show error message when database is not running (#1218)

Co-authored-by: Martin Šošić <Martinsos@users.noreply.github.com>
Co-authored-by: Mihovil Ilakovac <mihovil@ilakovac.com>

waspc/cli/src/Wasp/Cli/Command.hs

@@ -1,24 +1,35 @@
+{-# LANGUAGE GADTs #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 
 module Wasp.Cli.Command
   ( Command,
     runCommand,
     CommandError (..),
+
+    -- * Requirements
+
+    -- See "Wasp.Cli.Command.Requires" for documentation.
+    require,
+    Requirable (checkRequirement),
   )
 where
 
-import Control.Monad.Except (ExceptT, MonadError, runExceptT)
+import Control.Monad.Error.Class (MonadError)
+import Control.Monad.Except (ExceptT, runExceptT)
 import Control.Monad.IO.Class (MonadIO)
+import Control.Monad.State.Strict (StateT, evalStateT, gets, modify)
+import Data.Data (Typeable, cast)
+import Data.Maybe (mapMaybe)
 import System.Exit (exitFailure)
 import Wasp.Cli.Message (cliSendMessage)
 import qualified Wasp.Message as Msg
 
-newtype Command a = Command {_runCommand :: ExceptT CommandError IO a}
+newtype Command a = Command {_runCommand :: StateT [Requirement] (ExceptT CommandError IO) a}
   deriving (Functor, Applicative, Monad, MonadIO, MonadError CommandError)
 
 runCommand :: Command a -> IO ()
 runCommand cmd = do
-  runExceptT (_runCommand cmd) >>= \case
+  runExceptT (flip evalStateT [] $ _runCommand cmd) >>= \case
     Left cmdError -> do
       cliSendMessage $ Msg.Failure (_errorTitle cmdError) (_errorMsg cmdError)
       exitFailure
@@ -27,3 +38,33 @@ runCommand cmd = do
 -- TODO: What if we want to recognize errors in order to handle them?
 --   Should we add _commandErrorType? Should CommandError be parametrized by it, is that even possible?
 data CommandError = CommandError {_errorTitle :: !String, _errorMsg :: !String}
+
+data Requirement where
+  Requirement :: Requirable r => r -> Requirement
+
+class Typeable r => Requirable r where
+  -- | Check if the requirement is met and return a value representing that
+  -- requirement.
+  --
+  -- This function must always return a value: if the requirement is not met,
+  -- throw a 'CommandError'.
+  checkRequirement :: Command r
+
+-- | Assert that a requirement is met and receive information about that
+-- requirement, if any is offered.
+--
+-- To use, pattern match on the result, e.g.
+--
+-- @
+-- do
+--   HasDbConnection <- require
+-- @
+require :: Requirable r => Command r
+require =
+  Command (gets (mapMaybe cast)) >>= \case
+    (req : _) -> return req
+    [] -> do
+      -- Requirement hasn't been met, so run the check
+      req <- checkRequirement
+      Command $ modify (Requirement req :)
+      return req

waspc/cli/src/Wasp/Cli/Command/Build.hs

@@ -13,11 +13,9 @@ import System.Directory
     removeDirectoryRecursive,
   )
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common
-  ( findWaspProjectRootDirFromCwd,
-  )
 import Wasp.Cli.Command.Compile (compileIOWithOptions, printCompilationResult)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import Wasp.Cli.Message (cliSendMessage)
 import Wasp.CompileOptions (CompileOptions (..))
@@ -35,7 +33,7 @@ import Wasp.Project (CompileError, CompileWarning)
 -- Very similar to 'compile'.
 build :: Command ()
 build = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let buildDir =
         waspProjectDir </> Common.dotWaspDirInWaspProjectDir
           </> Common.buildDirInDotWaspDir

waspc/cli/src/Wasp/Cli/Command/Clean.hs

@@ -10,14 +10,14 @@ import System.Directory
     removeDirectoryRecursive,
   )
 import Wasp.Cli.Command (Command)
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import qualified Wasp.Message as Msg
 
 clean :: Command ()
 clean = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let dotWaspDirFp = SP.toFilePath $ waspProjectDir SP.</> Common.dotWaspDirInWaspProjectDir
   cliSendMessageC $ Msg.Start "Deleting .wasp/ directory..."
   doesDotWaspDirExist <- liftIO $ doesDirectoryExist dotWaspDirFp

waspc/cli/src/Wasp/Cli/Command/Common.hs

@@ -1,52 +1,20 @@
 module Wasp.Cli.Command.Common
-  ( findWaspProjectRootDirFromCwd,
+  ( readWaspCompileInfo,
-    findWaspProjectRoot,
-    readWaspCompileInfo,
     throwIfExeIsNotAvailable,
   )
 where
 
 import Control.Monad.Except
 import qualified Control.Monad.Except as E
-import Data.Maybe (fromJust)
 import StrongPath (Abs, Dir, Path')
-import qualified StrongPath as SP
 import StrongPath.Operations
-import System.Directory (doesFileExist, doesPathExist, findExecutable, getCurrentDirectory)
+import System.Directory (findExecutable)
-import qualified System.FilePath as FP
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Common (dotWaspRootFileInWaspProjectDir)
 import qualified Wasp.Cli.Common as Cli.Common
 import Wasp.Project (WaspProjectDir)
 import Wasp.Util (ifM)
 import qualified Wasp.Util.IO as IOUtil
 
