Add length caps for governance proposal titles and descriptions (#3434)

PENDING.md

@@ -45,6 +45,7 @@ IMPROVEMENTS
 * Gaia
   * [\#3418](https://github.com/cosmos/cosmos-sdk/issues/3418) Add vesting account
   genesis validation checks to `GaiaValidateGenesisState`.
+  * [\#3420](https://github.com/cosmos/cosmos-sdk/issues/3420) Added maximum length to governance proposal descriptions and titles
 
 * SDK
   * \#3435 Test that store implementations do not allow nil values

x/gov/errors.go

@@ -46,12 +46,12 @@ func ErrAddressNotStaked(codespace sdk.CodespaceType, address sdk.AccAddress) sd
 	return sdk.NewError(codespace, CodeAddressNotStaked, fmt.Sprintf("Address %s is not staked and is thus ineligible to vote", address))
 }
 
-func ErrInvalidTitle(codespace sdk.CodespaceType, title string) sdk.Error {
-	return sdk.NewError(codespace, CodeInvalidTitle, fmt.Sprintf("Proposal Title '%s' is not valid", title))
+func ErrInvalidTitle(codespace sdk.CodespaceType, errorMsg string) sdk.Error {
+	return sdk.NewError(codespace, CodeInvalidTitle, errorMsg)
 }
 
-func ErrInvalidDescription(codespace sdk.CodespaceType, description string) sdk.Error {
-	return sdk.NewError(codespace, CodeInvalidDescription, fmt.Sprintf("Proposal Desciption '%s' is not valid", description))
+func ErrInvalidDescription(codespace sdk.CodespaceType, errorMsg string) sdk.Error {
+	return sdk.NewError(codespace, CodeInvalidDescription, errorMsg)
 }
 
 func ErrInvalidProposalType(codespace sdk.CodespaceType, proposalType ProposalKind) sdk.Error {

x/gov/msgs.go

@@ -11,6 +11,9 @@ const (
 	TypeMsgDeposit        = "deposit"
 	TypeMsgVote           = "vote"
 	TypeMsgSubmitProposal = "submit_proposal"
+
+	MaxDescriptionLength int = 5000
+	MaxTitleLength       int = 140
 )
 
 var _, _, _ sdk.Msg = MsgSubmitProposal{}, MsgDeposit{}, MsgVote{}
@@ -42,10 +45,16 @@ func (msg MsgSubmitProposal) Type() string  { return TypeMsgSubmitProposal }
 // Implements Msg.
 func (msg MsgSubmitProposal) ValidateBasic() sdk.Error {
 	if len(msg.Title) == 0 {
-		return ErrInvalidTitle(DefaultCodespace, msg.Title) // TODO: Proper Error
+		return ErrInvalidTitle(DefaultCodespace, "No title present in proposal")
+	}
+	if len(msg.Title) > MaxTitleLength {
+		return ErrInvalidTitle(DefaultCodespace, fmt.Sprintf("Proposal title is longer than max length of %d", MaxTitleLength))
 	}
 	if len(msg.Description) == 0 {
-		return ErrInvalidDescription(DefaultCodespace, msg.Description) // TODO: Proper Error
+		return ErrInvalidDescription(DefaultCodespace, "No description present in proposal")
+	}
+	if len(msg.Description) > MaxDescriptionLength {
+		return ErrInvalidDescription(DefaultCodespace, fmt.Sprintf("Proposal description is longer than max length of %d", MaxDescriptionLength))
 	}
 	if !validProposalType(msg.ProposalType) {
 		return ErrInvalidProposalType(DefaultCodespace, msg.ProposalType)

x/gov/msgs_test.go

@@ -1,6 +1,7 @@
 package gov
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -40,6 +41,8 @@ func TestMsgSubmitProposal(t *testing.T) {
 		{"Test Proposal", "the purpose of this proposal is to test", ProposalTypeText, sdk.AccAddress{}, coinsPos, false},
 		{"Test Proposal", "the purpose of this proposal is to test", ProposalTypeText, addrs[0], coinsZero, true},
 		{"Test Proposal", "the purpose of this proposal is to test", ProposalTypeText, addrs[0], coinsMulti, true},
+		{strings.Repeat("#", MaxTitleLength*2), "the purpose of this proposal is to test", ProposalTypeText, addrs[0], coinsMulti, false},
+		{"Test Proposal", strings.Repeat("#", MaxDescriptionLength*2), ProposalTypeText, addrs[0], coinsMulti, false},
 	}
 
 	for i, tc := range tests {