From 8334b13144c108fc6e8521a4babe915c37854d29 Mon Sep 17 00:00:00 2001
From: Pieter Claerhout <pieter@yellowduck.be>
Date: Mon, 25 May 2020 10:07:34 +0200
Subject: [PATCH] Better error handling

---
 database.go                | 6 ++++--
 go.mod                     | 4 ++--
 go.sum                     | 4 ++++
 serverapp/handle_lookup.go | 6 ++++++
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/database.go b/database.go
index df2f18d..c57f704 100644
--- a/database.go
+++ b/database.go
@@ -48,9 +48,11 @@ func (database *Database) Lookup(ipaddress string) (*IPLocation, error) {
 	defer db.Close()
 
 	ip := net.ParseIP(ipaddress)
+	if ip == nil {
+		return nil, errors.New("Invalid IP address")
+	}
 
-	err = db.Lookup(ip, &location)
-	if err != nil {
+	if err := db.Lookup(ip, &location); err != nil {
 		return location, err
 	}
 
diff --git a/go.mod b/go.mod
index e56e17b..717e853 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/joho/godotenv v1.3.0
 	github.com/markusthoemmes/goautoneg v0.0.0-20190713162725-c6008fefa5b1 // indirect
 	github.com/oschwald/maxminddb-golang v1.6.0
-	github.com/pieterclaerhout/go-log v1.13.0
-	github.com/pieterclaerhout/go-webserver/v2 v2.0.2
+	github.com/pieterclaerhout/go-log v1.14.0
+	github.com/pieterclaerhout/go-webserver/v2 v2.0.3
 	github.com/pkg/errors v0.9.1
 )
diff --git a/go.sum b/go.sum
index ee4cffa..8995a7d 100644
--- a/go.sum
+++ b/go.sum
@@ -29,8 +29,12 @@ github.com/pieterclaerhout/go-formatter v1.0.4 h1:XKFCBb9aNwazTqhtH1snru/D8E7yXQ
 github.com/pieterclaerhout/go-formatter v1.0.4/go.mod h1:1okQQFUwXCLGTWXoWoh3OGchp3i7KeebwIx/ufmsjks=
 github.com/pieterclaerhout/go-log v1.13.0 h1:Jx12Ou5O7olkB48mD5IdqRWiYt5AHwfuLLDlz5LnDXw=
 github.com/pieterclaerhout/go-log v1.13.0/go.mod h1:Zwdhg00fN6IuEWDvktUpu/XFMC5Y+NWrXyQ1RQHRPjc=
+github.com/pieterclaerhout/go-log v1.14.0 h1:TWh+YvSWdqYeejB15pxa6S8p06kDDLCUz1nfNyqOJPo=
+github.com/pieterclaerhout/go-log v1.14.0/go.mod h1:Zwdhg00fN6IuEWDvktUpu/XFMC5Y+NWrXyQ1RQHRPjc=
 github.com/pieterclaerhout/go-webserver/v2 v2.0.2 h1:7WBPFuNwlEvZDb7ooZRkn0Zxx+2Azrswm53K/XaxaFE=
 github.com/pieterclaerhout/go-webserver/v2 v2.0.2/go.mod h1:LNTKF6X39cC9DtFA2AbHt2kOJK5TwTfB3NtzMxrpjAk=
+github.com/pieterclaerhout/go-webserver/v2 v2.0.3 h1:4jqg7LiAH3jXayGiQDTRWThXQlmS/h1iDIIZyeY03CI=
+github.com/pieterclaerhout/go-webserver/v2 v2.0.3/go.mod h1:lvYt/vW838Slf62NWLOECTWBaUiWCugRsxCKmb9A5Qs=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
diff --git a/serverapp/handle_lookup.go b/serverapp/handle_lookup.go
index 94db672..1778226 100644
--- a/serverapp/handle_lookup.go
+++ b/serverapp/handle_lookup.go
@@ -1,6 +1,7 @@
 package serverapp
 
 import (
+	"errors"
 	"net/http"
 
 	"github.com/pieterclaerhout/go-webserver/v2/binder"
@@ -21,6 +22,11 @@ func (a *serverApp) handleLookup() http.HandlerFunc {
 			return
 		}
 
+		if req.IPAddress == "" {
+			respond.Error(errors.New("No IP address specified")).Write(w, r)
+			return
+		}
+
 		result, err := a.db.Lookup(req.IPAddress)
 		if err != nil {
 			respond.Error(err).Write(w, r)