-findWaspProjectRoot :: Path' Abs (Dir ()) -> Command (Path' Abs (Dir WaspProjectDir))
-findWaspProjectRoot currentDir = do
-  let absCurrentDirFp = SP.fromAbsDir currentDir
-  doesCurrentDirExist <- liftIO $ doesPathExist absCurrentDirFp
-  unless doesCurrentDirExist (throwError notFoundError)
-  let dotWaspRootFilePath = absCurrentDirFp FP.</> SP.fromRelFile dotWaspRootFileInWaspProjectDir
-  isCurrentDirRoot <- liftIO $ doesFileExist dotWaspRootFilePath
-  if isCurrentDirRoot
-    then return $ SP.castDir currentDir
-    else do
-      let parentDir = SP.parent currentDir
-      when (parentDir == currentDir) (throwError notFoundError)
-      findWaspProjectRoot parentDir
-  where
-    notFoundError =
-      CommandError
-        "Wasp command failed"
-        ( "Couldn't find wasp project root - make sure"
-            ++ " you are running this command from a Wasp project."
-        )
-
-findWaspProjectRootDirFromCwd :: Command (Path' Abs (Dir WaspProjectDir))
-findWaspProjectRootDirFromCwd = do
-  absCurrentDir <- liftIO getCurrentDirectory
-  findWaspProjectRoot (fromJust $ SP.parseAbsDir absCurrentDir)
-
 readWaspCompileInfo :: Path' Abs (Dir WaspProjectDir) -> IO String
 readWaspCompileInfo waspDir =
   ifM

waspc/cli/src/Wasp/Cli/Command/Compile.hs

@@ -18,10 +18,8 @@ import Data.List (intercalate)
 import StrongPath (Abs, Dir, Path', (</>))
 import qualified Wasp.AppSpec as AS
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common
-  ( findWaspProjectRootDirFromCwd,
-  )
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import Wasp.Cli.Message (cliSendMessage)
 import Wasp.CompileOptions (CompileOptions (..))
@@ -36,7 +34,7 @@ compile = do
   -- TODO: Consider a way to remove the redundancy of finding the project root
   -- here and in compileWithOptions. One option could be to add this to defaultCompileOptions
   -- add make externalCodeDirPath a helper function, along with any others we typically need.
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   compileWithOptions $ defaultCompileOptions waspProjectDir
 
 -- | Compiles Wasp project that the current working directory is part of.
@@ -47,7 +45,7 @@ compile = do
 -- Finally, throws if there was a compile error, otherwise returns any compile warnings.
 compileWithOptions :: CompileOptions -> Command [CompileWarning]
 compileWithOptions options = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let outDir =
         waspProjectDir </> Common.dotWaspDirInWaspProjectDir
           </> Common.generatedCodeDirInDotWaspDir

waspc/cli/src/Wasp/Cli/Command/Db.hs

@@ -4,8 +4,8 @@ module Wasp.Cli.Command.Db
 where
 
 import Wasp.Cli.Command (Command, runCommand)
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (compileWithOptions, defaultCompileOptions)
+import Wasp.Cli.Command.Require (DbConnectionEstablished (DbConnectionEstablished), InWaspProject (InWaspProject), require)
 import Wasp.CompileOptions (CompileOptions (generatorWarningsFilter))
 import Wasp.Generator.Monad (GeneratorWarning (GeneratorNeedsMigrationWarning))
 
@@ -19,8 +19,9 @@ runDbCommand = runCommand . makeDbCommand
 makeDbCommand :: Command a -> Command a
 makeDbCommand cmd = do
   -- Ensure code is generated and npm dependencies are installed.
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   _ <- compileWithOptions $ compileOptions waspProjectDir
+  DbConnectionEstablished <- require
   cmd
   where
     compileOptions waspProjectDir =

waspc/cli/src/Wasp/Cli/Command/Db/Migrate.hs

@@ -8,10 +8,8 @@ import Control.Monad.Except (ExceptT (ExceptT), liftEither, runExceptT, throwErr
 import Control.Monad.IO.Class (liftIO)
 import StrongPath (Abs, Dir, Path', (</>))
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common
-  ( findWaspProjectRootDirFromCwd,
-  )
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Cli.Common
 import Wasp.Generator.Common (ProjectRootDir)
 import Wasp.Generator.DbGenerator.Common (MigrateArgs (..), defaultMigrateArgs)
@@ -24,7 +22,7 @@ import Wasp.Project.Db.Migrations (DbMigrationsDir, dbMigrationsDirInWaspProject
 -- The migrate function takes care of copying migrations from the generated project back to the source code.
 migrateDev :: [String] -> Command ()
 migrateDev optionalMigrateArgs = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let waspDbMigrationsDir = waspProjectDir </> dbMigrationsDirInWaspProjectDir
   let projectRootDir =
         waspProjectDir

waspc/cli/src/Wasp/Cli/Command/Db/Reset.hs

@@ -6,15 +6,15 @@ where
 import Control.Monad.IO.Class (liftIO)
 import StrongPath ((</>))
 import Wasp.Cli.Command (Command)
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import Wasp.Generator.DbGenerator.Operations (dbReset)
 import qualified Wasp.Message as Msg
 
 reset :: Command ()
 reset = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let genProjectDir =
         waspProjectDir </> Common.dotWaspDirInWaspProjectDir </> Common.generatedCodeDirInDotWaspDir
 

