First versino of code that compiles and passes tests.

waspc/cli/exe/Main.hs

@@ -73,10 +73,13 @@ main = withUtf8 . (`E.catch` handleInternalErrors) $ do
   -- to be more robust than trying to only check for commands that require it.
   -- See https://github.com/wasp-lang/wasp/issues/1134#issuecomment-1554065668
   NodeVersion.getAndCheckNodeVersion >>= \case
-    Left errorMsg -> do
+    NodeVersion.VersionCheckFail errorMsg -> do
       cliSendMessage $ Message.Failure "Node requirement not met" errorMsg
       exitFailure
-    Right _ -> pure ()
+    NodeVersion.VersionCheckSuccess maybeWarning _version ->
+      case maybeWarning of
+        Just warnMsg -> cliSendMessage $ Message.Warning "Node version warning" warnMsg
+        Nothing -> pure ()
 
   case commandCall of
     Command.Call.New newArgs -> runCommand $ createNewProject newArgs

waspc/data/Generator/templates/server/tsconfig.json

@@ -1,5 +1,6 @@
+{{={= =}=}}
 {
-  "extends": "@tsconfig/node18/tsconfig.json",
+  "extends": "@tsconfig/node{= majorNodeVersion =}/tsconfig.json",
   "compilerOptions": {
     // Overriding this until we implement more complete TypeScript support.
     "strict": false,
@@ -8,7 +9,7 @@
     "target": "es2017",
     // Enable source map for debugging
     "sourceMap": true,
-    // The remaining settings should match node18/tsconfig.json, but I kept
+    // The remaining settings should match the extended nodeXY/tsconfig.json, but I kept
     // them here to be explicit.
 
     // Enable default imports in TypeScript.

waspc/src/Wasp/Generator/DockerGenerator.hs

@@ -29,7 +29,7 @@ import Wasp.Generator.FileDraft (FileDraft (..), createTemplateFileDraft)
 import qualified Wasp.Generator.FileDraft.TemplateFileDraft as TmplFD
 import Wasp.Generator.Monad (Generator, GeneratorError, runGenerator)
 import Wasp.Generator.Templates (TemplatesDir, compileAndRenderTemplate)
-import Wasp.Node.Version (latestMajorNodeVersion)
+import qualified Wasp.Node.Version as V
 import qualified Wasp.SemanticVersion as SV
 import Wasp.Util (getEnvVarDefinition)
 
@@ -49,7 +49,7 @@ genDockerfile spec = do
             [ "usingPrisma" .= not (null $ AS.getDecls @AS.Entity.Entity spec),
               "serverPrismaClientOutputDirEnv" .= getEnvVarDefinition serverPrismaClientOutputDirEnv,
               "dbSchemaFileFromServerDir" .= SP.fromRelFile dbSchemaFileFromServerDir,
-              "nodeMajorVersion" .= show (SV.major latestMajorNodeVersion),
+              "nodeMajorVersion" .= show (SV.major V.oldestWaspSupportedNodeVersion),
               "userDockerfile" .= fromMaybe "" (AS.userDockerfileContents spec)
             ]
       )

waspc/src/Wasp/Generator/Job/Process.hs

@@ -22,7 +22,7 @@ import qualified System.Info
 import qualified System.Process as P
 import UnliftIO.Exception (bracket)
 import qualified Wasp.Generator.Job as J
-import qualified Wasp.Node.Version as NodeVersion
+import qualified Wasp.Node.Version as V
 
 -- TODO:
 --   Switch from Data.Conduit.Process to Data.Conduit.Process.Typed.
@@ -96,9 +96,11 @@ runNodeCommandAsJob = runNodeCommandAsJobWithExtraEnv []
 
 runNodeCommandAsJobWithExtraEnv :: [(String, String)] -> Path' Abs (Dir a) -> String -> [String] -> J.JobType -> J.Job
 runNodeCommandAsJobWithExtraEnv extraEnvVars fromDir command args jobType chan =
-  NodeVersion.getAndCheckNodeVersion >>= \case
-    Left errorMsg -> exitWithError (ExitFailure 1) (T.pack errorMsg)
-    Right _ -> do
+  V.getAndCheckNodeVersion >>= \case
+    V.VersionCheckFail errorMsg -> exitWithError (ExitFailure 1) (T.pack errorMsg)
+    -- We don't print the warning message here because `wasp CLI` already likely printed it,
+    -- so it would be too much noise.
+    V.VersionCheckSuccess _maybeWarning _version -> do
       envVars <- getAllEnvVars
       let nodeCommandProcess = (P.proc command args) {P.env = Just envVars, P.cwd = Just $ SP.fromAbsDir fromDir}
       runProcessAsJob nodeCommandProcess jobType chan

waspc/src/Wasp/Generator/ServerGenerator.hs

@@ -74,8 +74,8 @@ genServer :: AppSpec -> Generator [FileDraft]
 genServer spec =
   sequence
     [ genFileCopy [relfile|README.md|],
-      genFileCopy [relfile|tsconfig.json|],
       genFileCopy [relfile|nodemon.json|],
+      genTsConfigJson,
       genPackageJson spec (npmDepsForWasp spec),
       genNpmrc,
       genGitignore
@@ -116,6 +116,18 @@ genDotEnv spec =
 dotEnvInServerRootDir :: Path' (Rel ServerRootDir) File'
 dotEnvInServerRootDir = [relfile|.env|]
 
