initial commit

.env

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+DATABASE_HOST=localhost
+DATABASE_PORT=5432
+DATABASE_TEST_PORT=5433
+DATABASE_USERNAME=user
+DATABASE_PASSWORD=pwd
+DATABASE_NAME=database
+MIGRATIONS_RUN=true
+NODE_ENV=development

.gitignore

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+node_modules
+dist

.vscode/settings.json

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+{
+    "editor.formatOnSave": true,
+    "typescript.preferences.importModuleSpecifier": "relative",
+    "editor.codeActionsOnSave": [
+      "source.fixAll",
+      "source.organizeImports",
+      "source.addMissingImports"
+    ],
+  }
+

README.md

@@ -1,2 +1,94 @@
-# public-hiring-test
-Technical tests for hiring software engineering @Greenly
+# How to use
+
+Stack: NestJs + TypeORM + Postgres
+
+## Requirements
+
+- Docker / Docker Compose
+- Node.js 18
+
+## Installation
+
+```bash
+$ yarn
+```
+
+## Running the app
+
+First you need to start, migrate and seed the db :
+
+```bash
+$ yarn init-project
+```
+
+you can then start the server:
+
+```bash
+# development
+$ yarn start
+
+# watch mode
+$ yarn start:dev
+```
+
+## Test
+
+To run unit tests:
+
+```bash
+# unit tests
+$ yarn test
+
+# e2e tests
+$ yarn test:e2e
+
+# test coverage
+$ yarn test:cov
+```
+
+## Database Migration
+
+When the data schema is updated, the database needs to be synchronised with the code. This is done by creating a migration with Typeorm using the following command:
+
+```bash
+migrationName=<name> yarn migration:generate
+```
+
+##################################################################################################################################
+
+# Hiring Test
+
+##################################################################################################################################
+
+When working on the following exercise, in addition to answering the product need, to give particular attention to the following points:
+
+- Readability
+- Maintainability
+- Unit testing
+- Handling of corner cases
+- Error-handling
+
+We want to compute the Agrybalise carbonfootprint of a foodproduct (e.g.: a hamCheesePizza) that we characterize by its ingredients as shown below
+
+```js
+const hamCheesePizza = {
+  ingredients: [
+    { name: "ham", quantity: 0.1, unit: "kg" },
+    { name: "cheese", quantity: 0.15, unit: "kg" },
+    { name: "tomato", quantity: 0.4, unit: "kg" },
+    { name: "floor", quantity: 0.7, unit: "kg" },
+    { name: "oliveOil", quantity: 0.3, unit: "kg" },
+  ],
+};
+```
+
+The calculation of the Agrybalise carbon footprint can be described as below:
+
+- The Agrybalise carbon footprint of one ingredient is obtained by multiplying the quantity of the ingredient by the emission of a matching emission factor (same name and same unit).
+- The carbon footprint of the food product is then obtained by summing the carbon footprint of all ingredients.
+- If the carbon footprint of one ingredient cannot be calculated, then the carbon footprint of the whole product is set to null.
+
+The tasks of this exercice are as follows:
+1/ Implement the carbon footprint calculation of a product and persist the results in database.
+2/ Implement a GET endpoint to retrieve the result.
+3/ Implement a POST endpoint to trigger the calculation and the saving in the database.

config/dataSource.ts

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+import { registerAs } from "@nestjs/config";
+import { config as dotenvConfig } from "dotenv";
+import { join } from "path";
+import { DataSource, DataSourceOptions } from "typeorm";
+
+dotenvConfig({ path: ".env" });
+
+const dataSourceOptions: DataSourceOptions = {
+  type: "postgres",
+  port: parseInt(
+    `${process.env.NODE_ENV === "test" ? process.env.DATABASE_TEST_PORT : process.env.DATABASE_PORT}`
+  ),
+  username: process.env.DATABASE_USERNAME,
+  password: process.env.DATABASE_PASSWORD,
+  database: process.env.DATABASE_NAME,
+  synchronize: false,
+  logging: false,
+  entities: [join(__dirname, "../src/**/*.entity.{js,ts}")],
+  migrations: [join(__dirname, "../migrations", "*.*")],
+  migrationsTableName: "migrations",
+  migrationsRun: process.env.MIGRATIONS_RUN === "true",
+};
+
+export const typeorm = registerAs("typeorm", () => dataSourceOptions);
+
+export class GreenlyDataSource {
+  private static dataSource: DataSource;
+  private static testDataSource: DataSource;
+
+  public static getInstance() {
+    if (process.env.NODE_ENV === "test") {
+      if (this.testDataSource) {
+        console.log(`testDataSource already set for ${process.env.NODE_ENV}`);
+        return this.testDataSource;
+      }
+      this.testDataSource = new DataSource(dataSourceOptions);
+
+      return this.testDataSource;
+    }
+    if (this.dataSource) {
+      console.log(`dataSource already set for ${process.env.NODE_ENV}`);
+      return this.dataSource;
+    }
+    this.dataSource = new DataSource(dataSourceOptions);
+
+    return this.dataSource;
+  }
+
+  public static async cleanDatabase(): Promise<void> {
+    try {
+      const entities = dataSource.entityMetadatas;
+      const tableNames = entities
+        .map((entity) => `"${entity.tableName}"`)
+        .join(", ");
+
+      await dataSource.query(`TRUNCATE ${tableNames} CASCADE;`);
+    } catch (error) {
+      throw new Error(`ERROR: Cleaning test database: ${error}`);
+    }
+  }
+}
+
+export const dataSource = GreenlyDataSource.getInstance();