waspc/cli/src/Wasp/Cli/Command/Db/Seed.hs

@@ -16,16 +16,16 @@ import qualified Wasp.AppSpec.App.Db as AS.Db
 import qualified Wasp.AppSpec.ExtImport as AS.ExtImport
 import qualified Wasp.AppSpec.Valid as ASV
 import Wasp.Cli.Command (Command, CommandError (CommandError))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (analyze)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import Wasp.Generator.DbGenerator.Operations (dbSeed)
 import qualified Wasp.Message as Msg
 
 seed :: Maybe String -> Command ()
 seed maybeUserProvidedSeedName = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let genProjectDir =
         waspProjectDir </> Common.dotWaspDirInWaspProjectDir </> Common.generatedCodeDirInDotWaspDir
 

waspc/cli/src/Wasp/Cli/Command/Db/Studio.hs

@@ -8,8 +8,8 @@ import Control.Concurrent.Async (concurrently)
 import Control.Monad.IO.Class (liftIO)
 import StrongPath ((</>))
 import Wasp.Cli.Command (Command)
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Cli.Common as Common
 import Wasp.Generator.DbGenerator.Jobs (runStudio)
 import Wasp.Generator.Job.IO (readJobMessagesAndPrintThemPrefixed)
@@ -17,7 +17,7 @@ import qualified Wasp.Message as Msg
 
 studio :: Command ()
 studio = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   let genProjectDir =
         waspProjectDir </> Common.dotWaspDirInWaspProjectDir </> Common.generatedCodeDirInDotWaspDir
 

waspc/cli/src/Wasp/Cli/Command/Deploy.hs

@@ -7,12 +7,12 @@ import Control.Monad.Except (throwError)
 import Control.Monad.IO.Class (liftIO)
 import System.Environment (getExecutablePath)
 import Wasp.Cli.Command (Command, CommandError (CommandError))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import qualified Wasp.Project.Deployment
 
 deploy :: [String] -> Command ()
 deploy cmdArgs = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   deployResult <- liftIO $ do
     -- `getExecutablePath` has some caveats:
     --   https://frasertweedale.github.io/blog-fp/posts/2022-05-10-improved-executable-path-queries.html

waspc/cli/src/Wasp/Cli/Command/Deps.hs

@@ -8,8 +8,8 @@ import Control.Monad.IO.Class (liftIO)
 import Wasp.AppSpec (AppSpec)
 import qualified Wasp.AppSpec.App.Dependency as AS.Dependency
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (defaultCompileOptions)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Cli.Terminal (title)
 import qualified Wasp.Generator.NpmDependencies as N
 import qualified Wasp.Generator.ServerGenerator as ServerGenerator
@@ -19,7 +19,7 @@ import qualified Wasp.Util.Terminal as Term
 
 deps :: Command ()
 deps = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   appSpecOrAnalyzerErrors <- liftIO $ analyzeWaspProject waspProjectDir (defaultCompileOptions waspProjectDir)
   appSpec <-
     either

waspc/cli/src/Wasp/Cli/Command/Dockerfile.hs

@@ -7,13 +7,13 @@ import Control.Monad.Except (throwError)
 import Control.Monad.IO.Class (liftIO)
 import qualified Data.Text.IO as T.IO
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (defaultCompileOptions)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Project (compileAndRenderDockerfile)
 
 printDockerfile :: Command ()
 printDockerfile = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   dockerfileContentOrCompileErrors <- liftIO $ compileAndRenderDockerfile waspProjectDir (defaultCompileOptions waspProjectDir)
   either
     (throwError . CommandError "Displaying Dockerfile failed due to a compilation error in your Wasp project" . unwords)

waspc/cli/src/Wasp/Cli/Command/Info.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE TypeApplications #-}
-
 module Wasp.Cli.Command.Info
   ( info,
   )
@@ -12,9 +10,10 @@ import StrongPath.Operations ()
 import System.Directory (getFileSize)
 import qualified Wasp.AppSpec.Valid as ASV
 import Wasp.Cli.Command (Command)
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd, readWaspCompileInfo)
+import Wasp.Cli.Command.Common (readWaspCompileInfo)
 import Wasp.Cli.Command.Compile (analyze)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Cli.Command.Start.Db (getDbSystem)
 import Wasp.Cli.Terminal (title)
 import qualified Wasp.Message as Msg
@@ -24,7 +23,7 @@ import qualified Wasp.Util.Terminal as Term
 
 info :: Command ()
 info = do
-  waspDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspDir <- require
 
   compileInfo <- liftIO $ readWaspCompileInfo waspDir
   projectSize <- liftIO $ readDirectorySizeMB waspDir