+genTsConfigJson :: Generator FileDraft
+genTsConfigJson = do
+  return $
+    C.mkTmplFdWithDstAndData
+      (C.asTmplFile [relfile|tsconfig.json|])
+      (C.asServerFile [relfile|tsconfig.json|])
+      ( Just $
+          object
+            [ "majorNodeVersion" .= show (major NodeVersion.oldestWaspSupportedNodeVersion)
+            ]
+      )
+
 genPackageJson :: AppSpec -> N.NpmDepsForWasp -> Generator FileDraft
 genPackageJson spec waspDependencies = do
   combinedDependencies <- N.genNpmDepsForPackage spec waspDependencies
@@ -127,7 +139,7 @@ genPackageJson spec waspDependencies = do
           object
             [ "depsChunk" .= N.getDependenciesPackageJsonEntry combinedDependencies,
               "devDepsChunk" .= N.getDevDependenciesPackageJsonEntry combinedDependencies,
-              "nodeVersionRange" .= show NodeVersion.nodeVersionRange,
+              "nodeVersionRange" .= (">=" <> show NodeVersion.oldestWaspSupportedNodeVersion),
               "startProductionScript"
                 .= ( (if hasEntities then "npm run db-migrate-prod && " else "")
                        ++ "NODE_ENV=production npm run start"
@@ -179,12 +191,14 @@ npmDepsForWasp spec =
             ("typescript", "^5.1.0"),
             ("@types/express", "^4.17.13"),
             ("@types/express-serve-static-core", "^4.17.13"),
-            ("@types/node", "^18.11.9"),
-            ("@tsconfig/node" ++ show (major NodeVersion.latestMajorNodeVersion), "^1.0.1"),
+            ("@types/node", "^" <> majorNodeVersionStr <> ".0.0"), -- TODO: This is challenging hm, can we do something better?
+            ("@tsconfig/node" <> majorNodeVersionStr, "^1.0.1"),
             ("@types/uuid", "^9.0.0"),
             ("@types/cors", "^2.8.5")
           ]
     }
+  where
+    majorNodeVersionStr = show (major NodeVersion.oldestWaspSupportedNodeVersion)
 
 genNpmrc :: Generator FileDraft
 genNpmrc =

waspc/src/Wasp/Generator/WebAppGenerator.hs

@@ -120,7 +120,7 @@ genPackageJson spec waspDependencies = do
             [ "appName" .= (fst (getApp spec) :: String),
               "depsChunk" .= N.getDependenciesPackageJsonEntry combinedDependencies,
               "devDepsChunk" .= N.getDevDependenciesPackageJsonEntry combinedDependencies,
-              "nodeVersionRange" .= show NodeVersion.nodeVersionRange
+              "nodeVersionRange" .= (">=" <> show NodeVersion.oldestWaspSupportedNodeVersion)
             ]
       )
 

waspc/src/Wasp/Node/Version.hs

@@ -1,10 +1,7 @@
 module Wasp.Node.Version
   ( getAndCheckNodeVersion,
-    getNodeVersion,
-    nodeVersionRange,
-    latestMajorNodeVersion,
-    waspNodeRequirementMessage,
-    makeNodeVersionMismatchMessage,
+    VersionCheckResult (..),
+    oldestWaspSupportedNodeVersion,
   )
 where
 
@@ -16,26 +13,53 @@ import qualified Text.Regex.TDFA as R
 import qualified Wasp.SemanticVersion as SV
 import Wasp.Util (indent)
 
