[pkg/ottl] Return nil on errors

pkg/ottl/ottlfuncs/func_fnv.go

@@ -44,9 +44,9 @@ func FNVHashString[K any](target ottl.StringGetter[K]) (ottl.ExprFunc[K], error)
 		hash := fnv.New64a()
 		_, err1 := hash.Write([]byte(val))
 		if err1 != nil {
-			return val, err1
+			return nil, err1
 		}
 		hashValue := hash.Sum64()
-		return hashValue, nil
+		return int64(hashValue), nil
 	}, nil
 }

pkg/ottl/ottlfuncs/func_fnv_test.go

@@ -22,7 +22,7 @@ func Test_FNV(t *testing.T) {
 		{
 			name:     "string",
 			value:    "hello world",
-			expected: uint64(8618312879776256743),
+			expected: int64(8618312879776256743),
 		},
 		{
 			name:     "empty string",

pkg/ottl/ottlfuncs/func_sha1.go

@@ -8,7 +8,6 @@ import (
 	"crypto/sha1" // #nosec
 	"encoding/hex"
 	"fmt"
-	"io"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
 )
@@ -44,8 +43,9 @@ func SHA1HashString[K any](target ottl.StringGetter[K]) (ottl.ExprFunc[K], error
 		}
 
 		hash := sha1.New() // #nosec
-		if _, err := io.WriteString(hash, val); err != nil {
-			return val, err
+		_, err1 := hash.Write([]byte(val))
+		if err1 != nil {
+			return nil, err1
 		}
 		hashValue := hex.EncodeToString(hash.Sum(nil))
 		return hashValue, nil

pkg/ottl/ottlfuncs/func_sha256.go

@@ -45,10 +45,9 @@ func SHA256HashString[K any](target ottl.StringGetter[K]) (ottl.ExprFunc[K], err
 		hash := sha256.New()
 		_, err1 := hash.Write([]byte(val))
 		if err1 != nil {
-			return val, err1
+			return nil, err1
 		}
 		hashValue := hex.EncodeToString(hash.Sum(nil))
-		fmt.Print(hashValue)
 		return hashValue, nil
 	}, nil
 }