waspc/cli/src/Wasp/Cli/Command/Require.hs

@@ -0,0 +1,98 @@
+module Wasp.Cli.Command.Require
+  ( -- * Asserting Requirements
+
+    -- There are some requirements we want to assert in command code, such as
+    -- ensuring the command is being run inside a wasp project directory. We
+    -- might end up wanting to check each requirement multiple times, especially
+    -- if we want the value from it (like getting the wasp project directory),
+    -- but we also want to avoid duplicating work. Using 'require' results in
+    -- checked requirements being stored so they can be immediately retrieved
+    -- when checking the same requirements additional times.
+    --
+    -- For example, you can check if you are in a wasp project by doing
+    --
+    -- @
+    -- do
+    --   InWaspProject waspProjectDir <- require
+    -- @
+    --
+    -- See instances of 'Requirable' for what kinds of requirements are
+    -- supported. To implement a new requirable type, give your type an instance
+    -- of 'Requirable'.
+    require,
+
+    -- * Requirables
+    Requirable (checkRequirement),
+    DbConnectionEstablished (DbConnectionEstablished),
+    InWaspProject (InWaspProject),
+  )
+where
+
+import Control.Monad (unless, when)
+import Control.Monad.Error.Class (throwError)
+import Control.Monad.IO.Class (liftIO)
+import Data.Data (Typeable)
+import Data.Maybe (fromJust)
+import qualified StrongPath as SP
+import System.Directory (doesFileExist, doesPathExist, getCurrentDirectory)
+import qualified System.FilePath as FP
+import Wasp.Cli.Command (CommandError (CommandError), Requirable (checkRequirement), require)
+import Wasp.Cli.Common (WaspProjectDir)
+import qualified Wasp.Cli.Common as Cli.Common
+import Wasp.Generator.DbGenerator.Operations (isDbRunning)
+
+data DbConnectionEstablished = DbConnectionEstablished deriving (Typeable)
+
+instance Requirable DbConnectionEstablished where
+  checkRequirement = do
+    -- NOTE: 'InWaspProject' does not depend on this requirement, so this
+    -- call to 'require' will not result in an infinite loop.
+    InWaspProject waspProjectDir <- require
+    let outDir = waspProjectDir SP.</> Cli.Common.dotWaspDirInWaspProjectDir SP.</> Cli.Common.generatedCodeDirInDotWaspDir
+    dbIsRunning <- liftIO $ isDbRunning outDir
+    if dbIsRunning
+      then return DbConnectionEstablished
+      else throwError noDbError
+    where
+      noDbError =
+        CommandError
+          "Can not connect to database"
+          ( "The database needs to be running in order to execute this command."
+              ++ " You can easily start a managed dev database with `wasp start db`."
+          )
+
+-- | Require a Wasp project to exist near the current directory. Get the
+-- project directory by pattern matching on the result of 'require':
+--
+-- @
+-- do
+--   InWaspProject waspProjectDir <- require
+-- @
+newtype InWaspProject = InWaspProject (SP.Path' SP.Abs (SP.Dir WaspProjectDir)) deriving (Typeable)
+
+instance Requirable InWaspProject where
+  checkRequirement = do
+    -- Recursively searches up from CWD until @.wasproot@ file is found, or
+    -- throw an error if it is never found.
+    currentDir <- fromJust . SP.parseAbsDir <$> liftIO getCurrentDirectory
+    findWaspProjectRoot currentDir
+    where
+      findWaspProjectRoot currentDir = do
+        let absCurrentDirFp = SP.fromAbsDir currentDir
+        doesCurrentDirExist <- liftIO $ doesPathExist absCurrentDirFp
+        unless doesCurrentDirExist (throwError notFoundError)
+        let dotWaspRootFilePath = absCurrentDirFp FP.</> SP.fromRelFile Cli.Common.dotWaspRootFileInWaspProjectDir
+        isCurrentDirRoot <- liftIO $ doesFileExist dotWaspRootFilePath
+        if isCurrentDirRoot
+          then return $ InWaspProject $ SP.castDir currentDir
+          else do
+            let parentDir = SP.parent currentDir
+            when (parentDir == currentDir) (throwError notFoundError)
+            findWaspProjectRoot parentDir
+
+      notFoundError =
+        CommandError
+          "Wasp command failed"
+          ( "Couldn't find wasp project root - make sure"
+              ++ " you are running this command from a Wasp project."
+          )

waspc/cli/src/Wasp/Cli/Command/Start.hs

@@ -10,9 +10,9 @@ import Control.Monad.Except (throwError)
 import Control.Monad.IO.Class (liftIO)
 import StrongPath ((</>))
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (compile, printWarningsAndErrorsIfAny)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (DbConnectionEstablished (DbConnectionEstablished), InWaspProject (InWaspProject), require)
 import Wasp.Cli.Command.Watch (watch)
 import qualified Wasp.Cli.Common as Common
 import qualified Wasp.Generator
@@ -23,13 +23,15 @@ import Wasp.Project (CompileError, CompileWarning)
 -- It also listens for any file changes and recompiles and restarts generated project accordingly.
 start :: Command ()
 start = do
-  waspRoot <- findWaspProjectRootDirFromCwd
+  InWaspProject waspRoot <- require
   let outDir = waspRoot </> Common.dotWaspDirInWaspProjectDir </> Common.generatedCodeDirInDotWaspDir
 
   cliSendMessageC $ Msg.Start "Starting compilation and setup phase. Hold tight..."
 
   warnings <- compile
 
+  DbConnectionEstablished <- require
+
   cliSendMessageC $ Msg.Start "Listening for file changes..."
   cliSendMessageC $ Msg.Start "Starting up generated project..."
 

waspc/cli/src/Wasp/Cli/Command/Start/Db.hs

@@ -18,9 +18,10 @@ import qualified Wasp.AppSpec.App as AS.App
 import qualified Wasp.AppSpec.App.Db as AS.App.Db
 import qualified Wasp.AppSpec.Valid as ASV
 import Wasp.Cli.Command (Command, CommandError (CommandError))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd, throwIfExeIsNotAvailable)
+import Wasp.Cli.Command.Common (throwIfExeIsNotAvailable)
 import Wasp.Cli.Command.Compile (analyze)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Cli.Common (WaspProjectDir)
 import qualified Wasp.Message as Msg
 import Wasp.Project.Db (databaseUrlEnvVarName)
@@ -36,7 +37,7 @@ import qualified Wasp.Util.Network.Socket as Socket
 -- in Wasp configuration and spins up a database of appropriate type.
 start :: Command ()
 start = do
-  waspProjectDir <- findWaspProjectRootDirFromCwd
+  InWaspProject waspProjectDir <- require
   appSpec <- analyze waspProjectDir
 