docker-compose.yml

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+services:
+  db:
+    image: postgres
+    restart: always
+    environment:
+      POSTGRES_USER: ${DATABASE_USERNAME}
+      POSTGRES_PASSWORD: ${DATABASE_PASSWORD}
+      POSTGRES_DB: ${DATABASE_NAME} 
+    ports:
+      - "${DATABASE_PORT}:5432"
+  db_test:
+    image: postgres
+    restart: always
+    environment:
+      POSTGRES_USER: ${DATABASE_USERNAME}
+      POSTGRES_PASSWORD: ${DATABASE_PASSWORD}
+      POSTGRES_DB: ${DATABASE_NAME}
+      # PGPORT
+    ports:
+      - "${DATABASE_TEST_PORT}:5432"

jest.json

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+{
+  "moduleFileExtensions": ["js", "json", "ts"],
+  "rootDir": "./src",
+  "testEnvironment": "node",
+  "testRegex": ".test.ts",
+  "transform": {
+    "^.+\\.(t|j)s$": "ts-jest"
+  }
+}

migrations/1708367794381-carbonEmissionFactor.ts

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+import { MigrationInterface, QueryRunner } from "typeorm";
+
+export class CarbonEmissionFactor1708367794381 implements MigrationInterface {
+  name = "CarbonEmissionFactor1708367794381";
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `CREATE TABLE "carbon_emission_factors" ("id" SERIAL NOT NULL, "name" character varying NOT NULL, "unit" character varying NOT NULL, "emissionCO2eInKgPerUnit" float NOT NULL, "source" character varying NOT NULL, CONSTRAINT "PK_e6a201ea58a7b4cdec0ca1c0c61" PRIMARY KEY ("id"))`
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`DROP TABLE "carbon_emission_factors"`);
+  }
+}

nest-cli.json

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+{
+  "$schema": "https://json.schemastore.org/nest-cli",
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src",
+  "compilerOptions": {
+    "deleteOutDir": true
+  }
+}

notes.txt

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+## Sources
+to integrate typeorm and generate migrations
+
+https://dev.to/amirfakour/using-typeorm-migration-in-nestjs-with-postgres-database-3c75
+
+
+
+
+Technical 
+
+- Start from a boiler plate with simple database: 
+-postgre /Typeorm/express//jest
+
+```js
+const carbonEmissionFactors = [
+  {
+    Name: "ham",
+    unit: "kg",
+    valueInKgCO2: 0.12,
+    source: "Agrybalise",
+  },
+  {
+    name: cheese,
+    unit: "kg",
+    valueInKgCO2: 0.12,
+    source: "Agrybalise",
+  },
+  {
+    name: tomato,
+    unit: "kg",
+    valueInKgCO2: 0.12,
+    source: "Agrybalise",
+  },
+  {
+    name: oliveOil,
+    unit: l,
+    valueInKgCO2: 0.12,
+    source: "Agrybalise",
+  },
+];
+
+```
+
+
+When working on the following exercise, give particular attention to the following points:
+Readability of your code
+Unit Testing
+Architecture and organization of your functions  
+Handling of corner cases and errors
+Overall performance of your code
+
+1/ Create an endpoint to compute carbonFootprint of food and persist data in database.
+```js
+const hamCheesePizza = {
+  ingredients: [
+    { name: "ham", value: "2", unit: "g" },
+    { name: "cheese", value: "15", unit: "g" },
+    { name: "tomato", value: "4", unit: "g" },
+    { name: "floor", value: "7", unit: "g" },
+    { name: "oliveOil", value: "0.7", unit: "l" },
+  ],
+};
+```
+2/Agrybalise has updated its coefficients and we want to update accordingly our knowledge base. In order to do that, we need to develop and endpoint allowing to update and/or insert new values in our referential of emission factors.
+
+In particular, we want to add these values:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Test Criterion for technical test:
+Problem solving solution: should solve efficiently the problem
+Clean code aspects: readability (naming, architecture), test
+Performance of code & algorithmic
+Knowledge of database
+Error handling & exceptions
+
+Test Criterion for technical test:
+Clarity of explanation of approach and database
+General engineering culture
+Reactivity on advices & inputs
+
+
+
+
+Questions:
+
+
+
+2/ 
+
+Fonction buggé
+
+
+Performance
+
+Asynchronous feature
+Utiliser un ORM
+Rest API
+Base de donnée 
+
+Bonus:
+authentification