Tighten up the golangci-lint config

Author: oschwald

.golangci.yml

@@ -60,6 +60,9 @@ linters:
     gosec:
       excludes:
         - G115
+        # Potential file inclusion via variable - we only open files asked by
+        # the user of the API.
+        - G304
     govet:
       disable:
         - shadow
@@ -135,22 +138,13 @@ linters:
     unparam:
       check-exported: true
   exclusions:
-    generated: lax
-    presets:
-      - comments
-      - common-false-positives
-      - legacy
-      - std-error-handling
+    warn-unused: true
     rules:
       - linters:
           - govet
           - revive
         path: _test.go
         text: 'fieldalignment:'
-    paths:
-      - third_party$
-      - builtin$
-      - examples$
 formatters:
   enable:
     - gci
@@ -166,9 +160,3 @@ formatters:
         - prefix(github.com/oschwald/maxminddb-golang)
     gofumpt:
       extra-rules: true
-  exclusions:
-    generated: lax
-    paths:
-      - third_party$
-      - builtin$
-      - examples$

example_test.go

@@ -14,7 +14,7 @@ func ExampleReader_Lookup_struct() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer db.Close()
+	defer db.Close() //nolint:errcheck // error doesn't matter
 
 	addr := netip.MustParseAddr("81.2.69.142")
 
@@ -39,7 +39,7 @@ func ExampleReader_Lookup_interface() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer db.Close()
+	defer db.Close() //nolint:errcheck // error doesn't matter
 
 	addr := netip.MustParseAddr("81.2.69.142")
 
@@ -61,7 +61,7 @@ func ExampleReader_Networks() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer db.Close()
+	defer db.Close() //nolint:errcheck // error doesn't matter
 
 	for result := range db.Networks() {
 		record := struct {
@@ -108,7 +108,7 @@ func ExampleReader_NetworksWithin() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer db.Close()
+	defer db.Close() //nolint:errcheck // error doesn't matter
 
 	prefix, err := netip.ParsePrefix("1.0.0.0/8")
 	if err != nil {

reader.go

@@ -69,7 +69,7 @@ func Open(file string, options ...ReaderOption) (*Reader, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer mapFile.Close()
+	defer mapFile.Close() //nolint:errcheck // error is generally not relevant
 
 	stats, err := mapFile.Stat()
 	if err != nil {