   throwIfCustomDbAlreadyInUse appSpec

waspc/cli/src/Wasp/Cli/Command/Telemetry/Project.hs

@@ -31,7 +31,7 @@ import qualified System.Environment as ENV
 import qualified System.Info
 import Wasp.Cli.Command (Command)
 import qualified Wasp.Cli.Command.Call as Command.Call
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Cli.Command.Telemetry.Common (TelemetryCacheDir)
 import Wasp.Cli.Command.Telemetry.User (UserSignature (..))
 import Wasp.Util (ifM)
@@ -100,7 +100,9 @@ checkIfEnvValueIsTruthy (Just v)
 newtype ProjectHash = ProjectHash {_projectHashValue :: String} deriving (Show)
 
 getWaspProjectPathHash :: Command ProjectHash
-getWaspProjectPathHash = ProjectHash . take 16 . sha256 . SP.toFilePath <$> findWaspProjectRootDirFromCwd
+getWaspProjectPathHash = do
+  InWaspProject waspRoot <- require
+  return . ProjectHash . take 16 . sha256 . SP.toFilePath $ waspRoot
   where
     sha256 :: String -> String
     sha256 = show . hashWith SHA256 . ByteStringUTF8.fromString

waspc/cli/src/Wasp/Cli/Command/Test.hs

@@ -10,9 +10,9 @@ import Control.Monad.IO.Class (liftIO)
 import StrongPath (Abs, Dir, (</>))
 import StrongPath.Types (Path')
 import Wasp.Cli.Command (Command, CommandError (..))
-import Wasp.Cli.Command.Common (findWaspProjectRootDirFromCwd)
 import Wasp.Cli.Command.Compile (compile)
 import Wasp.Cli.Command.Message (cliSendMessageC)
+import Wasp.Cli.Command.Require (InWaspProject (InWaspProject), require)
 import Wasp.Cli.Command.Watch (watch)
 import qualified Wasp.Cli.Common as Common
 import qualified Wasp.Generator
@@ -27,7 +27,7 @@ test _ = throwError $ CommandError "Invalid arguments" "Expected: wasp test clie
 
 watchAndTest :: (Path' Abs (Dir ProjectRootDir) -> IO (Either String ())) -> Command ()
 watchAndTest testRunner = do
-  waspRoot <- findWaspProjectRootDirFromCwd
+  InWaspProject waspRoot <- require
   let outDir = waspRoot </> Common.dotWaspDirInWaspProjectDir </> Common.generatedCodeDirInDotWaspDir
 
   cliSendMessageC $ Msg.Start "Starting compilation and setup phase. Hold tight..."

