Sqwid marketplace processor

Squid for the Reef Chain Sqwid marketplace.

This project has been created with the Reef EVM event processor template.

Quickstart

• Create a .env file with the contents of .env.sample.

• Start Docker and run the following commands:

# 1. Install dependencies
npm install

# 2. Compile typescript files
make build

# 3. Start target Postgres database and detach
#    DB will be available at localhost:23799/evm_events
make up

# 4. Start the processor
make process

# 5. In a separate terminal, start graphql server
#    GraphQL API will be available at http://localhost:4350/graphql
make serve

# 6. Stop and destroy target Postgres database
make down

Dev flow

1. Define database schema

Delete migration files from db/migrations directory and define the schema of the target database via schema.graphql file, replacing the sample definition. Schema definition consists of regular graphql type declarations annotated with custom directives. Full description of schema.graphql dialect is available here.

2. Generate TypeORM classes

Mapping developers use TypeORM EntityManager to interact with target database during data processing. All necessary entity classes are generated by the squid framework from schema.graphql. This is done by running the following command:

make codegen

3. Import ABI contract and generate interfaces to decode events

It is necessary to import the respective ABI definition to decode EVM logs.

Delete all the contents in src/abi and insert the JSON ABI definition of the contract to index.

To generate a type-safe facade class to decode EVM logs execute the following command:

npx squid-evm-typegen src/abi src/abi/{YOUR_CONTRACT_NAME}.json

And replace the following code in generated the generated abi.support.ts file:

let result = await this._chain.client.call('eth_call', [
      { to: this.address, data },
      '0x' + this.blockHeight.toString(16)
])

by

let result = await this._chain.client.call('evm_call', [
      {to: this.address, data, from: undefined, storageLimit: 0}
])

Project conventions

Squid tools assume a certain project layout.

• All compiled js files must reside in lib and all TypeScript sources in src. The layout of lib must reflect src.
• All TypeORM classes must be exported by src/model/index.ts (lib/model module).
• Database schema must be defined in schema.graphql.
• Database migrations must reside in db/migrations and must be plain js files.
• sqd(1) and squid-*(1) executables consult .env file for a number of environment variables.

Graphql server extensions

It is possible to extend squid-graphql-server(1) with custom type-graphql resolvers and to add request validation. More details will be added later.

Deployment

Deploy a Squid

• To deploy a Squid execute sqd deploy -m <path_to_manifest_file>.