Implement JSON description objects

Author: jasonpaulos

.eslintrc.js

@@ -23,6 +23,7 @@ module.exports = {
         ts: 'never',
       },
     ],
+    'import/prefer-default-export': 'off',
     'lines-between-class-members': [
       'error',
       'always',

src/abi/contract.ts

@@ -0,0 +1,21 @@
+import { ABIMethod, ABIMethodParams } from './method';
+
+export interface ABIContractParams {
+  name: string;
+  // eslint-disable-next-line camelcase
+  app_id: number;
+  methods: ABIMethodParams[];
+}
+
+export class ABIContract {
+  public readonly name: string;
+  // eslint-disable-next-line camelcase
+  public readonly app_id: number;
+  public readonly methods: ABIMethod[];
+
+  constructor(params: ABIContractParams) {
+    this.name = params.name;
+    this.app_id = params.app_id;
+    this.methods = params.methods.map((method) => new ABIMethod(method));
+  }
+}

src/abi/index.ts

@@ -0,0 +1,4 @@
+export * from './abi_type';
+export * from './contract';
+export * from './interface';
+export * from './method';

src/abi/interface.ts

@@ -0,0 +1,16 @@
+import { ABIMethod, ABIMethodParams } from './method';
+
+export interface ABIInterfaceParams {
+  name: string;
+  methods: ABIMethodParams[];
+}
+
+export class ABIInterface {
+  public readonly name: string;
+  public readonly methods: ABIMethod[];
+
+  constructor(params: ABIInterfaceParams) {
+    this.name = params.name;
+    this.methods = params.methods.map((method) => new ABIMethod(method));
+  }
+}

src/abi/method.ts

@@ -0,0 +1,85 @@
+import { genericHash } from '../nacl/naclWrappers';
+import { ABIType, ABITupleType } from './abi_type';
+
+const transactionTypes = ['pay', 'keyreg', 'acfg', 'axfer', 'afrz', 'appl'];
+
+function parseMethodSignature(
+  signature: string
+): { name: string; args: string[]; returns: string } {
+  const argsStart = signature.indexOf('(');
+  const argsEnd = signature.lastIndexOf(')');
+
+  if (argsStart === -1 || argsEnd === -1) {
+    throw new Error(`Invalid method signature: ${signature}`);
+  }
+
+  return {
+    name: signature.slice(argsStart),
+    args: ABITupleType.parseTupleContent(
+      signature.slice(argsStart + 1, argsEnd)
+    ),
+    returns: signature.slice(argsEnd + 1),
+  };
+}
+
+export interface ABIMethodParams {
+  name: string;
+  desc?: string;
+  args: Array<{ name?: string; type: string; desc?: string }>;
+  returns?: { type: string; desc?: string };
+}
+
+export class ABIMethod {
+  public readonly name: string;
+  public readonly desc?: string;
+  public readonly args: Array<{ name?: string; type: string; desc?: string }>;
+  public readonly returns?: { type: string; desc?: string };
+
+  constructor(params: ABIMethodParams) {
+    this.name = params.name;
+    this.desc = params.desc;
+    this.args = params.args;
+    this.returns = params.returns;
+  }
+
+  getSignature(): string {
+    const args = this.args.map((arg) => arg.type).join(',');
+    const returns = this.returns ? this.returns.type : 'void';
+    return `${this.name}(${args})${returns}`;
+  }
+
+  getSelector(): Uint8Array {
+    const hash = genericHash(this.getSignature());
+    return new Uint8Array(hash.slice(0, 4));
+  }
+
+  txnCount(): number {
+    let count = 1;
+    for (const arg of this.args) {
+      if (transactionTypes.includes(arg.type)) {
+        count += 1;
+      }
+    }
+    return count;
+  }
+
+  static fromSignature(signature: string): ABIMethod {
+    const { name, args, returns } = parseMethodSignature(signature);
+
+    // ensure each arg and return type is valid
+    args.forEach((arg) => {
+      if (!transactionTypes.includes(arg)) {
+        ABIType.from(arg);
+      }
+    });
+    if (returns !== 'void') {
+      ABIType.from(returns);
+    }
+
+    return new ABIMethod({
+      name,
+      args: args.map((arg) => ({ type: arg })),
+      returns: returns === 'void' ? undefined : { type: returns },
+    });
+  }
+}

src/main.ts

@@ -165,4 +165,4 @@ export const LogicTemplates = LogicTemplatesCommonJSExport.default;
 export * from './makeTxn';
 export * from './transaction';
 export * from './types';
-export * from './abi/abi_type';
+export * from './abi';