection instead of package globals (#57)

* refactor: export Settings type, Setup returns value

* refactor: resolver.Setup takes explicit Settings struct

* refactor: GetHeadersWithoutTrustedHeaders takes explicit header params

* refactor: server constructors take narrow config

* refactor: Router struct with handler methods, remove geoSvc global

* refactor: wire DI through main, remove setting.App references

* refactor: remove App global, use returned Settings

* refactor: update router tests for DI

* chore: fix lint issues — rename ServerTimeouts to Timeouts, fix shadowed variables

router/headers_test.go

@@ -1,11 +1,13 @@
 package router
 
 import (
+	"context"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
-	"github.com/dcarrillo/whatismyip/internal/setting"
+	"github.com/dcarrillo/whatismyip/service"
+	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -27,12 +29,11 @@ Header2: value22
 Header3: value3
 Host: 
 `
-	_, _ = setting.Setup([]string{
-		"-geoip2-city", "city",
-		"-geoip2-asn", "asn",
-		"-trusted-header", trustedHeader,
-		"-trusted-port-header", trustedPortHeader,
-	})
+	svc, _ := service.NewGeo(context.Background(), "../test/GeoIP2-City-Test.mmdb", "../test/GeoLite2-ASN-Test.mmdb")
+	engine := gin.Default()
+	engine.TrustedPlatform = trustedHeader
+	r := NewRouter(svc, trustedHeader, trustedPortHeader, "", false)
+	Setup(engine, r)
 	req, _ := http.NewRequest("GET", "/headers", nil)
 	req.Header = map[string][]string{
 		"Header1": {"value1"},
@@ -43,7 +44,7 @@ Host:
 	req.Header.Set(trustedPortHeader, "1025")
 
 	w := httptest.NewRecorder()
-	app.ServeHTTP(w, req)
+	engine.ServeHTTP(w, req)
 
 	assert.Equal(t, 200, w.Code)
 	assert.Equal(t, contentType.text, w.Header().Get("Content-Type"))