diff --git a/cli/command/completion/functions.go b/cli/command/completion/functions.go
index b217ec54b05d..deda08e7ba92 100644
--- a/cli/command/completion/functions.go
+++ b/cli/command/completion/functions.go
@@ -59,7 +59,7 @@ func ContainerNames(dockerCLI APIClientProvider, all bool, filters ...func(conta
 		for _, ctr := range list {
 			skip := false
 			for _, fn := range filters {
-				if !fn(ctr) {
+				if fn != nil && !fn(ctr) {
 					skip = true
 					break
 				}
diff --git a/cli/command/completion/functions_test.go b/cli/command/completion/functions_test.go
index a4bb6f543857..aacd9769e19e 100644
--- a/cli/command/completion/functions_test.go
+++ b/cli/command/completion/functions_test.go
@@ -1,15 +1,350 @@
 package completion
 
 import (
+	"context"
+	"errors"
+	"sort"
 	"testing"
 
+	"github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/api/types/filters"
+	"github.com/docker/docker/api/types/image"
+	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/api/types/volume"
+	"github.com/docker/docker/client"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/spf13/cobra"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
+	"gotest.tools/v3/env"
 )
 
+type fakeCLI struct {
+	*fakeClient
+}
+
+// Client implements [APIClientProvider].
+func (c fakeCLI) Client() client.APIClient {
+	return c.fakeClient
+}
+
+type fakeClient struct {
+	client.Client
+	containerListFunc func(options container.ListOptions) ([]container.Summary, error)
+	imageListFunc     func(options image.ListOptions) ([]image.Summary, error)
+	networkListFunc   func(ctx context.Context, options network.ListOptions) ([]network.Summary, error)
+	volumeListFunc    func(filter filters.Args) (volume.ListResponse, error)
+}
+
+func (c *fakeClient) ContainerList(_ context.Context, options container.ListOptions) ([]container.Summary, error) {
+	if c.containerListFunc != nil {
+		return c.containerListFunc(options)
+	}
+	return []container.Summary{}, nil
+}
+
+func (c *fakeClient) ImageList(_ context.Context, options image.ListOptions) ([]image.Summary, error) {
+	if c.imageListFunc != nil {
+		return c.imageListFunc(options)
+	}
+	return []image.Summary{}, nil
+}
+
+func (c *fakeClient) NetworkList(ctx context.Context, options network.ListOptions) ([]network.Summary, error) {
+	if c.networkListFunc != nil {
+		return c.networkListFunc(ctx, options)
+	}
+	return []network.Inspect{}, nil
+}
+
+func (c *fakeClient) VolumeList(_ context.Context, options volume.ListOptions) (volume.ListResponse, error) {
+	if c.volumeListFunc != nil {
+		return c.volumeListFunc(options.Filters)
+	}
+	return volume.ListResponse{}, nil
+}
+
+func TestCompleteContainerNames(t *testing.T) {
+	tests := []struct {
+		doc              string
+		showAll, showIDs bool
+		filters          []func(container.Summary) bool
+		containers       []container.Summary
+		expOut           []string
+		expOpts          container.ListOptions
+		expDirective     cobra.ShellCompDirective
+	}{
+		{
+			doc:          "no results",
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:     "all containers",
+			showAll: true,
+			containers: []container.Summary{
+				{ID: "id-c", State: "running", Names: []string{"/container-c", "/container-c/link-b"}},
+				{ID: "id-b", State: "created", Names: []string{"/container-b"}},
+				{ID: "id-a", State: "exited", Names: []string{"/container-a"}},
+			},
+			expOut:       []string{"container-c", "container-c/link-b", "container-b", "container-a"},
+			expOpts:      container.ListOptions{All: true},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:     "all containers with ids",
+			showAll: true,
+			showIDs: true,
+			containers: []container.Summary{
+				{ID: "id-c", State: "running", Names: []string{"/container-c", "/container-c/link-b"}},
+				{ID: "id-b", State: "created", Names: []string{"/container-b"}},
+				{ID: "id-a", State: "exited", Names: []string{"/container-a"}},
+			},
