feat: added getAddressAtIndex method and API

.envrc

@@ -0,0 +1,7 @@
+if [[ $(type -t use_flake) != function ]]; then
+  echo "ERROR: use_flake function missing."
+  echo "Please update direnv to v2.30.0 or later."
+  exit 1
+fi
+
+use flake

.gitignore

@@ -24,3 +24,5 @@ coverage
 
 # fcm account config
 **/fcm.config.json
+
+.direnv

README.md

@@ -207,3 +207,16 @@ Sometimes, jest will use old cached js files, even after you modified the typesc
 ## Standard Operating Procedures
 
 Check it in [docs/SOP.md](docs/SOP.md)
+
+
+## Nix flakes
+
+## Using this project
+
+This project uses [Nix](https://nixos.org/) with [direnv](https://direnv.net/) to help with dependencies, including Node.js. To get started, you need to have Nix and direnv installed.
+
+1. Install [Nix](https://nixos.org/download.html) and [Direnv](https://direnv.net/docs/installation.html).
+2. Enable flake support in Nix: `nix-env -iA nixpkgs.nixUnstable`
+3. Allow direnv to work in your shell by running `direnv allow`
+
+Now, every time you enter the project directory, direnv will automatically activate the environment from flake.nix, including the specific version of Node.js specified there. When you leave the directory, it will deactivate. This ensures a consistent and isolated environment per project.

db/migrations/20230601151507-address_index_idx.js

@@ -0,0 +1,17 @@
+'use strict';
+
+module.exports = {
+  up: async (queryInterface) => {
+    await queryInterface.addIndex(
+      'address',
+      ['index'], {
+        name: 'address_index_idx',
+        fields: 'index',
+      },
+    );
+  },
+
+  down: async (queryInterface) => {
+    await queryInterface.removeIndex('address', 'address_index_idx');
+  },
+};

flake.nix

@@ -0,0 +1,39 @@
+/*
+This flake.nix file creates a virtual environment with the desired dependencies 
+in a reproducible way using Nix and Nix flakes (https://nixos.wiki/wiki/Flakes)
+
+Flakes are a feature in Nix that allows you to specify the dependencies of your
+project in a declarative and reproducible manner. It allows for better isolation,
+reproducibility, and more reliable upgrades.
+
+`direnv` is an environment switcher for the shell. It knows how to hook into 
+multiple shells (like bash, zsh, fish, etc...) to load or unload environment
+variables depending on the current directory. This allows project-specific
+environment variables without cluttering the "~/.profile" file.
+
+This flake file creates a shell with nodejs v14.x installed and should work
+on macOs, linux and windows
+*/
+{
+  description = "Flake that installs Node.js 14.x via direnv";
+
+  inputs.devshell.url = "github:numtide/devshell";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, flake-utils, devshell, nixpkgs }:
+
+    flake-utils.lib.eachDefaultSystem (system: {
+      devShell =
+        let pkgs = import nixpkgs {
+          inherit system;
+
+          overlays = [ devshell.overlay ];
+        };
+        in
+        pkgs.devshell.mkShell {
+          packages = with pkgs; [
+            nodejs-14_x
+          ];
+        };
+    });
+}

serverless.yml

@@ -314,6 +314,10 @@ functions:
           method: get
           cors: true
           authorizer: ${self:custom.authorizer.walletBearer}
+          request:
+            parameters:
+              paths:
+                index: false
     warmup:
       walletWarmer:
         enabled: true

src/api/addresses.ts

@@ -7,15 +7,16 @@
 
 import 'source-map-support/register';
 
-import Joi from 'joi';
+import Joi, { ValidationError } from 'joi';
 import { APIGatewayProxyHandler } from 'aws-lambda';
 import { ApiError } from '@src/api/errors';
 import { closeDbAndGetError, warmupMiddleware } from '@src/api/utils';
 import {
   getWallet,
   getWalletAddresses,
+  getAddressAtIndex as dbGetAddressAtIndex,
 } from '@src/db';
-import { AddressInfo } from '@src/types';
+import { AddressInfo, AddressAtIndexRequest } from '@src/types';
 import { closeDbConnection, getDbConnection } from '@src/utils';
 import { walletIdProxyHandler } from '@src/commons';
 import middy from '@middy/core';
@@ -32,6 +33,19 @@ const checkMineBodySchema = Joi.object({
     .required(),
 });
 
+class AddressAtIndexValidator {
+  static readonly bodySchema = Joi.object({
+    index: Joi.number().min(0).optional(),
+  });
+
+  static validate(payload: unknown): { value: AddressAtIndexRequest, error: ValidationError} {
+    return AddressAtIndexValidator.bodySchema.validate(payload, {
+      abortEarly: false, // We want it to return all the errors not only the first
+      convert: true, // We need to convert as parameters are sent on the QueryString
+    }) as { value: AddressAtIndexRequest, error: ValidationError };
+  }
+}
+
 /*
  * Check if a list of addresses belong to the caller wallet
  *
@@ -93,27 +107,66 @@ export const checkMine: APIGatewayProxyHandler = middy(walletIdProxyHandler(asyn
 })).use(cors());
 
