From 883b9836114c3d9eeb6a716cffb526d5d0be1d72 Mon Sep 17 00:00:00 2001
From: Ethan Frey <ethanfrey@users.noreply.github.com>
Date: Tue, 18 Jul 2017 16:38:31 +0200
Subject: [PATCH] Test ibc header updates with dynamic sets

---
 modules/ibc/errors.go   |  9 +++--
 modules/ibc/handler.go  |  2 +-
 modules/ibc/ibc_test.go | 73 ++++++++++++++++++++++++++++++++++++++++-
 modules/ibc/provider.go |  2 +-
 4 files changed, 78 insertions(+), 8 deletions(-)

diff --git a/modules/ibc/errors.go b/modules/ibc/errors.go
index 5df7a7d33..8fafe7a73 100644
--- a/modules/ibc/errors.go
+++ b/modules/ibc/errors.go
@@ -96,12 +96,11 @@ func IsInvalidProofErr(err error) bool {
 }
 
 func ErrInvalidCommit(err error) error {
-	e := errors.WithMessage(msgInvalidCommit, err, IBCCodeInvalidCommit)
-	fmt.Println("make", e.ErrorCode())
-	return e
+	if err == nil {
+		return nil
+	}
+	return errors.WithMessage(msgInvalidCommit, err, IBCCodeInvalidCommit)
 }
 func IsInvalidCommitErr(err error) bool {
-	// fmt.Println("check", err.(errors.TMError).ErrorCode(), IBCCodeInvalidCommit)
-	fmt.Println("check", IBCCodeInvalidCommit)
 	return errors.HasErrorCode(err, IBCCodeInvalidCommit)
 }
diff --git a/modules/ibc/handler.go b/modules/ibc/handler.go
index 76c584ec1..ee494d7e1 100644
--- a/modules/ibc/handler.go
+++ b/modules/ibc/handler.go
@@ -148,7 +148,7 @@ func (h Handler) updateSeed(ctx basecoin.Context, store state.KVStore,
 
 	// this will import the seed if it is valid in the current context
 	err = cert.Update(seed.Checkpoint, seed.Validators)
-	return res, err
+	return res, ErrInvalidCommit(err)
 }
 
 // createPacket makes sure all permissions are good and the destination
diff --git a/modules/ibc/ibc_test.go b/modules/ibc/ibc_test.go
index 336e1aa2b..903aa6b71 100644
--- a/modules/ibc/ibc_test.go
+++ b/modules/ibc/ibc_test.go
@@ -77,7 +77,7 @@ func TestIBCRegister(t *testing.T) {
 	}
 }
 
-// this tests registration without registrar permissions
+// this tests permission controls on ibc registration
 func TestIBCRegisterPermissions(t *testing.T) {
 	assert := assert.New(t)
 	require := require.New(t)
@@ -155,8 +155,79 @@ func TestIBCRegisterPermissions(t *testing.T) {
 	}
 }
 
+// this verifies that we can properly update the headers on the chain
 func TestIBCUpdate(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
 
+	// this is the root seed, that others are evaluated against
+	keys := certifiers.GenValKeys(7)
+	appHash := []byte{0, 4, 7, 23}
+	start := 100 // initial height
+	root := genEmptySeed(keys, "chain-1", 100, appHash, len(keys))
+
+	keys2 := keys.Extend(2)
+	keys3 := keys2.Extend(2)
+
+	// create the app and register the root of trust (for chain-1)
+	ctx := stack.MockContext("hub", 50)
+	store := state.NewMemKVStore()
+	app := stack.New().Dispatch(stack.WrapHandler(NewHandler()))
+	tx := RegisterChainTx{root}.Wrap()
+	_, err := app.DeliverTx(ctx, store, tx)
+	require.Nil(err, "%+v", err)
+
+	cases := []struct {
+		seed    certifiers.Seed
+		checker checkErr
+	}{
+		// same validator, higher up
+		{
+			genEmptySeed(keys, "chain-1", start+50, []byte{22}, len(keys)),
+			noErr,
+		},
+		// same validator, between existing (not most recent)
+		{
+			genEmptySeed(keys, "chain-1", start+5, []byte{15, 43}, len(keys)),
+			noErr,
+		},
+		// same validators, before root of trust
+		{
+			genEmptySeed(keys, "chain-1", start-8, []byte{11, 77}, len(keys)),
+			IsHeaderNotFoundErr,
+		},
+		// insufficient signatures
+		{
+			genEmptySeed(keys, "chain-1", start+60, []byte{24}, len(keys)/2),
+			IsInvalidCommitErr,
+		},
+		// unregistered chain
+		{
+			genEmptySeed(keys, "chain-2", start+60, []byte{24}, len(keys)/2),
+			IsNotRegisteredErr,
+		},
+		// too much change (keys -> keys3)
+		{
+			genEmptySeed(keys3, "chain-1", start+100, []byte{22}, len(keys3)),
+			IsInvalidCommitErr,
+		},
+		// legit update to validator set (keys -> keys2)
+		{
+			genEmptySeed(keys2, "chain-1", start+90, []byte{33}, len(keys2)),
+			noErr,
+		},
+		// now impossible jump works (keys -> keys2 -> keys3)
+		{
+			genEmptySeed(keys3, "chain-1", start+100, []byte{44}, len(keys3)),
+			noErr,
+		},
+	}
+
+	for i, tc := range cases {
+		tx := UpdateChainTx{tc.seed}.Wrap()
+		_, err := app.DeliverTx(ctx, store, tx)
+		assert.True(tc.checker(err), "%d: %+v", i, err)
+	}
 }
 
 func TestIBCCreatePacket(t *testing.T) {
diff --git a/modules/ibc/provider.go b/modules/ibc/provider.go
index 7f140c3c2..2c508836f 100644
--- a/modules/ibc/provider.go
+++ b/modules/ibc/provider.go
@@ -31,7 +31,7 @@ func newCertifier(store state.KVStore, chainID string, h int) (*certifiers.Inqui
 		seed, err = certifiers.LatestSeed(p)
 	}
 	if err != nil {
-		return nil, err
+		return nil, ErrHeaderNotFound(h)
 	}
 
 	// we have no source for untrusted keys, but use the db to load trusted history