+			expOut:       []string{"id-c", "container-c", "container-c/link-b", "id-b", "container-b", "id-a", "container-a"},
+			expOpts:      container.ListOptions{All: true},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:     "only running containers",
+			showAll: false,
+			containers: []container.Summary{
+				{ID: "id-c", State: "running", Names: []string{"/container-c", "/container-c/link-b"}},
+			},
+			expOut:       []string{"container-c", "container-c/link-b"},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:     "with filter",
+			showAll: true,
+			filters: []func(container.Summary) bool{
+				func(container container.Summary) bool { return container.State == "created" },
+			},
+			containers: []container.Summary{
+				{ID: "id-c", State: "running", Names: []string{"/container-c", "/container-c/link-b"}},
+				{ID: "id-b", State: "created", Names: []string{"/container-b"}},
+				{ID: "id-a", State: "exited", Names: []string{"/container-a"}},
+			},
+			expOut:       []string{"container-b"},
+			expOpts:      container.ListOptions{All: true},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:     "multiple filters",
+			showAll: true,
+			filters: []func(container.Summary) bool{
+				func(container container.Summary) bool { return container.ID == "id-a" },
+				func(container container.Summary) bool { return container.State == "created" },
+			},
+			containers: []container.Summary{
+				{ID: "id-c", State: "running", Names: []string{"/container-c", "/container-c/link-b"}},
+				{ID: "id-b", State: "created", Names: []string{"/container-b"}},
+				{ID: "id-a", State: "created", Names: []string{"/container-a"}},
+			},
+			expOut:       []string{"container-a"},
+			expOpts:      container.ListOptions{All: true},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:          "with error",
+			expDirective: cobra.ShellCompDirectiveError,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			if tc.showIDs {
+				t.Setenv("DOCKER_COMPLETION_SHOW_CONTAINER_IDS", "yes")
+			}
+			comp := ContainerNames(fakeCLI{&fakeClient{
+				containerListFunc: func(opts container.ListOptions) ([]container.Summary, error) {
+					assert.Check(t, is.DeepEqual(opts, tc.expOpts, cmpopts.IgnoreUnexported(container.ListOptions{}, filters.Args{})))
+					if tc.expDirective == cobra.ShellCompDirectiveError {
+						return nil, errors.New("some error occurred")
+					}
+					return tc.containers, nil
+				},
+			}}, tc.showAll, tc.filters...)
+
+			containers, directives := comp(&cobra.Command{}, nil, "")
+			assert.Check(t, is.Equal(directives&tc.expDirective, tc.expDirective))
+			assert.Check(t, is.DeepEqual(containers, tc.expOut))
+		})
+	}
+}
+
+func TestCompleteEnvVarNames(t *testing.T) {
+	env.PatchAll(t, map[string]string{
+		"ENV_A": "hello-a",
+		"ENV_B": "hello-b",
+	})
+	values, directives := EnvVarNames(nil, nil, "")
+	assert.Check(t, is.Equal(directives&cobra.ShellCompDirectiveNoFileComp, cobra.ShellCompDirectiveNoFileComp), "Should not perform file completion")
+
+	sort.Strings(values)
+	expected := []string{"ENV_A", "ENV_B"}
+	assert.Check(t, is.DeepEqual(values, expected))
+}
+
+func TestCompleteFileNames(t *testing.T) {
+	values, directives := FileNames(nil, nil, "")
+	assert.Check(t, is.Equal(directives, cobra.ShellCompDirectiveDefault))
+	assert.Check(t, is.Len(values, 0))
+}
+
+func TestCompleteFromList(t *testing.T) {
+	expected := []string{"one", "two", "three"}
+
+	values, directives := FromList(expected...)(nil, nil, "")
+	assert.Check(t, is.Equal(directives&cobra.ShellCompDirectiveNoFileComp, cobra.ShellCompDirectiveNoFileComp), "Should not perform file completion")
+	assert.Check(t, is.DeepEqual(values, expected))
+}
+
+func TestCompleteImageNames(t *testing.T) {
+	tests := []struct {
+		doc          string
+		images       []image.Summary
+		expOut       []string
+		expDirective cobra.ShellCompDirective
+	}{
+		{
+			doc:          "no results",
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc: "with results",