waspc/headless-test/package-lock.json

@@ -9,27 +9,15 @@
       "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
-        "@prisma/client": "^4.12.0"
+        "@prisma/client": "^4.12.0",
+        "linebyline": "^1.3.0"
       },
       "devDependencies": {
         "@playwright/test": "^1.33.0",
-        "concurrently": "^8.0.1",
         "prisma": "^4.12.0",
         "wait-port": "^1.0.4"
       }
     },
-    "node_modules/@babel/runtime": {
-      "version": "7.21.5",
-      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.21.5.tgz",
-      "integrity": "sha512-8jI69toZqqcsnqGGqwGS4Qb1VwLOEp4hz+CXPywcvjs60u3B4Pom/U/7rm4W8tMOYEB+E9wgD0mW1l3r8qlI9Q==",
-      "dev": true,
-      "dependencies": {
-        "regenerator-runtime": "^0.13.11"
-      },
-      "engines": {
-        "node": ">=6.9.0"
-      }
-    },
     "node_modules/@playwright/test": {
       "version": "1.33.0",
       "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.33.0.tgz",
@@ -87,15 +75,6 @@
       "integrity": "sha512-OPs5WnnT1xkCBiuQrZA4+YAV4HEJejmHneyraIaxsbev5yCEr6KMwINNFP9wQeFIw8FWcoTqF3vQsa5CDaI+8Q==",
       "dev": true
     },
-    "node_modules/ansi-regex": {
-      "version": "5.0.1",
-      "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-5.0.1.tgz",
-      "integrity": "sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ==",
-      "dev": true,
-      "engines": {
-        "node": ">=8"
-      }
-    },
     "node_modules/ansi-styles": {
       "version": "4.3.0",
       "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-4.3.0.tgz",
@@ -139,20 +118,6 @@
         "node": ">=8"
       }
     },
-    "node_modules/cliui": {
-      "version": "8.0.1",
-      "resolved": "https://registry.npmjs.org/cliui/-/cliui-8.0.1.tgz",
-      "integrity": "sha512-BSeNnyus75C4//NQ9gQt1/csTXyo/8Sb+afLAkzAptFuMsod9HFokGNudZpi/oQV73hnVK+sR+5PVRMd+Dr7YQ==",
-      "dev": true,
-      "dependencies": {
-        "string-width": "^4.2.0",
-        "strip-ansi": "^6.0.1",
-        "wrap-ansi": "^7.0.0"
-      },
-      "engines": {
-        "node": ">=12"
-      }
-    },
     "node_modules/color-convert": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",
@@ -180,49 +145,6 @@
         "node": "^12.20.0 || >=14"
       }
     },
-    "node_modules/concurrently": {
-      "version": "8.0.1",
-      "resolved": "https://registry.npmjs.org/concurrently/-/concurrently-8.0.1.tgz",
-      "integrity": "sha512-Sh8bGQMEL0TAmAm2meAXMjcASHZa7V0xXQVDBLknCPa9TPtkY9yYs+0cnGGgfdkW0SV1Mlg+hVGfXcoI8d3MJA==",
-      "dev": true,
-      "dependencies": {
-        "chalk": "^4.1.2",
-        "date-fns": "^2.29.3",
-        "lodash": "^4.17.21",
-        "rxjs": "^7.8.0",
-        "shell-quote": "^1.8.0",
-        "spawn-command": "0.0.2-1",
-        "supports-color": "^8.1.1",
-        "tree-kill": "^1.2.2",
-        "yargs": "^17.7.1"
-      },
-      "bin": {
-        "conc": "dist/bin/concurrently.js",
-        "concurrently": "dist/bin/concurrently.js"
-      },
-      "engines": {
-        "node": "^14.13.0 || >=16.0.0"
-      },
-      "funding": {
-        "url": "https://github.com/open-cli-tools/concurrently?sponsor=1"
-      }
-    },
-    "node_modules/date-fns": {
-      "version": "2.30.0",
-      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-2.30.0.tgz",
-      "integrity": "sha512-fnULvOpxnC5/Vg3NCiWelDsLiUc9bRwAPs/+LfTLNvetFCtCTN+yQz15C/fs4AwX1R9K5GLtLfn8QW+dWisaAw==",
-      "dev": true,
-      "dependencies": {
-        "@babel/runtime": "^7.21.0"
-      },
-      "engines": {
-        "node": ">=0.11"
-      },
-      "funding": {
-        "type": "opencollective",
-        "url": "https://opencollective.com/date-fns"
-      }
-    },
     "node_modules/debug": {
       "version": "4.3.4",
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
@@ -240,21 +162,6 @@
         }
       }
     },
-    "node_modules/emoji-regex": {
-      "version": "8.0.0",
-      "resolved": "https://registry.npmjs.org/emoji-regex/-/emoji-regex-8.0.0.tgz",
-      "integrity": "sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==",
-      "dev": true
-    },
-    "node_modules/escalade": {
-      "version": "3.1.1",
-      "resolved": "https://registry.npmjs.org/escalade/-/escalade-3.1.1.tgz",
-      "integrity": "sha512-k0er2gUkLf8O0zKJiAhmkTnJlTvINGv7ygDNPbeIsX/TJjGJZHuh9B2UxbsaEkmlEo9MfhrSzmhIlhRlI2GXnw==",
-      "dev": true,
-      "engines": {
-        "node": ">=6"
-      }
-    },
     "node_modules/fsevents": {
       "version": "2.3.2",
       "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
@@ -269,15 +176,6 @@
         "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
       }
     },
-    "node_modules/get-caller-file": {
-      "version": "2.0.5",
-      "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
-      "integrity": "sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==",
-      "dev": true,
-      "engines": {
-        "node": "6.* || 8.* || >= 10.*"
-      }
-    },
     "node_modules/has-flag": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
@@ -287,20 +185,10 @@
         "node": ">=8"
       }
     },
-    "node_modules/is-fullwidth-code-point": {
+    "node_modules/linebyline": {
-      "version": "3.0.0",
+      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/linebyline/-/linebyline-1.3.0.tgz",
-      "integrity": "sha512-zymm5+u+sCsSWyD9qNaejV3DFvhCKclKdizYaJUuHA83RLjb7nSuGnddCHGv0hk+KY7BMAlsWeK4Ueg6EV6XQg==",
+      "integrity": "sha512-3fpIYMrSU77OCf89hjXKuCx6vGwgWEu4N5DDCGqgZ1BF0HYy9V8IbQb/3+VWIU17iBQ83qQoUokH0AhPMOTi7w=="
-      "dev": true,
-      "engines": {
-        "node": ">=8"
-      }
-    },
-    "node_modules/lodash": {
-      "version": "4.17.21",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
