Improve incompatible snapshot load error message (#264)

Co-authored-by: Anisa Oshafi <anisaoshafi@gmail.com>

Author: gtsiolis

internal/emulator/aws/client.go

@@ -197,7 +197,7 @@ func (c *Client) ImportState(ctx context.Context, host string, src io.Reader, st
 
 	if resp.StatusCode == http.StatusUnprocessableEntity {
 		body, _ := io.ReadAll(resp.Body)
-		return fmt.Errorf("snapshot is incompatible with the running LocalStack version: %s", strings.TrimSpace(string(body)))
+		return fmt.Errorf("%w: %s", snapshot.ErrIncompatibleSnapshot, strings.TrimSpace(string(body)))
 	}
 	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)
@@ -247,7 +247,7 @@ func (c *Client) LoadPodSnapshot(ctx context.Context, host, podName, authToken,
 
 	if resp.StatusCode == http.StatusUnprocessableEntity {
 		body, _ := io.ReadAll(resp.Body)
-		return nil, fmt.Errorf("snapshot is incompatible with the running LocalStack version: %s", strings.TrimSpace(string(body)))
+		return nil, fmt.Errorf("%w: %s", snapshot.ErrIncompatibleSnapshot, strings.TrimSpace(string(body)))
 	}
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)

internal/snapshot/load.go

@@ -4,6 +4,7 @@ package snapshot
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -20,6 +21,8 @@ const (
 	MergeStrategyService       = "service-merge"
 )
 
+var ErrIncompatibleSnapshot = errors.New("snapshot is incompatible with the running LocalStack version")
+
 func ValidateMergeStrategy(strategy string) error {
 	switch strategy {
 	case MergeStrategyAccountRegion, MergeStrategyOverwrite, MergeStrategyService:
@@ -86,7 +89,15 @@ func load(ctx context.Context, rt runtime.Runtime, containers []config.Container
 		}
 	}()
 
-	return do()
+	err = do()
+	if errors.Is(err, ErrIncompatibleSnapshot) {
+		sink.Emit(output.ErrorEvent{
+			Title:   "Could not load snapshot",
+			Summary: "Snapshot is incompatible with the running LocalStack version",
+		})
+		return output.NewSilentError(err)
+	}
+	return err
 }
 
 func LoadLocal(ctx context.Context, rt runtime.Runtime, containers []config.ContainerConfig, client LocalLoadClient, host, src, strategy string, starter Starter, sink output.Sink) error {

internal/snapshot/load_test.go

@@ -106,6 +106,52 @@ func TestLoadLocal_ImportError(t *testing.T) {
 	assert.Contains(t, err.Error(), "incompatible version")
 }
 
+func TestLoadLocal_IncompatibleSnapshot_StructuredError(t *testing.T) {
+	t.Parallel()
+	src := writeSnapshotFile(t, "ZIP_DATA")
+	importErr := fmt.Errorf("%w: Pod state is incompatible with the current LocalStack version", snapshot.ErrIncompatibleSnapshot)
+	client := mockLocalClientReturning(t, importErr)
+	sink, getEvents := captureEvents(t)
+
+	err := snapshot.LoadLocal(context.Background(), healthyRunningMock(t), awsContainers, client, "", src, "", nopStarter, sink)
+	require.Error(t, err)
+	assert.True(t, output.IsSilent(err), "incompatible-snapshot error should be silent so it isn't double-rendered")
+
+	var errEvent *output.ErrorEvent
+	for _, e := range getEvents() {
+		if ev, ok := e.(output.ErrorEvent); ok {
+			errEvent = &ev
+		}
+	}
+	require.NotNil(t, errEvent, "a structured ErrorEvent should have been emitted")
+	assert.Equal(t, "Could not load snapshot", errEvent.Title)
+	assert.Equal(t, "Snapshot is incompatible with the running LocalStack version", errEvent.Summary)
+}
+
+func TestLoadPod_IncompatibleSnapshot_StructuredError(t *testing.T) {
+	t.Parallel()
+	ctrl := gomock.NewController(t)
+	loader := NewMockPodLoader(ctrl)
+	loadErr := fmt.Errorf("%w: Pod state is incompatible with the current LocalStack version", snapshot.ErrIncompatibleSnapshot)
+	loader.EXPECT().LoadPodSnapshot(gomock.Any(), gomock.Any(), "my-baseline", "test-token", gomock.Any()).
+		Return(nil, loadErr)
+
+	sink, getEvents := captureEvents(t)
+	err := snapshot.LoadPod(context.Background(), healthyRunningMock(t), awsContainers, loader, "", "my-baseline", "test-token", "", nopStarter, sink)
+	require.Error(t, err)
+	assert.True(t, output.IsSilent(err))
+
+	var errEvent *output.ErrorEvent
+	for _, e := range getEvents() {
+		if ev, ok := e.(output.ErrorEvent); ok {
+			errEvent = &ev
+		}
+	}
+	require.NotNil(t, errEvent, "a structured ErrorEvent should have been emitted")
+	assert.Equal(t, "Could not load snapshot", errEvent.Title)
+	assert.Equal(t, "Snapshot is incompatible with the running LocalStack version", errEvent.Summary)
+}
+
 func TestLoadLocal_FileNotFound(t *testing.T) {
 	t.Parallel()
 	ctrl := gomock.NewController(t)