prisma validate error - thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value'

Bug description

I have a self-referencing table model in my schema that looks like this:

model Folder {
  id                         String            @db.Char(30) @default(cuid()) @id
  name                   String            @db.MediumText
  childFolders          Folder[]          @relation("ChildToParentFolder")
  parentFolderId     String?           @db.Char(30)
  parentFolder        Folder?           @relation("ChildToParentFolder", fields: [parentFolderId], references: [id])
}

But when I run DEBUG="*" npx prisma validate I see

  prisma:loadEnv project root found at [...path omited...]\package.json +0ms
  prisma:tryLoadEnv Environment variables loaded from [...path omited...]\.env +0ms
[dotenv][DEBUG] did not match key and value when parsing line 1: # Environment variables declared in this file are automatically made available to Prisma.
[dotenv][DEBUG] did not match key and value when parsing line 2: # See the documentation for more detail: https://pris.ly/d/prisma-schema#using-environment-variables[dotenv][DEBUG] did not match key and value when parsing line 3:
[dotenv][DEBUG] did not match key and value when parsing line 4: # Prisma supports the native connection string format for PostgreSQL, MySQL, SQLite, SQL Server and 
MongoDB (Preview).
[dotenv][DEBUG] did not match key and value when parsing line 5: # See the documentation for all the connection string options: https://pris.ly/d/connection-strings 
[dotenv][DEBUG] did not match key and value when parsing line 6:
[dotenv][DEBUG] did not match key and value when parsing line 12:
Environment variables loaded from .env
  prisma:engines binaries to download libquery-engine, migration-engine, introspection-engine, prisma-fmt +0ms
Prisma schema loaded from prisma\schema.prisma
  prisma:getDMMF Using CLI Query Engine (Node-API) at: [...path omited...]\node_modules\@prisma\engines\query_engine-windows.dll.node +0ms
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', libs\datamodel\connectors\dml\src\model.rs:290:47
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: SyntaxError: Unexpected token c in JSON at position 0
    at JSON.parse (<anonymous>)
    at getDmmfNodeAPI ([...path omited...]\node_modules\prisma\build\index.js:36492:28)
    at async getDMMF ([...path omited...]\node_modules\prisma\build\index.js:36471:17)
    at async Object.parse ([...path omited...]\node_modules\prisma\build\index.js:104072:5)
    at async main ([...path omited...]\node_modules\prisma\build\index.js:105393:18)

I tried RUST_BACKTRACE=1 to get more info but that spit out the same thing except with the suggestion to try RUST_BACKTRACE=full, so I tried that and get this:

$ RUST_BACKTRACE=full npx prisma validate
Environment variables loaded from .env
Prisma schema loaded from prisma\schema.prisma
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', libs\datamodel\connectors\dml\src\model.rs:290:47
stack backtrace:
   0:     0x7ffb3d4f042e - napi_register_module_v1
   1:     0x7ffb3d50f5ba - rust_eh_personality
   2:     0x7ffb3d4e8d78 - napi_register_module_v1
   3:     0x7ffb3d4f3146 - napi_register_module_v1
   4:     0x7ffb3d4f2c34 - napi_register_module_v1
   5:     0x7ffb3d4f37a5 - napi_register_module_v1
   6:     0x7ffb3d4f335f - napi_register_module_v1
   7:     0x7ffb3d4f0d77 - napi_register_module_v1
   8:     0x7ffb3d4f32e9 - napi_register_module_v1
   9:     0x7ffb3d6a00d0 - rust_eh_personality
  10:     0x7ffb3d6a001c - rust_eh_personality
  11:     0x7ffb3d019a5f - napi_register_module_v1
  12:     0x7ffb3ce5a436 - napi_register_module_v1
  13:     0x7ffb3cebef74 - napi_register_module_v1
  14:     0x7ffb3ce5826f - napi_register_module_v1
  15:     0x7ffb3c22644d - <unknown>
  16:     0x7ffb3c23d010 - <unknown>
  17:     0x7ffb3c25514b - <unknown>
  18:     0x7ff74de2aac7 - node::Stop
  19:     0x7ff74e67f11f - v8::internal::Builtins::builtin_handle
  20:     0x7ff74e67e6b4 - v8::internal::Builtins::builtin_handle
  21:     0x7ff74e67e9a8 - v8::internal::Builtins::builtin_handle
  22:     0x7ff74e67e7f3 - v8::internal::Builtins::builtin_handle
  23:     0x7ff74e75d67d - v8::internal::SetupIsolateDelegate::SetupHeap
  24:     0x7ff74e6f3762 - v8::internal::SetupIsolateDelegate::SetupHeap
  25:     0x7ff74e721810 - v8::internal::SetupIsolateDelegate::SetupHeap
  26:     0x7ff74e79fc6e - v8::internal::SetupIsolateDelegate::SetupHeap
  27:     0x7ff74e713a10 - v8::internal::SetupIsolateDelegate::SetupHeap
  28:     0x7ff74e6f130c - v8::internal::SetupIsolateDelegate::SetupHeap
  29:     0x7ff74e5c0b10 - v8::internal::Execution::CallWasm
  30:     0x7ff74e5c0c1b - v8::internal::Execution::CallWasm
  31:     0x7ff74e5c165a - v8::internal::Execution::TryCall
  32:     0x7ff74e5a1735 - v8::internal::MicrotaskQueue::RunMicrotasks
  33:     0x7ff74e5a1490 - v8::internal::MicrotaskQueue::PerformCheckpoint
  34:     0x7ff74de80904 - node::CallbackScope::~CallbackScope
  35:     0x7ff74de80d3b - node::CallbackScope::~CallbackScope
  36:     0x7ff74de789c4 - v8::internal::compiler::Operator::EffectOutputCount
  37:     0x7ff74dde5eb5 - SSL_get_quiet_shutdown
  38:     0x7ff74ddd933e - v8::base::CPU::has_sse
  39:     0x7ff74deb4e47 - uv_timer_stop
  40:     0x7ff74deb141b - uv_async_send
  41:     0x7ff74deb0bac - uv_loop_init
  42:     0x7ff74deb0d4a - uv_run
  43:     0x7ff74dda8a45 - v8::internal::AsmJsScanner::GetIdentifierString
  44:     0x7ff74de21227 - node::Start
  45:     0x7ff74dc7685c - RC4_options
  46:     0x7ff74ec31c08 - v8::internal::compiler::RepresentationChanger::Uint32OverflowOperatorFor
  47:     0x7ffb97cc7034 - BaseThreadInitThunk
  48:     0x7ffb97e02651 - RtlUserThreadStart
Error: Unexpected token c in JSON at position 0

How to reproduce

1. Make self-referencing model in Prisma2 schema as shown above
2. Run npx prisma validate
3. become saddened by error

Expected behavior

Ideally, validation would check the file

Environment & setup

• OS: Windows (above from within Git Bash terminal in VS Code)
• Database: MySQL
• Node.js version: v14.18.0

Prisma Version

prisma                  : 3.4.0
@prisma/client          : 3.4.0
Current platform        : windows
Query Engine (Node-API) : libquery-engine 1c9fdaa9e2319b814822d6dbfd0a69e1fcc13a85 (at node_modules\@prisma\engines\query_engine-windows.dll.node)
Migration Engine        : migration-engine-cli 1c9fdaa9e2319b814822d6dbfd0a69e1fcc13a85 (at node_modules\@prisma\engines\migration-engine-windows.exe)
Introspection Engine    : introspection-core 1c9fdaa9e2319b814822d6dbfd0a69e1fcc13a85 (at node_modules\@prisma\engines\introspection-engine-windows.exe)
Format Binary           : prisma-fmt 1c9fdaa9e2319b814822d6dbfd0a69e1fcc13a85 (at node_modules\@prisma\engines\prisma-fmt-windows.exe)
Default Engines Hash    : 1c9fdaa9e2319b814822d6dbfd0a69e1fcc13a85
Studio                  : 0.438.0

[janpio]

In Prisma 3.3.0 the validate and format comamnd gave a much more helpful error message:

λ npx prisma@3.3.0 format
Environment variables loaded from .env
Prisma schema loaded from prisma\schema.prisma
Error: Schema parsing
error: Error parsing attribute "@relation": The relation field `user` on Model `Referral` is required. This is no longer valid because it's not possible to enforce this constraint on the database level. Please change the field type from `User` to `User?` to fix this.
  -->  schema.prisma:21
   |
20 |   id   String @id @default(cuid()) @db.Char(30)
21 |   user User   @relation("UserToReferral")
22 | }
   |

Validation Error Count: 1

[janpio]

I can confirm that this schema causes a crash:

model User {
  id         String    @id @default(cuid()) @db.Char(30)
  referralId String    @unique @db.Char(30)
  referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id])
}
model Referral {
  id   String @id @default(cuid()) @db.Char(30)
  user User   @relation("UserToReferral")
}

So although something might be weird or wrong with your schema, the crash is of course unexpected and should be a helpful validation error message instead.

λ npx prisma validate
Environment variables loaded from .env
Prisma schema loaded from prisma\schema.prisma
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', libs\datamodel\connectors\dml\src\model.rs:290:47
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: Unexpected token c in JSON at position 0

---

Using prisma format on the schema leads to validation errors:

λ npx prisma format
Environment variables loaded from .env
Prisma schema loaded from prisma\schema.prisma
Error: Schema parsing
error: Error parsing attribute "@relation": The relation fields `user` on Model `Referral` and `referral` on Model `User` both provide the `references` argument in the @relation attribute. You have to provide it only on one of the two fields.
  -->  schema.prisma:21
   |
20 |   id     String @id @default(cuid()) @db.Char(30)
21 |   user   User   @relation("UserToReferral", fields: [userId], references: [id])
22 |   userId String @db.Char(30)
   |
error: Error parsing attribute "@relation": The relation fields `user` on Model `Referral` and `referral` on Model `User` both provide the `references` argument in the @relation attribute. You have to provide it only on one of the two fields.
  -->  schema.prisma:16
   |
15 |   referralId String    @unique @db.Char(30)
16 |   referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id], map: "User_referralId_fkey")
17 | }
   |
error: Error parsing attribute "@relation": The relation fields `user` on Model `Referral` and `referral` on Model `User` both provide the `fields` argument in the @relation attribute. You have to provide it only on one of the two fields.
  -->  schema.prisma:21
   |
20 |   id     String @id @default(cuid()) @db.Char(30)
21 |   user   User   @relation("UserToReferral", fields: [userId], references: [id])
22 |   userId String @db.Char(30)
   |
error: Error parsing attribute "@relation": The relation fields `user` on Model `Referral` and `referral` on Model `User` both provide the `fields` argument in the @relation attribute. You have to provide it only on one of the two fields.
  -->  schema.prisma:16
   |
15 |   referralId String    @unique @db.Char(30)
16 |   referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id], map: "User_referralId_fkey")
17 | }
   |

Validation Error Count: 4

Using Format Document in the VSCode extension has a different effect:

model User {
  id         String    @id @default(cuid()) @db.Char(30)
  referralId String    @unique @db.Char(30)
  referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id], map: "User_referralId_fkey")
}

model Referral {
  id     String @id @default(cuid()) @db.Char(30)
  user   User   @relation("UserToReferral", fields: [userId], references: [id])
  userId String @db.Char(30)
}

Running that again, keeps changing the schema!

model User {
  id         String    @id @default(cuid()) @db.Char(30)
  referralId String    @unique @db.Char(30)
  referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id], map: "User_referralId_fkey")
}

model Referral {
  id     String @id @default(cuid()) @db.Char(30)
  user   User   @relation("UserToReferral", fields: [userId], references: [id])
  userId String @db.Char(30)@unique
}

(adds @unique to the last field without a space)

model User {
  id         String    @id @default(cuid()) @db.Char(30)
  referralId String    @unique @db.Char(30)
  referral   Referral? @relation("UserToReferral", fields: [referralId], references: [id], map: "User_referralId_fkey")
}

model Referral {
  id     String @id @default(cuid()) @db.Char(30)
  user   User   @relation("UserToReferral", fields: [userId], references: [id])
  userId String @unique @db.Char(30)
}

(fixes the order in the last field and adds the space)