-      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
-      "dev": true
     },
     "node_modules/ms": {
       "version": "2.1.2",
@@ -337,101 +225,6 @@
         "node": ">=14.17"
       }
     },
-    "node_modules/regenerator-runtime": {
-      "version": "0.13.11",
-      "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.11.tgz",
-      "integrity": "sha512-kY1AZVr2Ra+t+piVaJ4gxaFaReZVH40AKNo7UCX6W+dEwBo/2oZJzqfuN1qLq1oL45o56cPaTXELwrTh8Fpggg==",
-      "dev": true
-    },
-    "node_modules/require-directory": {
-      "version": "2.1.1",
-      "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
-      "integrity": "sha512-fGxEI7+wsG9xrvdjsrlmL22OMTTiHRwAMroiEeMgq8gzoLC/PQr7RsRDSTLUg/bZAZtF+TVIkHc6/4RIKrui+Q==",
-      "dev": true,
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
-    "node_modules/rxjs": {
-      "version": "7.8.1",
-      "resolved": "https://registry.npmjs.org/rxjs/-/rxjs-7.8.1.tgz",
-      "integrity": "sha512-AA3TVj+0A2iuIoQkWEK/tqFjBq2j+6PO6Y0zJcvzLAFhEFIO3HL0vls9hWLncZbAAbK0mar7oZ4V079I/qPMxg==",
-      "dev": true,
-      "dependencies": {
-        "tslib": "^2.1.0"
-      }
-    },
-    "node_modules/shell-quote": {
-      "version": "1.8.1",
-      "resolved": "https://registry.npmjs.org/shell-quote/-/shell-quote-1.8.1.tgz",
-      "integrity": "sha512-6j1W9l1iAs/4xYBI1SYOVZyFcCis9b4KCLQ8fgAGG07QvzaRLVVRQvAy85yNmmZSjYjg4MWh4gNvlPujU/5LpA==",
-      "dev": true,
-      "funding": {
-        "url": "https://github.com/sponsors/ljharb"
-      }
-    },
-    "node_modules/spawn-command": {
-      "version": "0.0.2-1",
-      "resolved": "https://registry.npmjs.org/spawn-command/-/spawn-command-0.0.2-1.tgz",
-      "integrity": "sha512-n98l9E2RMSJ9ON1AKisHzz7V42VDiBQGY6PB1BwRglz99wpVsSuGzQ+jOi6lFXBGVTCrRpltvjm+/XA+tpeJrg==",
-      "dev": true
-    },
-    "node_modules/string-width": {
-      "version": "4.2.3",
-      "resolved": "https://registry.npmjs.org/string-width/-/string-width-4.2.3.tgz",
-      "integrity": "sha512-wKyQRQpjJ0sIp62ErSZdGsjMJWsap5oRNihHhu6G7JVO/9jIB6UyevL+tXuOqrng8j/cxKTWyWUwvSTriiZz/g==",
-      "dev": true,
-      "dependencies": {
-        "emoji-regex": "^8.0.0",
-        "is-fullwidth-code-point": "^3.0.0",
-        "strip-ansi": "^6.0.1"
-      },
-      "engines": {
-        "node": ">=8"
-      }
-    },
-    "node_modules/strip-ansi": {
-      "version": "6.0.1",
-      "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.1.tgz",
-      "integrity": "sha512-Y38VPSHcqkFrCpFnQ9vuSXmquuv5oXOKpGeT6aGrr3o3Gc9AlVa6JBfUSOCnbxGGZF+/0ooI7KrPuUSztUdU5A==",
-      "dev": true,
-      "dependencies": {
-        "ansi-regex": "^5.0.1"
-      },
-      "engines": {
-        "node": ">=8"
-      }
-    },
-    "node_modules/supports-color": {
-      "version": "8.1.1",
-      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-8.1.1.tgz",
-      "integrity": "sha512-MpUEN2OodtUzxvKQl72cUF7RQ5EiHsGvSsVG0ia9c5RbWGL2CI4C7EpPS8UTBIplnlzZiNuV56w+FuNxy3ty2Q==",
-      "dev": true,
-      "dependencies": {
-        "has-flag": "^4.0.0"
-      },
-      "engines": {
-        "node": ">=10"
-      },
-      "funding": {
-        "url": "https://github.com/chalk/supports-color?sponsor=1"
-      }
-    },
-    "node_modules/tree-kill": {
-      "version": "1.2.2",
-      "resolved": "https://registry.npmjs.org/tree-kill/-/tree-kill-1.2.2.tgz",
-      "integrity": "sha512-L0Orpi8qGpRG//Nd+H90vFB+3iHnue1zSSGmNOOCh1GLJ7rUKVwV2HvijphGQS2UmhUZewS9VgvxYIdgr+fG1A==",
-      "dev": true,
-      "bin": {
-        "tree-kill": "cli.js"
-      }
-    },
-    "node_modules/tslib": {
-      "version": "2.5.0",
-      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.5.0.tgz",
-      "integrity": "sha512-336iVw3rtn2BUK7ORdIAHTyxHGRIHVReokCR3XjbckJMK7ms8FysBfhLR8IXnAgy7T0PTPNBWKiH514FOW/WSg==",
-      "dev": true
-    },
     "node_modules/wait-port": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/wait-port/-/wait-port-1.0.4.tgz",
@@ -448,59 +241,6 @@
       "engines": {
         "node": ">=10"
       }
-    },
-    "node_modules/wrap-ansi": {
-      "version": "7.0.0",
-      "resolved": "https://registry.npmjs.org/wrap-ansi/-/wrap-ansi-7.0.0.tgz",
-      "integrity": "sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q==",
-      "dev": true,
-      "dependencies": {
-        "ansi-styles": "^4.0.0",
-        "string-width": "^4.1.0",
-        "strip-ansi": "^6.0.0"
-      },
-      "engines": {
-        "node": ">=10"
-      },
-      "funding": {
-        "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
-      }
-    },
-    "node_modules/y18n": {
-      "version": "5.0.8",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.8.tgz",
-      "integrity": "sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA==",
-      "dev": true,
-      "engines": {
-        "node": ">=10"
-      }
-    },
-    "node_modules/yargs": {
-      "version": "17.7.2",
-      "resolved": "https://registry.npmjs.org/yargs/-/yargs-17.7.2.tgz",
-      "integrity": "sha512-7dSzzRQ++CKnNI/krKnYRV7JKKPUXMEh61soaHKg9mrWEhzFWhFnxPxGl+69cD1Ou63C13NUPCnmIcrvqCuM6w==",
-      "dev": true,
-      "dependencies": {
-        "cliui": "^8.0.1",
-        "escalade": "^3.1.1",
-        "get-caller-file": "^2.0.5",
-        "require-directory": "^2.1.1",
-        "string-width": "^4.2.3",
-        "y18n": "^5.0.5",
-        "yargs-parser": "^21.1.1"
-      },
-      "engines": {
-        "node": ">=12"
-      }
-    },
-    "node_modules/yargs-parser": {
-      "version": "21.1.1",
-      "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-21.1.1.tgz",
-      "integrity": "sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==",
-      "dev": true,
-      "engines": {
-        "node": ">=12"
-      }
     }
   }
 }

