chore: Initial code to generate ts code from Noir ABI (#2750)

This is some rough code to generate typescript bindings for a given
abi.json


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---------

Co-authored-by: sirasistant <sirasistant@gmail.com>

yarn-project/noir-compiler/src/index.ts

@@ -11,6 +11,8 @@ export { generateNoirContractInterface } from './contract-interface-gen/noir.js'
 export { generateTypescriptContractInterface } from './contract-interface-gen/typescript.js';
 export { generateAztecAbi };
 
+export * from './noir_artifact.js';
+
 /**
  * Compile Aztec.nr contracts in project path using a nargo binary available in the shell.
  * @param projectPath - Path to project.

yarn-project/noir-compiler/src/noir_artifact.ts

@@ -4,7 +4,7 @@ import { ABIParameter, ABIType, DebugFileMap, DebugInfo } from '@aztec/foundatio
 type NoirFunctionType = 'Open' | 'Secret' | 'Unconstrained';
 
 /** The ABI of an Aztec.nr function. */
-interface NoirFunctionAbi {
+export interface NoirFunctionAbi {
   /** The parameters of the function. */
   parameters: ABIParameter[];
   /** The witness indices of the parameters. Indexed by parameter name. */
@@ -47,6 +47,22 @@ export interface NoirCompiledContract {
   functions: NoirFunctionEntry[];
 }
 
+/**
+ * The compilation result of an Aztec.nr contract.
+ */
+export interface NoirCompiledCircuit {
+  /** The hash of the circuit. */
+  hash: number;
+  /** Compilation backend. */
+  backend: string;
+  /**
+   * The ABI of the function.
+   */
+  abi: NoirFunctionAbi;
+  /** The bytecode of the circuit in base64. */
+  bytecode: string;
+}
+
 /**
  * The debug metadata of an Aztec.nr contract.
  */

yarn-project/noir-private-kernel/.gitignore

@@ -1,2 +1,3 @@
-dist
-.yarn
+proofs/
+Prover.toml
+Verifier.toml

yarn-project/noir-private-kernel/.prettierignore

@@ -1,2 +1,3 @@
 src/crates
-src/target
+src/target
+src/types

yarn-project/noir-private-kernel/package.json

@@ -12,6 +12,8 @@
     "clean": "rm -rf ./dest .tsbuildinfo",
     "formatting": "run -T prettier --check ./src && run -T eslint ./src",
     "formatting:fix": "run -T prettier -w ./src",
+    "noir:build": "cd src && nargo compile",
+    "noir:types": "yarn ts-node --esm src/scripts/generate_ts_from_abi.ts",
     "test": "NODE_NO_WARNINGS=1 node --experimental-vm-modules $(yarn bin jest) --passWithNoTests"
   },
   "inherits": [
@@ -26,7 +28,9 @@
     "rootDir": "./src"
   },
   "dependencies": {
+    "@aztec/circuits.js": "workspace:^",
     "@aztec/foundation": "workspace:^",
+    "@aztec/noir-compiler": "workspace:^",
     "@noir-lang/acvm_js": "^0.28.0",
     "@noir-lang/backend_barretenberg": "^0.7.10",
     "@noir-lang/noir_js": "^0.16.0",

yarn-project/noir-private-kernel/src/index.ts

@@ -1,10 +1,11 @@
+import { NoirCompiledCircuit } from '@aztec/noir-compiler';
+
 import PrivateKernelInitJson from './target/private_kernel_init.json' assert { type: 'json' };
 import PrivateKernelInnerJson from './target/private_kernel_inner.json' assert { type: 'json' };
 import PrivateKernelOrderingJson from './target/private_kernel_ordering.json' assert { type: 'json' };
 
-// TODO add types for noir circuit artifacts
-export const PrivateKernelInitArtifact = PrivateKernelInitJson;
+export const PrivateKernelInitArtifact = PrivateKernelInitJson as NoirCompiledCircuit;
 
