Login gains an audit log

A sequence diff. A new audit log records each login, a locked-account branch is added, and the first message is renamed.

     ┌──────┐              ┌──────────┐       ┌──────────────┐  ┌──────────┐  ┌──────────────┐
     │ User │              │ Web App  │       │ Auth Service │  │ Database │  │ + Audit Log  │
     └──────┘              └──────────┘       └──────────────┘  └──────────┘  └──────────────┘
         │                       │                    │               │               │
         │                       │                    │               │               │
         ├ ~ submit credentials ─►                    │               │               │
         │                       ┃                    │               │               │
         │                       ├ check credentials ─►               │               │
         │                       │                    ┃               │               │
         │                       │                    ├─ lookup user ─►               │
         │                       │                    │               ┃               │
         │                       │                    ◄╌ user record ╌┤               │
         │                       │                    ┃               │               │
  ╔══ alt [~ valid] ═════════════╪════════════════════╪═══════════════╪═══════════════╪═══════╗
  ║      │                       ◄╌╌╌╌╌╌╌ ok ╌╌╌╌╌╌╌╌╌┤               │               │       ║
  ║      │                       ┃                    │               │               │       ║
  ║      │                       ┠───────────────── + record login ───┼───────────────▷       ║
  ║      │                       ┃                    │               │               │       ║
  ║      ◄╌╌╌╌╌╌╌ welcome ╌╌╌╌╌╌╌┤                    │               │               │       ║
  ║      ┃                       │                    │               │               │       ║
  ╟╌╌ [invalid] ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╢
  ║      │                       ◄╌╌╌╌╌ denied ╌╌╌╌╌╌╌┤               │               │       ║
  ║      │                       ┃                    │               │               │       ║
  ║      ◄╌╌╌╌╌╌╌╌ error ╌╌╌╌╌╌╌╌┤                    │               │               │       ║
  ║      │                       │                    │               │               │       ║
  ╟╌╌ [+ locked] ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╪╌╌╌╌╌╌╌╢
  ║      │                       ◄╌╌╌╌ + locked ╌╌╌╌╌╌┤               │               │       ║
  ║      │                       ┃                    │               │               │       ║
  ║      ◄╌╌ + account locked ╌╌╌┤                    │               │               │       ║
  ╚══════╪═══════════════════════╪════════════════════╪═══════════════╪═══════════════╪═══════╝
         │                       │                    │               │               │
     ┌──────┐              ┌──────────┐       ┌──────────────┐  ┌──────────┐  ┌──────────────┐
     │ User │              │ Web App  │       │ Auth Service │  │ Database │  │ + Audit Log  │
     └──────┘              └──────────┘       └──────────────┘  └──────────┘  └──────────────┘

sequence-login-v1.json → sequence-login-v2.json
added: actor Audit Log
added: message Web App -> Audit Log "record login"
added: message Auth Service -> Web App "locked"
added: message Web App -> User "account locked"
added: section [locked] of alt
changed: message User -> Web App: label "submit form" → "submit credentials"

The version before the change: User, Web App, Auth Service and Database. — Before

The version after the change: User, Web App, Auth Service, Database and Audit Log. — After

Spec

{
  "type": "sequence",
  "actors": [
    {"id": "user", "label": "User"},
    {"id": "web", "label": "Web App"},
    {"id": "auth", "label": "Auth Service"},
    {"id": "db", "label": "Database", "color": "red"}
  ],
  "interactions": [
    {"from": "user", "to": "web", "label": "submit form"},
    {"from": "web", "to": "auth", "label": "check credentials"},
    {"from": "auth", "to": "db", "label": "lookup user"},
    {"from": "db", "to": "auth", "label": "user record", "style": "dashed"},
    {"from": "auth", "to": "web", "label": "ok", "style": "dashed"},
    {"from": "web", "to": "user", "label": "welcome", "style": "dashed"},
    {"from": "auth", "to": "web", "label": "denied", "style": "dashed"},
    {"from": "web", "to": "user", "label": "error", "style": "dashed"}
  ],
  "fragments": [
    {
      "type": "alt",
      "over": ["user", "web", "auth"],
      "sections": [
        {"label": "valid", "start": 4, "end": 5},
        {"label": "invalid", "start": 6, "end": 7}
      ]
    }
  ]
}

{
  "type": "sequence",
  "actors": [
    {"id": "user", "label": "User"},
    {"id": "web", "label": "Web App"},
    {"id": "auth", "label": "Auth Service"},
    {"id": "db", "label": "Database", "color": "red"},
    {"id": "audit", "label": "Audit Log"}
  ],
  "interactions": [
    {"from": "user", "to": "web", "label": "submit credentials"},
    {"from": "web", "to": "auth", "label": "check credentials"},
    {"from": "auth", "to": "db", "label": "lookup user"},
    {"from": "db", "to": "auth", "label": "user record", "style": "dashed"},
    {"from": "auth", "to": "web", "label": "ok", "style": "dashed"},
    {"from": "web", "to": "audit", "label": "record login", "style": "async"},
    {"from": "web", "to": "user", "label": "welcome", "style": "dashed"},
    {"from": "auth", "to": "web", "label": "denied", "style": "dashed"},
    {"from": "web", "to": "user", "label": "error", "style": "dashed"},
    {"from": "auth", "to": "web", "label": "locked", "style": "dashed"},
    {"from": "web", "to": "user", "label": "account locked", "style": "dashed"}
  ],
  "fragments": [
    {
      "type": "alt",
      "over": ["user", "web", "auth"],
      "sections": [
        {"label": "valid", "start": 4, "end": 6},
        {"label": "invalid", "start": 7, "end": 8},
        {"label": "locked", "start": 9, "end": 10}
      ]
    }
  ]
}

Draw it yourself

diago diff login-change.v1.json login-change.v2.json > login-change.diff.svg

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