waspc/headless-test/package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "example-app:start": "concurrently \"npm:example-app:start-db\" \"npm:example-app:start-app\" --kill-others-on-fail",
+    "example-app:start": "node start.js",
     "example-app:start-db": "npm run example-app:cleanup-db && cd ./examples/todoApp && cabal run wasp-cli start db",
     "example-app:start-app": "npm run example-app:wait-for-db && cd ./examples/todoApp && cabal run wasp-cli db migrate-dev && cabal run wasp-cli start",
     "example-app:wait-for-db": "sleep 5 && ./node_modules/.bin/wait-port 5432",
@@ -15,9 +15,9 @@
   "license": "ISC",
   "devDependencies": {
     "@playwright/test": "^1.33.0",
-    "concurrently": "^8.0.1",
     "prisma": "^4.12.0",
-    "wait-port": "^1.0.4"
+    "wait-port": "^1.0.4",
+    "linebyline": "^1.3.0"
   },
   "dependencies": {
     "@prisma/client": "^4.12.0"

waspc/headless-test/start.js

@@ -0,0 +1,31 @@
+const cp = require('child_process');
+const readline = require('linebyline');
+
+function spawn(name, cmd, args, done) {
+  const spawnOptions = {
+    detached: true,
+  };
+  const proc = cp.spawn(cmd, args, spawnOptions);
+
+  // We close stdin stream on the new process because otherwise the start-app
+  // process hangs.
+  // See https://github.com/wasp-lang/wasp/pull/1218#issuecomment-1599098272.
+  proc.stdin.destroy();
+
+  readline(proc.stdout).on('line', data => {
+    console.log(`\x1b[0m\x1b[33m[${name}][out]\x1b[0m ${data}`);
+  });
+  readline(proc.stderr).on('line', data => {
+    console.log(`\x1b[0m\x1b[33m[${name}][err]\x1b[0m ${data}`);
+  });
+  proc.on('exit', done);
+}
+
+// Exit if either child fails
+const cb = (code) => {
+  if (code !== 0) {
+    process.exit(code);
+  }
+}
+spawn('app', 'npm', ['run', 'example-app:start-app'], cb);
+spawn('db', 'npm', ['run', 'example-app:start-db'], cb)

waspc/src/Wasp/Generator/DbGenerator/Jobs.hs

@@ -7,6 +7,7 @@ module Wasp.Generator.DbGenerator.Jobs
     runStudio,
     reset,
     seed,
+    dbExecuteTest,
     migrateStatus,
     asPrismaCliArgs,
   )
@@ -113,6 +114,19 @@ seed projectDir seedName =
     projectDir
     (const ["db", "seed"])
 
+-- | Checks if the DB is running and connectable by running
+-- `prisma db execute --stdin --schema <path to db schema>`.
+--  Runs the command in the generated server code directory so it has access to the database URL.
+--
+-- Since nothing is passed to stdin, `prisma db execute` just runs an empty
+-- SQL command, which works perfectly for checking if the database is running.
+dbExecuteTest :: Path' Abs (Dir ProjectRootDir) -> J.Job
+dbExecuteTest projectDir =
+  let absSchemaPath = projectDir </> dbSchemaFileInProjectRootDir
+   in runPrismaCommandAsDbJob
+        projectDir
+        (const ["db", "execute", "--stdin", "--schema", SP.fromAbsFile absSchemaPath])
+
 -- | Runs `prisma studio` - Prisma's db inspector.
 runStudio :: Path' Abs (Dir ProjectRootDir) -> J.Job
 runStudio projectDir = runPrismaCommandAsDbJob projectDir $ \schema ->

waspc/src/Wasp/Generator/DbGenerator/Operations.hs

@@ -6,6 +6,7 @@ module Wasp.Generator.DbGenerator.Operations
     areAllMigrationsAppliedToDb,
     dbReset,
     dbSeed,
+    isDbRunning,
   )
 where
 
@@ -134,6 +135,16 @@ dbSeed genProjectDir seedName = do
     ExitSuccess -> Right ()
     ExitFailure c -> Left $ "Failed with exit code " <> show c
 
+isDbRunning ::
+  Path' Abs (Dir ProjectRootDir) ->
+  IO Bool
+isDbRunning genProjectDir = do
+  chan <- newChan
+  exitCode <- DbJobs.dbExecuteTest genProjectDir chan
+  -- NOTE: We only care if the command succeeds or fails, so we don't look at
+  -- the exit code or stdout/stderr for the process.
+  return $ exitCode == ExitSuccess
+
 generatePrismaClients :: Path' Abs (Dir ProjectRootDir) -> IO (Either String ())
 generatePrismaClients projectRootDir = do
   generateResult <- liftA2 (>>) generatePrismaClientForServer generatePrismaClientForWebApp projectRootDir

waspc/waspc.cabal

@@ -426,6 +426,7 @@ library cli-lib
     Wasp.Cli.Command.Deploy
     Wasp.Cli.Command.Dockerfile
     Wasp.Cli.Command.Info
+    Wasp.Cli.Command.Require
     Wasp.Cli.Command.Start
     Wasp.Cli.Command.Start.Db
     Wasp.Cli.Command.Telemetry