Function TestGetPrecedingSnapshot

internal/diff/diff_test.go:511–531

Tests GetPrecedingSnapshot function - GetPrecedingSnapshot with an invalid snapshot id and expect an error; - Add a snapshot, expect an error from GetPrecedingSnapshot since there is only a single snapshot in the repo; - Subsequently add more snapshots and GetPrecedingSnapshot the immediately preced

(t *testing.T)

//   - Subsequently add more snapshots and GetPrecedingSnapshot the immediately
//     preceding with no error.
func TestGetPrecedingSnapshot(t *testing.T) {
	ctx, env := repotesting.NewEnvironment(t, repotesting.FormatNotImportant)
	manifests := getManifests(t)

	_, err := diff.GetPrecedingSnapshot(ctx, env.RepositoryWriter, "non_existent_snapshot_ID")
	require.Error(t, err, "expect error when calling GetPrecedingSnapshot with a wrong snapshotID")

	initialSnapshotManifestID := mustSaveSnapshot(t, env.RepositoryWriter, manifests["initial_snapshot"])
	_, err = diff.GetPrecedingSnapshot(ctx, env.RepositoryWriter, string(initialSnapshotManifestID))
	require.Error(t, err, "expect error when there is a single snapshot in the repo")

	intermediateSnapshotManifestID := mustSaveSnapshot(t, env.RepositoryWriter, manifests["intermediate_snapshot"])
	gotManID, err := diff.GetPrecedingSnapshot(ctx, env.RepositoryWriter, string(intermediateSnapshotManifestID))
	require.NoError(t, err)
	require.Equal(t, initialSnapshotManifestID, gotManID.ID)

	latestSnapshotManifestID := mustSaveSnapshot(t, env.RepositoryWriter, manifests["latest_snapshot"])
	gotManID2, err := diff.GetPrecedingSnapshot(ctx, env.RepositoryWriter, string(latestSnapshotManifestID))
	require.NoError(t, err)
	require.Equal(t, intermediateSnapshotManifestID, gotManID2.ID)
}

// First call GetTwoLatestSnapshots with insufficient snapshots in the repo and
// expect an error;