From 1c08b354030e3cec25dab34f6510650550bc3fb3 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@pluranimity.org>
Date: Wed, 14 Nov 2018 16:00:15 +0100
Subject: [PATCH 1/2] Initial pass

---
 PENDING.md                 |  1 +
 cmd/gaia/app/app.go        |  2 ++
 cmd/gaia/app/invariants.go | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 cmd/gaia/app/invariants.go

diff --git a/PENDING.md b/PENDING.md
index 5480b778017b..b2c315675654 100644
--- a/PENDING.md
+++ b/PENDING.md
@@ -31,6 +31,7 @@ FEATURES
 * Gaia
   * [x/gov] [#2479](https://github.com/cosmos/cosmos-sdk/issues/2479) Implemented querier
   for getting governance parameters.
+  * [app] \#2663 - Runtime-assertable invariants
 
 * SDK
     * [simulator] \#2682 MsgEditValidator now looks at the validator's max rate, thus it now succeeds a significant portion of the time
diff --git a/cmd/gaia/app/app.go b/cmd/gaia/app/app.go
index 918bfc67d114..8642da3eeead 100644
--- a/cmd/gaia/app/app.go
+++ b/cmd/gaia/app/app.go
@@ -210,6 +210,8 @@ func (app *GaiaApp) EndBlocker(ctx sdk.Context, req abci.RequestEndBlock) abci.R
 	tags := gov.EndBlocker(ctx, app.govKeeper)
 	validatorUpdates := stake.EndBlocker(ctx, app.stakeKeeper)
 
+	app.assertRuntimeInvariants()
+
 	return abci.ResponseEndBlock{
 		ValidatorUpdates: validatorUpdates,
 		Tags:             tags,
diff --git a/cmd/gaia/app/invariants.go b/cmd/gaia/app/invariants.go
new file mode 100644
index 000000000000..774212e9bd38
--- /dev/null
+++ b/cmd/gaia/app/invariants.go
@@ -0,0 +1,32 @@
+package app
+
+import (
+	"fmt"
+
+	banksim "github.com/cosmos/cosmos-sdk/x/bank/simulation"
+	distrsim "github.com/cosmos/cosmos-sdk/x/distribution/simulation"
+	govsim "github.com/cosmos/cosmos-sdk/x/gov/simulation"
+	"github.com/cosmos/cosmos-sdk/x/mock/simulation"
+	slashingsim "github.com/cosmos/cosmos-sdk/x/slashing/simulation"
+	stakesim "github.com/cosmos/cosmos-sdk/x/stake/simulation"
+)
+
+func (app *GaiaApp) runtimeInvariants() []simulation.Invariant {
+	return []simulation.Invariant{
+		banksim.NonnegativeBalanceInvariant(app.accountKeeper),
+		govsim.AllInvariants(),
+		distrsim.AllInvariants(app.distrKeeper, app.stakeKeeper),
+		stakesim.AllInvariants(app.bankKeeper, app.stakeKeeper,
+			app.feeCollectionKeeper, app.distrKeeper, app.accountKeeper),
+		slashingsim.AllInvariants(),
+	}
+}
+
+func (app *GaiaApp) assertRuntimeInvariants() {
+	invariants := app.runtimeInvariants()
+	for _, inv := range invariants {
+		if err := inv(app.BaseApp); err != nil {
+			panic(fmt.Errorf("invariant broken: %s", err))
+		}
+	}
+}

From 492e9f0313d1b3abb338e8750b97bed95932ba96 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@pluranimity.org>
Date: Wed, 14 Nov 2018 16:43:05 +0100
Subject: [PATCH 2/2] Minor cleanup

---
 cmd/gaia/app/invariants.go | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/cmd/gaia/app/invariants.go b/cmd/gaia/app/invariants.go
index 774212e9bd38..67ec1c71414a 100644
--- a/cmd/gaia/app/invariants.go
+++ b/cmd/gaia/app/invariants.go
@@ -2,31 +2,33 @@ package app
 
 import (
 	"fmt"
+	"time"
 
 	banksim "github.com/cosmos/cosmos-sdk/x/bank/simulation"
 	distrsim "github.com/cosmos/cosmos-sdk/x/distribution/simulation"
-	govsim "github.com/cosmos/cosmos-sdk/x/gov/simulation"
 	"github.com/cosmos/cosmos-sdk/x/mock/simulation"
-	slashingsim "github.com/cosmos/cosmos-sdk/x/slashing/simulation"
 	stakesim "github.com/cosmos/cosmos-sdk/x/stake/simulation"
 )
 
 func (app *GaiaApp) runtimeInvariants() []simulation.Invariant {
 	return []simulation.Invariant{
 		banksim.NonnegativeBalanceInvariant(app.accountKeeper),
-		govsim.AllInvariants(),
-		distrsim.AllInvariants(app.distrKeeper, app.stakeKeeper),
-		stakesim.AllInvariants(app.bankKeeper, app.stakeKeeper,
+		distrsim.ValAccumInvariants(app.distrKeeper, app.stakeKeeper),
+		stakesim.SupplyInvariants(app.bankKeeper, app.stakeKeeper,
 			app.feeCollectionKeeper, app.distrKeeper, app.accountKeeper),
-		slashingsim.AllInvariants(),
+		stakesim.PositivePowerInvariant(app.stakeKeeper),
 	}
 }
 
 func (app *GaiaApp) assertRuntimeInvariants() {
 	invariants := app.runtimeInvariants()
+	start := time.Now()
 	for _, inv := range invariants {
 		if err := inv(app.BaseApp); err != nil {
 			panic(fmt.Errorf("invariant broken: %s", err))
 		}
 	}
+	end := time.Now()
+	diff := end.Sub(start)
+	app.BaseApp.Logger.With("module", "invariants").Info("Asserted all invariants", "duration", diff)
 }