Add GetPrefixListByName helper with test coverage

Author: aweingarten

prefixlists.go

@@ -3,6 +3,7 @@ package linodego
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"time"
 
 	"github.com/linode/linodego/internal/parseabletime"
@@ -59,3 +60,27 @@ func (c *Client) GetPrefixList(ctx context.Context, id int) (*PrefixList, error)
 	endpoint := formatAPIPath("networking/prefixlists/%d", id)
 	return doGETRequest[PrefixList](ctx, c, endpoint)
 }
+
+// GetPrefixListByName finds a Prefix List by its name (e.g., "pl:system:object-storage:us-iad").
+// Returns nil and an error if no matching prefix list is found.
+func (c *Client) GetPrefixListByName(ctx context.Context, name string) (*PrefixList, error) {
+	f := Filter{}
+	f.AddField(Eq, "name", name)
+
+	fJSON, err := f.MarshalJSON()
+	if err != nil {
+		return nil, err
+	}
+
+	opts := ListOptions{Filter: string(fJSON)}
+	lists, err := c.ListPrefixLists(ctx, &opts)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(lists) == 0 {
+		return nil, fmt.Errorf("prefix list with name %q not found", name)
+	}
+
+	return &lists[0], nil
+}

test/unit/prefixlists_test.go

@@ -119,3 +119,68 @@ func TestPrefixList_UnmarshalJSON(t *testing.T) {
 	}
 	assert.Nil(t, prefixList.Deleted)
 }
+
+func TestPrefixLists_GetByName(t *testing.T) {
+	var base ClientBaseCase
+	base.SetUp(t)
+	defer base.TearDown(t)
+
+	response := map[string]any{
+		"data": []map[string]any{
+			{
+				"id":                   999,
+				"name":                 "pl:system:resolvers:us-iad:staging",
+				"description":          "Resolver ACL",
+				"visibility":           "restricted",
+				"source_prefixlist_id": nil,
+				"ipv4":                 []string{"139.144.192.62"},
+				"ipv6":                 []string{"2600:3c05:e001:bc::1"},
+				"version":              7,
+				"created":              "2021-01-01T00:00:00",
+				"updated":              "2021-06-01T00:00:00",
+				"deleted":              nil,
+			},
+		},
+		"page":    1,
+		"pages":   1,
+		"results": 1,
+	}
+
+	base.MockGet("networking/prefixlists", response)
+
+	pl, err := base.Client.GetPrefixListByName(context.Background(), "pl:system:resolvers:us-iad:staging")
+	assert.NoError(t, err)
+	assert.NotNil(t, pl)
+
+	assert.Equal(t, 999, pl.ID)
+	assert.Equal(t, "pl:system:resolvers:us-iad:staging", pl.Name)
+	assert.Equal(t, "Resolver ACL", pl.Description)
+	assert.Equal(t, "restricted", pl.Visibility)
+	assert.Equal(t, 7, pl.Version)
+	if assert.NotNil(t, pl.IPv4) {
+		assert.Equal(t, []string{"139.144.192.62"}, *pl.IPv4)
+	}
+	if assert.NotNil(t, pl.IPv6) {
+		assert.Equal(t, []string{"2600:3c05:e001:bc::1"}, *pl.IPv6)
+	}
+}
+
+func TestPrefixLists_GetByName_NotFound(t *testing.T) {
+	var base ClientBaseCase
+	base.SetUp(t)
+	defer base.TearDown(t)
+
+	response := map[string]any{
+		"data":    []map[string]any{},
+		"page":    1,
+		"pages":   1,
+		"results": 0,
+	}
+
+	base.MockGet("networking/prefixlists", response)
+
+	pl, err := base.Client.GetPrefixListByName(context.Background(), "pl:nonexistent")
+	assert.Error(t, err)
+	assert.Nil(t, pl)
+	assert.Contains(t, err.Error(), "not found")
+}