 /*
- * Get the addresses of a wallet
+ * Get the addresses of a wallet, allowing an index filter
+ * Notice: If the index filter is passed, it will only find addresses
+ * that are already in our database, this will not derive new addresses
  *
  * This lambda is called by API Gateway on GET /addresses
  */
-export const get: APIGatewayProxyHandler = middy(walletIdProxyHandler(async (walletId) => {
-  const status = await getWallet(mysql, walletId);
+export const get: APIGatewayProxyHandler = middy(
+  walletIdProxyHandler(async (walletId, event) => {
+    const status = await getWallet(mysql, walletId);
 
-  if (!status) {
-    return closeDbAndGetError(mysql, ApiError.WALLET_NOT_FOUND);
-  }
-  if (!status.readyAt) {
-    return closeDbAndGetError(mysql, ApiError.WALLET_NOT_READY);
-  }
+    if (!status) {
+      return closeDbAndGetError(mysql, ApiError.WALLET_NOT_FOUND);
+    }
 
-  const addresses = await getWalletAddresses(mysql, walletId);
+    if (!status.readyAt) {
+      return closeDbAndGetError(mysql, ApiError.WALLET_NOT_READY);
+    }
 
-  await closeDbConnection(mysql);
+    const { value: body, error } = AddressAtIndexValidator.validate(event.pathParameters);
 
-  return {
-    statusCode: 200,
-    body: JSON.stringify({ success: true, addresses }),
-  };
-})).use(cors())
+    if (error) {
+      const details = error.details.map((err) => ({
+        message: err.message,
+        path: err.path,
+      }));
+
+      return closeDbAndGetError(mysql, ApiError.INVALID_PAYLOAD, { details });
+    }
+
+    let response = null;
+
+    if ('index' in body) {
+      const address: AddressInfo | null = await dbGetAddressAtIndex(mysql, walletId, body.index);
+
+      if (!address) {
+        return closeDbAndGetError(mysql, ApiError.ADDRESS_NOT_FOUND);
+      }
+
+      response = {
+        statusCode: 200,
+        body: JSON.stringify({
+          success: true,
+          addresses: [address],
+        }),
+      };
+    } else {
+      // Searching for multiple addresses
+      const addresses = await getWalletAddresses(mysql, walletId);
+      response = {
+        statusCode: 200,
+        body: JSON.stringify({
+          success: true,
+          addresses,
+        }),
+      };
+    }
+
+    await closeDbConnection(mysql);
+
+    return response;
+  }),
+).use(cors())
   .use(warmupMiddleware());

src/api/errors.ts

@@ -30,6 +30,7 @@ export enum ApiError {
   WALLET_ALREADY_LOADED = 'wallet-already-loaded',
   WALLET_MAX_RETRIES = 'wallet-max-retries',
   ADDRESS_NOT_IN_WALLET = 'address-not-in-wallet',
+  ADDRESS_NOT_FOUND = 'address-not-found',
   TX_OUTPUT_NOT_IN_WALLET = 'tx-output-not-in-wallet',
   TOKEN_NOT_FOUND = 'token-not-found',
   FORBIDDEN = 'forbidden',

src/api/utils.ts

@@ -53,6 +53,7 @@ export const STATUS_CODE_TABLE = {
   [ApiError.TOKEN_NOT_FOUND]: 404,
   [ApiError.DEVICE_NOT_FOUND]: 404,
   [ApiError.TX_NOT_FOUND]: 404,
+  [ApiError.ADDRESS_NOT_FOUND]: 404,
 };
 
 /**

src/db/index.ts

@@ -3157,3 +3157,38 @@ export const getUnsentTxProposals = async (
 
   return result.map((row) => row.id);
 };
+
+/**
+ * Gets a specific address from an index and a walletId
+ *
+ * @param mysql - Database connection
+ * @param walletId - The wallet id to search for
+ * @param index - The address index to search for
+ *
+ * @returns An object containing the address, its index and the number of transactions
+ */
+export const getAddressAtIndex = async (
+  mysql: ServerlessMysql,
+  walletId: string,
+  index: number,
+): Promise<AddressInfo | null> => {
+  const addresses = await mysql.query<AddressInfo[]>(
+    `
+    SELECT \`address\`, \`index\`, \`transactions\`
+      FROM \`address\` pd
+     WHERE \`index\` = ?
+       AND \`wallet_id\` = ?
+     LIMIT 1`,
+    [walletId, index],
+  );
+
+  if (addresses.length <= 0) {
+    return null;
+  }
+
+  return {
+    address: addresses[0].address as string,
+    index: addresses[0].index as number,
+    transactions: addresses[0].transactions as number,
+  } as AddressInfo;
+};

src/types.ts

@@ -709,6 +709,10 @@ export interface PushDelete {
   deviceId: string,
 }
 
+export interface AddressAtIndexRequest {
+  index?: number,
+}
+
 export interface TxByIdRequest {
   txId: string,
 }