chore(medusa): Improve database loader error handling (#4254)

* chore(medusa): Improve database loader error handling

* Create sharp-melons-doubt.md

* move the database error handling to the utils

* fix unit tests

* tackle feedback

* fix unit tests

packages/utils/src/common/__tests__/handle-postgres-database-error.spec.ts

@@ -0,0 +1,107 @@
+import {
+  DatabaseErrorCode,
+  handlePostgresDatabaseError,
+} from "../handle-postgres-database-error"
+import { EOL } from "os"
+
+describe("handlePostgresDataError", function () {
+  it("should throw a specific message on database does not exists", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: DatabaseErrorCode.databaseDoesNotExist })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual(
+      `The specified PostgreSQL database does not exist. Please create it and try again.${EOL}${error.message}`
+    )
+  })
+
+  it("should throw a specific message on database connection failure", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: DatabaseErrorCode.connectionFailure })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual(
+      `Failed to establish a connection to PostgreSQL. Please ensure the following is true and try again:
+      - You have a PostgreSQL database running
+      - You have passed the correct credentials in medusa-config.js
+      - You have formatted the database connection string correctly. See below:
+      "postgres://[username]:[password]@[host]:[post]/[db_name]" - If there is no password, you can omit it from the connection string
+      ${EOL}
+      ${error.message}`
+    )
+  })
+
+  it("should throw a specific message on database wrong credentials", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: DatabaseErrorCode.wrongCredentials })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual(
+      `The specified credentials does not exists for the specified PostgreSQL database.${EOL}${error.message}`
+    )
+  })
+
+  it("should throw a specific message on database not found", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: DatabaseErrorCode.notFound })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual(
+      `The specified connection string for your PostgreSQL database might have illegal characters. Please check that it only contains allowed characters [a-zA-Z0-9]${EOL}${error.message}`
+    )
+  })
+
+  it("should throw a specific message on database migration missing", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: DatabaseErrorCode.migrationMissing })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual(
+      `Migrations missing. Please run 'medusa migrations run' and try again.`
+    )
+  })
+
+  it("should re throw unhandled error code", function () {
+    const error = new Error("database does not exist")
+    Object.assign(error, { code: "test" })
+
+    let outputError: any
+    try {
+      handlePostgresDatabaseError(error)
+    } catch (e) {
+      outputError = e
+    }
+
+    expect(outputError.message).toEqual("database does not exist")
+  })
+})