-export const PrivateKernelInnerArtifact = PrivateKernelInnerJson;
+export const PrivateKernelInnerArtifact = PrivateKernelInnerJson as NoirCompiledCircuit;
 
-export const PrivateKernelOrderingArtifact = PrivateKernelOrderingJson;
+export const PrivateKernelOrderingArtifact = PrivateKernelOrderingJson as NoirCompiledCircuit;

yarn-project/noir-private-kernel/src/scripts/generate_ts_from_abi.ts

@@ -0,0 +1,202 @@
+import { ABIType } from '@aztec/foundation/abi';
+import { createConsoleLogger } from '@aztec/foundation/log';
+import { NoirCompiledCircuit, NoirFunctionAbi } from '@aztec/noir-compiler';
+
+import fs from 'fs/promises';
+
+const log = createConsoleLogger('aztec:noir-contracts');
+
+/**
+ * Keep track off all of the Noir primitive types that were used.
+ * Most of these will not have a 1-1 definition in TypeScript,
+ * so we will need to generate type aliases for them.
+ *
+ * We want to generate type aliases
+ * for specific types that are used in the ABI.
+ *
+ * For example:
+ * - If `Field` is used we want to alias that
+ * with `number`.
+ * - If `u32` is used we want to alias that with `number` too.
+ */
+type PrimitiveTypesUsed = {
+  /**
+   * The name of the type alias that we will generate.
+   */
+  aliasName: string;
+  /**
+   * The TypeScript type that we will alias to.
+   */
+  tsType: string;
+};
+
+const noirPrimitiveTypesToTsTypes = new Map<string, PrimitiveTypesUsed>();
+
+/**
+ * Typescript does not allow us to check for equality of non-primitive types
+ * easily, so we create a addIfUnique function that will only add an item
+ * to the map if it is not already there by using JSON.stringify.
+ * @param item - The item to add to the map.
+ */
+function addIfUnique(item: PrimitiveTypesUsed) {
+  const key = JSON.stringify(item);
+  if (!noirPrimitiveTypesToTsTypes.has(key)) {
+    noirPrimitiveTypesToTsTypes.set(key, item);
+  }
+}
+
+/**
+ * Converts an ABI type to a TypeScript type.
+ * @param type - The ABI type to convert.
+ * @returns The typescript code to define the type.
+ */
+function abiTypeToTs(type: ABIType): string {
+  switch (type.kind) {
+    case 'integer': {
+      let tsIntType = '';
+      if (type.sign === 'signed') {
+        tsIntType = `i${type.width}`;
+      } else {
+        tsIntType = `u${type.width}`;
+      }
+      addIfUnique({ aliasName: tsIntType, tsType: 'number' });
+      return tsIntType;
+    }
+    case 'boolean':
+      return `boolean`;
+    case 'array':
+      return `${abiTypeToTs(type.type)}[]`;
+    case 'struct':
+      return getLastComponentOfPath(type.path);
+    case 'field':
+      addIfUnique({ aliasName: 'Field', tsType: 'number' });
+      return 'Field';
+    default:
+      throw new Error(`Unknown ABI type ${type}`);
+  }
+}
+
+/**
+ * Returns the last component of a path, e.g. "foo::bar::baz" -\> "baz"
+ * Note: that if we have a path such as "Baz", we will return "Baz".
+ *
+ * Since these paths corresponds to structs, we can assume that we
+ * cannot have "foo::bar::".
+ *
+ * We also make the assumption that since these paths are coming from
+ * Noir, then we will not have two paths that look like this:
+ * - foo::bar::Baz
+ * - cat::dog::Baz
+ * ie the last component of the path (struct name) is enough to uniquely identify
+ * the whole path.
+ *
+ * TODO: We should double check this assumption when we use type aliases,
+ * I expect that `foo::bar::Baz as Dog` would effectively give `foo::bar::Dog`
+ * @param str - The path to get the last component of.
+ * @returns The last component of the path.
+ */
+function getLastComponentOfPath(str: string): string {
+  const parts = str.split('::');
