The .nimble extension is now used for both ini and nims .nimble files.

This is done by parsing the .nimble file using the ini parser first, then if that fails evaluating it using nimscript.

src/nimble.nim

@@ -892,6 +892,7 @@ proc guessAuthor(): string =
   return "Anonymous"
 
 proc join(x: seq[PkgTuple]; y: string): string =
+  if x.len == 0: return ""
   result = x[0][0] & " " & $x[0][1]
   for i in 1 ..< x.len:
     result.add y
@@ -899,7 +900,7 @@ proc join(x: seq[PkgTuple]; y: string): string =
 
 proc dump(options: Options) =
   let proj = addFileExt(options.action.projName, NimsExt)
-  let p = if fileExists(proj): readPackageInfo((true, proj))
+  let p = if fileExists(proj): readPackageInfo(proj)
           else: getPkgInfo(os.getCurrentDir())
   echo "name: ", p.name.escape
   echo "version: ", p.version.escape
@@ -1017,9 +1018,7 @@ proc uninstall(options: Options) =
     echo("Removed ", pkg.name, " (", $pkg.version, ")")
 
 proc listTasks(options: Options) =
-  let (isNimScript, nimbleFile) = findNimbleFile(getCurrentDir(), true)
+  let nimbleFile = findNimbleFile(getCurrentDir(), true)
-  if not isNimScript:
-    echo("No tasks defined (Found Nimble file, but no NimScript file)")
   nimscriptsupport.listTasks(nimbleFile)
 
 proc doAction(options: Options) =
@@ -1064,8 +1063,8 @@ proc doAction(options: Options) =
       assert false
     of actionCustom:
       # Custom command. Attempt to call a NimScript task.
-      let (isNimScript, nimbleFile) = findNimbleFile(getCurrentDir(), true)
+      let nimbleFile = findNimbleFile(getCurrentDir(), true)
-      if not isNimScript:
+      if not nimbleFile.isNimScript():
         writeHelp()
       let oldCmd = getNimScriptCommand()
       if not execTask(nimbleFile, oldCmd):

src/nimblepkg/nimbletypes.nim

@@ -11,6 +11,7 @@ type
 
   PackageInfo* = object
     mypath*: string ## The path of this .nimble file
+    isNimScript*: bool ## Determines if this pkg info was read from a nims file
     name*: string
     version*: string
     author*: string

src/nimblepkg/nimscriptsupport.nim

@@ -93,6 +93,16 @@ proc readPackageInfoFromNims*(scriptName: string; result: var PackageInfo) =
   ## Executes the `scriptName` nimscript file. Reads the package information
   ## that it populates.
 
+  # Setup custom error handling.
+  msgs.gErrorMax = high(int)
+  var previousMsg = ""
+  msgs.writeLnHook =
+    proc (output: string) =
+      # The error counter is incremented after the writeLnHook is invoked.
+      if msgs.gErrorCounter > 0:
+        raise newException(NimbleError, previousMsg)
+      previousMsg = output
+
   # Execute the nimscript file.
   execScript(scriptName)
 

src/nimblepkg/packageinfo.nim

@@ -26,7 +26,7 @@ type
   MetaData* = object
     url*: string
 
-  NimbleFile* = tuple[isNimScript: bool; file: string]
+  NimbleFile* = string
 
 proc initPackageInfo(path: string): PackageInfo =
   result.mypath = path
@@ -73,6 +73,12 @@ proc validatePackageInfo(pkgInfo: PackageInfo, path: string) =
           "Version may only consist of numbers and the '.' character " &
           "but found '" & c & "'.")
 
+  if not pkgInfo.isNimScript:
+    # TODO: Turn this into a warning.
+    # TODO: Add a URL explaining more.
+    echo("NOTE: The .nimble file for this project could make use of " &
+         "additional features, if converted into the new NimScript format.")
+
 proc multiSplit(s: string): seq[string] =
   ## Returns ``s`` split by newline and comma characters.
   ##
@@ -169,17 +175,42 @@ proc getNameVersion*(pkgpath: string): tuple[name, version: string] =
       break
 
 proc readPackageInfo*(nf: NimbleFile; onlyMinimalInfo=false): PackageInfo =
-  result = initPackageInfo(nf.file)
+  ## Reads package info from the specifed Nimble file.
-  if nf.isNimScript:
+  ##
+  ## Attempts to read it using the "old" Nimble ini format first, if that
+  ## fails attempts to evaluate it as a nimscript file.
+  ##
+  ## If both fail then returns an error.
+  result = initPackageInfo(nf)
+
+  var success = false
+  var iniError: ref NimbleError
+  # Attempt ini-format first.
+  try:
+    readPackageInfoFromNimble(nf, result)
+    success = true
+    result.isNimScript = false
+  except NimbleError:
+    iniError = (ref NimbleError)(getCurrentException())
+
+  if not success:
     if onlyMinimalInfo:
-      let tmp = getNameVersion(nf.file)
+      let tmp = getNameVersion(nf)
       result.name = tmp.name
       result.version = tmp.version
     else:
-      readPackageInfoFromNims(nf.file, result)
+      try:
-  else:
+        readPackageInfoFromNims(nf, result)
-    readPackageInfoFromNimble(nf.file, result)
+        result.isNimScript = true
-  validatePackageInfo(result, nf.file)
+      except NimbleError:
+        let msg = "Could not read package info file in " & nf & ";\n" &
+                  "  Reading as ini file failed with: \n" &
+                  "    " & iniError.msg & ".\n" &
+                  "  Evaluating as NimScript file failed with: \n" &
+                  "    " & getCurrentExceptionMsg() & "."
+        raise newException(NimbleError, msg)
+
+  validatePackageInfo(result, nf)
 
 proc optionalField(obj: JsonNode, name: string, default = ""): string =
   ## Queries ``obj`` for the optional ``name`` string.
@@ -257,17 +288,14 @@ proc getPackageList*(packagesPath: string): seq[Package] =
     result.add(pkg)
 
 proc findNimbleFile*(dir: string; error: bool): NimbleFile =
-  result = (false, "")
+  result = ""
   var hits = 0
   for kind, path in walkDir(dir):
     if kind == pcFile:
       let ext = path.splitFile.ext
       case ext
       of ".babel", ".nimble":
-        result = (false, path)
+        result = path
-        inc hits
-      of NimsExt:
-        result = (true, path)
         inc hits
       else: discard
   if hits >= 2:
@@ -295,7 +323,7 @@ proc getInstalledPkgs*(libsDir: string):
   for kind, path in walkDir(libsDir):
     if kind == pcDir:
       let nimbleFile = findNimbleFile(path, false)
-      if nimbleFile.file != "":
+      if nimbleFile != "":
         let meta = readMetaData(path)
         result.add((readPackageInfo(nimbleFile, true), meta))
 
@@ -359,6 +387,9 @@ proc getDownloadDirName*(pkg: Package, verRange: VersionRange): string =
     result.add "_"
     result.add verSimple
 
+proc isNimScript*(nf: NimbleFile): bool =
+  readPackageInfo(nf).isNimScript
+
 when isMainModule:
   doAssert getNameVersion("/home/user/.nimble/libs/packagea-0.1") ==
       ("packagea", "0.1")