Show the impact of an expense on the active user's balance

.devcontainer/devcontainer.json

@@ -0,0 +1,42 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/javascript-node-postgres
+{
+    "name": "spliit",
+    "dockerComposeFile": "docker-compose.yml",
+    "service": "app",
+
+    // Features to add to the dev container. More info: https://containers.dev/features.
+    // "features": {
+    // 	   "ghcr.io/frntn/devcontainers-features/prism:1": {}
+    // },
+
+    // Use 'postCreateCommand' to run commands after the container is created.
+    "postCreateCommand": "cp container.env.example .env && npm install",
+    "postAttachCommand": {
+    	"npm": "npm run dev"
+    },
+
+    // Use 'forwardPorts' to make a list of ports inside the container available locally.
+    // This can be used to network with other containers or with the host.
+    "forwardPorts": [3000, 5432],
+    "portsAttributes": {
+            "3000": {
+                "label": "App"
+            },
+            "5432": {
+                "label": "PostgreSQL"
+            }
+    },
+
+    // Configure tool-specific properties.
+    "customizations": {
+        "codespaces": {
+            "openFiles": [
+                "README.md"
+            ]
+        }
+    }
+
+    // Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+    // "remoteUser": "root"
+}

.devcontainer/docker-compose.yml

@@ -0,0 +1,33 @@
+version: '3.8'
+
+services:
+  app:
+    image: mcr.microsoft.com/devcontainers/typescript-node:latest
+
+    volumes:
+      - ../..:/workspaces:cached
+
+    # Overrides default command so things don't shut down after the process ends.
+    command: sleep infinity
+
+    # Runs app on the same network as the database container, allows "forwardPorts" in devcontainer.json function.
+    network_mode: service:db
+
+    # Use "forwardPorts" in **devcontainer.json** to forward an app port locally. 
+    # (Adding the "ports" property to this file will not forward from a Codespace.)
+
+  db:
+    image: postgres:latest
+    restart: unless-stopped
+    volumes:
+      - postgres-data:/var/lib/postgresql/data
+    environment:
+      POSTGRES_PASSWORD: 1234
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+
+    # Add "forwardPorts": ["5432"] to **devcontainer.json** to forward PostgreSQL locally.
+    # (Adding the "ports" property to this file will not forward from a Codespace.)
+
+volumes:
+  postgres-data:

next.config.js

@@ -23,6 +23,12 @@ const nextConfig = {
   images: {
     remotePatterns
   },
+  // Required to run in a codespace (see https://github.com/vercel/next.js/issues/58019)
+  experimental: {
+    serverActions: {
+        allowedOrigins: ['localhost:3000'],
+    },
+},
 }
 
 module.exports = nextConfig

src/app/groups/[groupId]/expenses/active-user-balance.tsx

@@ -0,0 +1,43 @@
+'use client'
+import { Money } from '@/components/money'
+import { getBalances } from '@/lib/balances'
+import { useActiveUser } from '@/lib/hooks'
+
+type Props = {
+  groupId: string
+  currency: string
+  expense: Parameters<typeof getBalances>[0][number]
+}
+
+export function ActiveUserBalance({ groupId, currency, expense }: Props) {
+  const activeUserId = useActiveUser(groupId)
+  if (activeUserId === null || activeUserId === '' || activeUserId === 'None') {
+    return null
+  }
+
+  const balances = getBalances([expense])
+  let fmtBalance = <>You are not involved</>
+  if (Object.hasOwn(balances, activeUserId)) {
+    const balance = balances[activeUserId]
+    let balanceDetail = <></>
+    if (balance.paid > 0 && balance.paidFor > 0) {
+      balanceDetail = (
+        <>
+          {' ('}
+          <Money {...{ currency, amount: balance.paid }} />
+          {' - '}
+          <Money {...{ currency, amount: balance.paidFor }} />
+          {')'}
+        </>
+      )
+    }
+    fmtBalance = (
+      <>
+        Your balance:{' '}
+        <Money {...{ currency, amount: balance.total }} bold colored />
+        {balanceDetail}
+      </>
+    )
+  }
+  return <div className="text-xs text-muted-foreground">{fmtBalance}</div>
+}

src/app/groups/[groupId]/expenses/expense-list.tsx

@@ -1,4 +1,5 @@
 'use client'
+import { ActiveUserBalance } from '@/app/groups/[groupId]/expenses/active-user-balance'
 import { CategoryIcon } from '@/app/groups/[groupId]/expenses/category-icon'
 import { Button } from '@/components/ui/button'
 import { SearchBar } from '@/components/ui/search-bar'
@@ -151,6 +152,9 @@ export function ExpenseList({
                       </Fragment>
                     ))}
                   </div>
+                  <div className="text-xs text-muted-foreground">
+                    <ActiveUserBalance {...{ groupId, currency, expense }} />
+                  </div>
                 </div>
                 <div className="flex flex-col justify-between items-end">
                   <div

src/components/money.tsx

@@ -0,0 +1,31 @@
+'use client'
+import { cn, formatCurrency } from '@/lib/utils'
+
+type Props = {
+  currency: string
+  amount: number
+  bold?: boolean
+  colored?: boolean
+}
+
+export function Money({
+  currency,
+  amount,
+  bold = false,
+  colored = false,
+}: Props) {
+  return (
+    <span
+      className={cn(
+        colored && amount <= 1
+          ? 'text-red-600'
+          : colored && amount >= 1
+          ? 'text-green-600'
+          : '',
+        bold && 'font-bold',
+      )}
+    >
+      {formatCurrency(currency, amount)}
+    </span>
+  )
+}