+-- | Wasp supports any node version equal or greater to this version.
+-- | We usually keep this one equal to the latest LTS.
+oldestWaspSupportedNodeVersion :: SV.Version
+oldestWaspSupportedNodeVersion = SV.Version 20 8 1
+
+data VersionCheckResult
+  = VersionCheckFail !ErrorMessage
+  | VersionCheckSuccess !(Maybe WarningMessage) !SV.Version
+
+type WarningMessage = String
+
+type ErrorMessage = String
+
 -- | Gets the installed node version, if any is installed, and checks that it
 -- meets Wasp's version requirement.
---
--- Returns a string representing the error
--- condition if node's version could not be found or if the version does not
--- meet the requirements.
-getAndCheckNodeVersion :: IO (Either String SV.Version)
+getAndCheckNodeVersion :: IO VersionCheckResult
 getAndCheckNodeVersion =
   getNodeVersion >>= \case
-    Left errorMsg -> return $ Left errorMsg
-    Right nodeVersion ->
-      if SV.isVersionInRange nodeVersion nodeVersionRange
-        then return $ Right nodeVersion
-        else return $ Left $ makeNodeVersionMismatchMessage nodeVersion
+    Left errorMsg -> return $ VersionCheckFail errorMsg
+    Right userNodeVersion ->
+      return $
+        if SV.isVersionInRange userNodeVersion $ SV.Range [SV.gte oldestWaspSupportedNodeVersion]
+          then VersionCheckSuccess Nothing userNodeVersion
+          else VersionCheckFail $ makeNodeVersionMismatchMessage userNodeVersion
+
+makeNodeVersionMismatchMessage :: SV.Version -> String
+makeNodeVersionMismatchMessage nodeVersion =
+  unlines
+    [ unwords
+        [ "Your Node version does not meet Wasp's requirements!",
+          "You are running Node " ++ show nodeVersion ++ "."
+        ],
+      waspNodeRequirementMessage
+    ]
+
+waspNodeRequirementMessage :: String
+waspNodeRequirementMessage =
+  unwords
+    [ "Wasp requires Node >=" ++ show oldestWaspSupportedNodeVersion ++ " to be installed and in PATH.",
+      "Check Wasp documentation for more details: https://wasp-lang.dev/docs/quick-start#requirements."
+    ]
 
 -- | Gets the installed node version, if any is installed, and returns it.
 --
 -- Returns a string representing the error condition if node's version could
 -- not be found.
-getNodeVersion :: IO (Either String SV.Version)
+getNodeVersion :: IO (Either ErrorMessage SV.Version)
 getNodeVersion = do
   -- Node result is one of:
   -- 1. @Left processError@, when an error occurs trying to run the process
@@ -90,34 +114,3 @@ makeNodeUnknownErrorMessage err =
     [ "An unknown error occured while trying to run `node --version`:",
       indent 2 $ show err
     ]
-
-waspNodeRequirementMessage :: String
-waspNodeRequirementMessage =
-  unwords
-    [ "Wasp requires Node " ++ show nodeVersionRange ++ " to be installed and in PATH.",
-      "Check Wasp documentation for more details: https://wasp-lang.dev/docs/quick-start#requirements."
-    ]
-
-nodeVersionRange :: SV.Range
-nodeVersionRange = SV.Range [SV.backwardsCompatibleWith latestNodeLTSVersion]
-
-latestNodeLTSVersion :: SV.Version
-latestNodeLTSVersion = SV.Version 18 12 0
-
--- | Latest concrete major node version supported by the nodeVersionRange, and
---   therefore by Wasp.
---   Here we assume that nodeVersionRange is using latestNodeLTSVersion as its basis.
---   TODO: instead of making assumptions, extract the latest major node version
---   directly from the nodeVersionRange.
-latestMajorNodeVersion :: SV.Version
-latestMajorNodeVersion = latestNodeLTSVersion
-
-makeNodeVersionMismatchMessage :: SV.Version -> String
-makeNodeVersionMismatchMessage nodeVersion =
-  unlines
-    [ unwords
-        [ "Your Node version does not meet Wasp's requirements!",
-          "You are running Node " ++ show nodeVersion ++ "."
-        ],
-      waspNodeRequirementMessage
-    ]

waspc/src/Wasp/NodePackageFFI.hs

@@ -19,7 +19,7 @@ import System.IO (hPutStrLn, stderr)
 import qualified System.Process as P
 import Wasp.Data (DataDir)
 import qualified Wasp.Data as Data
-import Wasp.Node.Version (getAndCheckNodeVersion)
+import qualified Wasp.Node.Version as V
 
 data Package
   = DeployPackage
@@ -53,10 +53,11 @@ scriptInPackageDir = [relfile|dist/index.js|]
 -- the dependencies.
 getPackageProcessOptions :: Package -> [String] -> IO P.CreateProcess
 getPackageProcessOptions package args = do
-  getAndCheckNodeVersion >>= \case
-    Right _ -> pure ()
-    Left errorMsg -> do
-      -- Exit if valid node version is not installed
+  V.getAndCheckNodeVersion >>= \case
+    -- We don't print the warning message here because `wasp CLI` already likely printed it,
+    -- so it would be too much noise.
+    V.VersionCheckSuccess _maybeWarning _version -> pure ()
+    V.VersionCheckFail errorMsg -> do
       hPutStrLn stderr errorMsg
       exitFailure
   packageDir <- getPackageDir package