+			images: []image.Summary{
+				{RepoTags: []string{"image-c:latest", "image-c:other"}},
+				{RepoTags: []string{"image-b:latest", "image-b:other"}},
+				{RepoTags: []string{"image-a:latest", "image-a:other"}},
+			},
+			expOut:       []string{"image-c:latest", "image-c:other", "image-b:latest", "image-b:other", "image-a:latest", "image-a:other"},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:          "with error",
+			expDirective: cobra.ShellCompDirectiveError,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			comp := ImageNames(fakeCLI{&fakeClient{
+				imageListFunc: func(options image.ListOptions) ([]image.Summary, error) {
+					if tc.expDirective == cobra.ShellCompDirectiveError {
+						return nil, errors.New("some error occurred")
+					}
+					return tc.images, nil
+				},
+			}})
+
+			volumes, directives := comp(&cobra.Command{}, nil, "")
+			assert.Check(t, is.Equal(directives&tc.expDirective, tc.expDirective))
+			assert.Check(t, is.DeepEqual(volumes, tc.expOut))
+		})
+	}
+}
+
+func TestCompleteNetworkNames(t *testing.T) {
+	tests := []struct {
+		doc          string
+		networks     []network.Summary
+		expOut       []string
+		expDirective cobra.ShellCompDirective
+	}{
+		{
+			doc:          "no results",
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc: "with results",
+			networks: []network.Summary{
+				{ID: "nw-c", Name: "network-c"},
+				{ID: "nw-b", Name: "network-b"},
+				{ID: "nw-a", Name: "network-a"},
+			},
+			expOut:       []string{"network-c", "network-b", "network-a"},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:          "with error",
+			expDirective: cobra.ShellCompDirectiveError,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			comp := NetworkNames(fakeCLI{&fakeClient{
+				networkListFunc: func(ctx context.Context, options network.ListOptions) ([]network.Summary, error) {
+					if tc.expDirective == cobra.ShellCompDirectiveError {
+						return nil, errors.New("some error occurred")
+					}
+					return tc.networks, nil
+				},
+			}})
+
+			volumes, directives := comp(&cobra.Command{}, nil, "")
+			assert.Check(t, is.Equal(directives&tc.expDirective, tc.expDirective))
+			assert.Check(t, is.DeepEqual(volumes, tc.expOut))
+		})
+	}
+}
+
+func TestCompleteNoComplete(t *testing.T) {
+	values, directives := NoComplete(nil, nil, "")
+	assert.Check(t, is.Equal(directives, cobra.ShellCompDirectiveNoFileComp))
+	assert.Check(t, is.Len(values, 0))
+}
+
 func TestCompletePlatforms(t *testing.T) {
 	values, directives := Platforms(nil, nil, "")
 	assert.Check(t, is.Equal(directives&cobra.ShellCompDirectiveNoFileComp, cobra.ShellCompDirectiveNoFileComp), "Should not perform file completion")
 	assert.Check(t, is.DeepEqual(values, commonPlatforms))
 }
+
+func TestCompleteVolumeNames(t *testing.T) {
+	tests := []struct {
+		doc          string
+		volumes      []*volume.Volume
+		expOut       []string
+		expDirective cobra.ShellCompDirective
+	}{
+		{
+			doc:          "no results",
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc: "with results",
+			volumes: []*volume.Volume{
+				{Name: "volume-c"},
+				{Name: "volume-b"},
+				{Name: "volume-a"},
+			},
+			expOut:       []string{"volume-c", "volume-b", "volume-a"},
+			expDirective: cobra.ShellCompDirectiveNoFileComp,
+		},
+		{
+			doc:          "with error",
+			expDirective: cobra.ShellCompDirectiveError,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			comp := VolumeNames(fakeCLI{&fakeClient{
+				volumeListFunc: func(filter filters.Args) (volume.ListResponse, error) {
+					if tc.expDirective == cobra.ShellCompDirectiveError {
+						return volume.ListResponse{}, errors.New("some error occurred")
+					}
+					return volume.ListResponse{Volumes: tc.volumes}, nil
+				},
+			}})
+
+			volumes, directives := comp(&cobra.Command{}, nil, "")
+			assert.Check(t, is.Equal(directives&tc.expDirective, tc.expDirective))
+			assert.Check(t, is.DeepEqual(volumes, tc.expOut))
+		})
+	}
+}