cosmos-scavenge

Detailed steps of implementation are described in Cosmos SDK Tutorial. You may go directly to Build app below to build and start the app.

Download and build `scaffold`

mkdir -p ~/work/cosmos-tutorial
cd ~/work/cosmos-tutorial
git clone git@github.com:cosmos/scaffold.git
cd scaffold
make

Generate app and module

cd ~/work/cosmos-tutorial
scaffold app lvl-1 yxuco cosmos-scavenge
cd cosmos-scavenge/x
scaffold module yxuco cosmos-scavenge scavenge
cd .. && go mod tidy

Define messages

Define messages using the generated template x/scavenge/types/msg.go

implement sdk.Msg interface: https://github.com/cosmos/cosmos-sdk/blob/master/types/tx_msg.go
Register messages in x/scavenge/types/codec.go
Create x/scavenge/alias.go to make nested definitions of types and keeper available at module's top level

Define key store and keeper functions

In x/scavenge/types/types.go, define data struct for key store
In x/scavenge/types/key.go, define key prefixes for each key store data
In x/scavenge/keeper/keeper.go, define functions for accessing key store

Implement message handler

Implement handler functions to processe each message and interact with key store.

Edit generated templates in x/scavenge/handler.go
Define event types in x/scavenge/types/events.go (events help client apps to know what happened in a transaction)

Implement querier to query key store

Implement query functions in x/scavenge/keeper/querier.go
Define query types in x/scavenge/types/querier.go

Implement CLI

Implement CLI app to send transaction and query.

Implement functions for creating transactions in x/scavenge/client/cli/tx.go
Implement functions for creating queries in x/scavenge/client/cli/query.go

Make module reusable by any app

Edit x/scavenge/module.go to add bank.Keeper to AppModule struct and NowAppModule function

Use module in app

In app/app.go, follow comments of TODO to change name of appd appcli and add module refs
Change folder name of cmd/appd and cmd/appcli
Edit rootCmd description in cmd/appcli/main.go
Edit rootCmd description in cmd/appd/main.go

Build app

At app root, go mod tidy
Edit Makefile to set appdand appcli
make
Verify executable: scavengeD -h, and scavengeCLI -h

Config and start a node

./init.sh
scavengeD start

Play scavenge

Send transaction to create scavenge:

scavengeCLI tx scavenge createScavenge 69foo "A stick" "What's brown and sticky?" --from me

Send query to verify that the scavenge of the resulting txhash is created:

scavengeCLI q tx <txhash>

Send transaction to commit a solution:

scavengeCLI tx scavenge commitSolution "A stick" --from you

Send query to verify that a solution is committed:

scavengeCLI q scavenge commited "A stick" $(scavengeCLI keys show you -a)

Send transaction to reveal the solution:

scavengeCLI tx scavenge revealSolution "A stick" --from you

Send query to verify that the scavenger account received 69foo coins:

scavengeCLI q account $(scavengeCLI keys show you -a)

Send query to list scavenges and show the solutions:

scavengeCLI q scavenge list
scavengeCLI q scavenge get <solutionHash>

yxuco/cosmos-scavenge