+  const lastPart = parts[parts.length - 1];
+  return lastPart;
+}
+
+/**
+ * Generates TypeScript interfaces for the structs used in the ABI.
+ * @param type - The ABI type to generate the interface for.
+ * @param output - The set of structs that we have already generated bindings for.
+ * @returns The TypeScript code to define the struct.
+ */
+function generateStructInterfaces(type: ABIType, output: Set<string>): string {
+  let result = '';
+
+  // Edge case to handle the array of structs case.
+  if (type.kind === 'array' && type.type.kind === 'struct' && !output.has(getLastComponentOfPath(type.type.path))) {
+    result += generateStructInterfaces(type.type, output);
+  }
+  if (type.kind !== 'struct') return result;
+
+  // List of structs encountered while viewing this type that we need to generate
+  // bindings for.
+  const typesEncountered = new Set<ABIType>();
+
+  // Codegen the struct and then its fields, so that the structs fields
+  // are defined before the struct itself.
+  let codeGeneratedStruct = '';
+  let codeGeneratedStructFields = '';
+
+  const structName = getLastComponentOfPath(type.path);
+  if (!output.has(structName)) {
+    codeGeneratedStruct += `interface ${structName} {\n`;
+    for (const field of type.fields) {
+      codeGeneratedStruct += `  ${field.name}: ${abiTypeToTs(field.type)};\n`;
+      typesEncountered.add(field.type);
+    }
+    codeGeneratedStruct += `}\n\n`;
+    output.add(structName);
+
+    // Generate code for the encountered structs in the field above
+    for (const type of typesEncountered) {
+      codeGeneratedStructFields += generateStructInterfaces(type, output);
+    }
+  }
+
+  return codeGeneratedStructFields + '\n' + codeGeneratedStruct;
+}
+
+/**
+ * Generates a TypeScript interface for the ABI.
+ * @param abiObj - The ABI to generate the interface for.
+ * @returns The TypeScript code to define the interface.
+ */
+function generateTsInterface(abiObj: NoirFunctionAbi): string {
+  let result = ``;
+  const outputStructs = new Set<string>();
+
+  // Define structs for composite types
+  for (const param of abiObj.parameters) {
+    result += generateStructInterfaces(param.type, outputStructs);
+  }
+
+  // Generating Return type, if it exists
+  //
+  if (abiObj.return_type != null) {
+    result += generateStructInterfaces(abiObj.return_type, outputStructs);
+    result += `export interface ReturnType {\n`;
+    result += `  value: ${abiTypeToTs(abiObj.return_type)};\n`;
+    result += `}\n\n`;
+  }
+
+  // Generating Input type
+  result += 'export interface InputType {\n';
+  for (const param of abiObj.parameters) {
+    result += `  ${param.name}: ${abiTypeToTs(param.type)};\n`;
+  }
+  result += '}';
+
+  // Add the primitive Noir types that do not have a 1-1 mapping to TypeScript.
+  let primitiveTypeAliases = '';
+  for (const [, value] of noirPrimitiveTypesToTsTypes) {
+    primitiveTypeAliases += `\ntype ${value.aliasName} = ${value.tsType};`;
+  }
+
+  return `/* Autogenerated file, do not edit! */\n\n/* eslint-disable */\n` + primitiveTypeAliases + '\n' + result;
+}
+
+const circuits = ['private_kernel_init', 'private_kernel_inner', 'private_kernel_ordering'];
+
+const main = async () => {
+  for (const circuit of circuits) {
+    const rawData = await fs.readFile(`./src/target/${circuit}.json`, 'utf-8');
+    const abiObj: NoirCompiledCircuit = JSON.parse(rawData);
+    const generatedInterface = generateTsInterface(abiObj.abi);
+    await fs.writeFile(`./src/types/${circuit}_types.ts`, generatedInterface);
+  }
+};
+
+try {
+  await main();
+} catch (err: unknown) {
+  log(`Error generating types ${err}`);
+  process.exit(1);
+}